+
+ 
+
+
+ Martes 06 de julio | Operación bikini, quítate esos servers que te sobran por @awsvalenciaes
+VLCTechHub Feed 08 07 2021
+
+
+ WhatsApp permitirá enviar fotografías y vídeos que se eliminan automáticamente tras ser vistos
+Blog elhacker.NET 06 07 2021
+
+ 
+
+
+ How to be more productive
+Work Chronicles 06 07 2021
+The post How to be more productive appeared first on Work Chronicles.
+ +
+
+ +Software Engineering Manager (Clojure Team) +
++Brave Clojure Jobs + 06 07 2021
+Software Engineering Manager (Clojure Team)
Banzai Inc. | Anywhere | US & Canada
remote
Unparalleled financial education.
$125000 - $200000
tl;dr
+-
+
- Manager, or senior-level developer moving to management +
- Direct software engineering for a growing ed-tech firm +
- Functional programming experience a plus +
- Remote (if desired), competitive salary, unbeatable health insurance, and generous PTO +
What we're looking for
Senior-level developer looking for management experience, or experienced manager furthering his or her career.
Culturally, we tend to promote from within; for this position, however, we want you to introduce stronger programming standards, mentor younger developers, and generally help us reach bigger goals we have as a company.
What you will do
Banzai's development group consists of three Clojure devs, an architect, and two JavaScript devs, with one more front-end position currently open. You will shape the team according to your own vision; vet and hire future engineers; measure individual performance; and demonstrate how to hit company goals. You will lead by example.
We have two initiatives: create more complex types of interactive software for schools, banks, and credit unions; and complete a greenfield project for small- to mid-size businesses helping employers deepen their employees' understanding of their benefits.
While you will be a manager first, you may also contribute to the code: we believe great managers stay close to the problems their teams face daily. You will report to the Head of Product.
What we expect
You have well-developed opinions about leading people, organizing processes, and writing software.
Our front-end stack is built on JavaScript, with a Clojure backend. While you do not need Clojure experience, familiarity with innovative tooling native to functional programming is a plus (e.g. REPL-driven development, React, Vue, Elm, RxJS, Elixir, F#, etc.).
You have a deep understanding of programming for the web, including monitoring performance, deploying, testing, reviewing code, and generally helping us understand what's required of a company with more developers than we have.
Our architecture
Our software architecture is based around a monolithic repository with several application and worker subsystems running on a PaaS. Three of our web applications are SPAs, and two are server-driven templating engines. The Clojure code has more than 50% test coverage. We use a host of caching mechanisms to help keep the site running at or below 50ms at the 95th percentile.
We hope you will find new ways to help us improve the architecture for the sake of the business.
What we're offering
Our goal is to make sure you're not worried about benefits:
Our product team offers a competitive salary, reviewed every six months. We don't like offer wars, and you shouldn't have to switch jobs for a raise. Every six months we'll discuss your pay in a simple performance review. It's common for employees to get raises at each review, assuming the company is growing and you're regularly hitting expectations.
You may work remotely or join us at our office.
Best of all we offer full-health care coverage. We cover ~95% of your insurance premium, and all of your out-of-pocket expenses via a reimbursable account. You will get access to a Flexible Spending Account (FSA), letting you purchase things like eyeglasses and over-the-counter medications tax free.
Paid time off (PTO) is very flexible. We recommend three business weeks per year, in addition to a generous holiday schedule. There is, however, no technical limit inasmuch as it is approved with your manager and you're regularly hitting company goals.
We offer a 401(k) with a generous 5% match, with a wide variety of investment options. Half of your employer contributions will vest in one year, the remainder in two.
You will be eligible for company stock options. The options plan is simple and straightforward, with a four-year vesting schedule. When your options vest, you will have the opportunity to buy them and become an owner of company stock, if you choose.
You will be set you up with a phone and company-paid service.
Additional benefits include life and disability insurance, food and drinks on company premises, and other fringes. Should you become a parent (either for the first time or again!), you will have access to plenty of paid leave.
Finally, while strong benefits are essential to Banzai's compensation package, more importantly, you will have varied and interesting opportunities to grow in your careerand assume meaningful responsibility. You will be expected to learn new things on your own, but we also make time for training.
Tell me about the company
Banzai is an independent, owner-operated technology company dedicated to helping people become wise stewards of their finances through online solutions and local partnerships. We employ over 50 professionals in management, sales, sponsor relations, support, public relations, and product development.
Owner operated
Banzai has been in business for nearly 15 years, and the company's co-founders continue to lead it today. While we are aggressively growth-minded, the company is profitable, self-sustaining, and it requires neither debt nor venture funding.
Banzai is unique in the technology industry---our mindset is long-term. No unrealistic growth targets; no investor drama; no chasing unicorns. We aim for steady, reliable growth that compounds over time, making the company a more lucrative, happier place for employees in the long run.
Oh, and you can be an owner too: every full-time employee receives a stock option grant.
+-
+
- www.teachbanzai.com +
- Located @ 2230 N. University Pkwy., Bldg. 14, Provo Utah +
Tell me about the culture
Banzai's culture marries a high level of trust and flexibility with equally high levels of responsibility. We place important jobs on our employees' shoulders, even juniors. For leadership, we tend to promote from within.
We ask you to bring your best self to work.
Meeting these expectations also earns you a great deal of freedom. At Banzai we don't count hours, nor do we set your schedule. (Although it is generally expected that you will work 40 hours per week.) Your personal time is your own; there's plenty of space in the day to take breaks and run errands; and our holiday schedule and PTO policy is generous. Fire drills and late nights are rare.
How do I apply?
We want to see what you've accomplished. Please send a portfolio and cover letter explaining why you're a great fit to Kendall Buchanan, CTO, kendall [at] teachbanzai.com.
+
+ Microsoft recomienda Linux como reemplazo de SQL Server en Windows Containers
+MuyLinux 06 07 2021
+
+
+ IV Mar i jazz
+AU Agenda 06 07 2021
+La entrada IV Mar i jazz aparece primero en AU Agenda.
+PARC DR. LLUCH marijazz.es Ara més que mai necessitem música, oci i cultura, i millor si és en un espai obert. D’aqueixa necessitat nasqueren les Jam Sesions en 27 Amigos, un bar insígnia del barri del Cabanyal que ara, amb recolzament de l’Ajuntament de València, Sedajazz i l’Associació de Comerciants del Marítim, ens porta Mar […]
+La entrada IV Mar i jazz aparece primero en AU Agenda.
+ +
+
+ XI Russafa Escència
+AU Agenda 06 07 2021
+La entrada XI Russafa Escència aparece primero en AU Agenda.
+russafaescenica.com El festival Russafa Escènica se expande como una gota de aceite, ahora con un proyecto de residencias artísticas en diferentes municipios de la provincia llamado Via Escènica. Al cierre de la edición de esta revista, el festival estaba en pleno proceso de selección de los viveros (30 min.) y los bosques (60 min.) de […]
+La entrada XI Russafa Escència aparece primero en AU Agenda.
+ +
+
+ Descubren 9 aplicaciones Android que roban credenciales de Facebook
+Blog elhacker.NET 06 07 2021
+
+
+ 31è MIM
+AU Agenda 06 07 2021
+La entrada 31è MIM aparece primero en AU Agenda.
+mimsueca.com Torna la Mostra Internacional de MIM de Sueca aquest setembre amb companyies de Portugal, Brasil, Xile, Alemanya, França i Regne Unit, sense por a les fronteres. De les illes britàniques venen Gandini Juggling per presentar 4×4: Ephemeral architectures, on quatre malabaristes i quatre ballarins de ballet comparteixen escenari. Francesos son Cie. Bivouac, que alternen […]
+ + +
+
+ Bürstner Club
+AU Agenda 06 07 2021
+La entrada Bürstner Club aparece primero en AU Agenda.
+ESPACIO INESTABLE. Aparisi i Guijarro, 7 Dels altres es una joven compañía valenciana fundada en el año 2020 y dirigida por Eleonora Gronchi i Pablo Meneu para darle una vuelta al circo contemporáneo. Han creado piezas como Staged para la compañía Circumference (galardonada con el Total TheatreAward del Festival Fringe de Edinburgo 2019 como mejor espectáculo de […]
+La entrada Bürstner Club aparece primero en AU Agenda.
+ +
+
+ Espaldas de plata
+AU Agenda 06 07 2021
+La entrada Espaldas de plata aparece primero en AU Agenda.
+SALA ULTRAMAR. Alzira, 9 De veritat en Àfrica s’escolten tambors en la llunyania, a totes hores, com en els sons d’ambient insufribles dels zoos? Walter no ho sap, mai ha estat allí. En l’agència de publicitat en la qual treballa té l’“oportunitat” d’acceptar un encàrrec per a un home, un polític a qui detesta, però […]
+La entrada Espaldas de plata aparece primero en AU Agenda.
+ +
+
+ Señora de rojo sobre fondo gris
+AU Agenda 06 07 2021
+La entrada Señora de rojo sobre fondo gris aparece primero en AU Agenda.
+TEATRO OLYMPIA. Sant Vicent Màrtir, 44 Delibes y José Sacristán, una fórmula que ya ha demostrado funcionar a la perfección en este soliloquio dirigido por José Sámano. Un pintor con una carrera dilatada, Nicolás, padece una importante crisis existencial, su creatividad se ha esfumado tras la muerte de su mujer. El fondo gris que imprima […]
+La entrada Señora de rojo sobre fondo gris aparece primero en AU Agenda.
+ +
+
+ V Cicle Escèniques LGTBI
+AU Agenda 06 07 2021
+La entrada V Cicle Escèniques LGTBI aparece primero en AU Agenda.
+CARME TEATRE. Gregori Gea, 6 Dansa de València, Madrid, Galícia i Canàries és el que ofereix la cinquena edició del Cicle Escèniques LGTBI del Carme Teatre, on el plat primícia arriba en forma d’entrant. Arrenca la mostra amb l’estrena absoluta de Nus-altres possibles del valencià Javier J. Hedrosa [2-5], un habitual de La Coja Dansa […]
+La entrada V Cicle Escèniques LGTBI aparece primero en AU Agenda.
+ +
+
+ Maixabel
+AU Agenda 06 07 2021
+La entrada Maixabel aparece primero en AU Agenda.
+Icíar Bollaín · España · 2021 · Guion: Icíar Bollaín e Isa Campo · Intérpretes: Blanca Portillo, Luis Tosar, Bruno Sevilla… Reparto de lujo con dos grandes de la interpretación en España como Blanca Portillo y Luis Tosar. Maixabel cuenta la historia de Maixabel Lasa, mujer del político Juan María Jaúregui, asesinado por ETA en el […]
+ + +
+
+ Cuestión de sangre
+AU Agenda 06 07 2021
+La entrada Cuestión de sangre aparece primero en AU Agenda.
+Tom McCarthy · USA · 2021 · Guión: Thomas Bidegain, Noé Debré, Marcus Hinchey y Tom McCarthy · Intérpretes: Matt Damon, Abigail Breslin, Camille Cottin… El realizador de la galardonada Spotlight regresa con este largometraje que transita los códigos del thriller y el drama político y social. En Cuestión de sangre, Matt Damon interpreta a […]
+La entrada Cuestión de sangre aparece primero en AU Agenda.
+ +
+
+ BABii
+AU Agenda 06 07 2021
+La entrada BABii aparece primero en AU Agenda.
+CENTRE DEL CARME. Museu, 2 Escoltar MiiRROR, l’àlbum de la talentosa artista multidisciplinària britànica BABii, és endinsar-se en l’atmosfera vaporosa i etèria d’un pop electrònic i garage, és evolucionar en el cor d’una realitat paral·lela que explora les emocions íntimes i els dimonis interiors de la seua creadora. BABii, en una estètica alienadora do it […]
+ + +
+ 
+
+
+ An Hour About… Psuedo.com
+The History of the Web 06 07 2021
+Pseudo.com is a forgotten relic of the dot-com era. Was it ahead of its time? A moonshot that went too far? Or simply a piece of elaborate performance art?
+The post An Hour About… Psuedo.com appeared first on The History of the Web.
+ +
+
+ Acusan a Audacity de convertirse en ‘spyware’ y cada vez pinta peor todo
+MuyLinux 05 07 2021
+
+
+ darktable 3.6 llega con grandes mejoras en la gestión del color
+MuyLinux 05 07 2021
+
+
+ Ciberataque global del ransomware REvil afecta a miles de empresas
+Blog elhacker.NET 05 07 2021
+
+ 
+
+
+ Designing Machine Learning for DVC Studio
+Martian Chronicles, Evil Martians’ team blog 05 07 2021
+
+ 
+
+
+ CUÑADOS
+Cinestudio d'Or 04 07 2021
+
del 5 al 11 de julio
17:15h. 20:55h. versión doblada / digital
+ 
+
+
+ BORRAR EL HISTORIAL
+Cinestudio d'Or 04 07 2021
+
del 5 al 11 de julio
19:00h. versión doblada / digital
+ 
+
+
+ UNA JOVEN PROMETEDORA
+Cinestudio d'Or 04 07 2021
+
+ 
+
+
+ Radar verano mix Parte 1
+República Web 03 07 2021
+Debido a un error de grabación la pista de Antony no está disponible. Esta primera parte es una versión editada con las partes de Antony (que no salen en la mezcla). Intentaremos que Antony grabe sus enlaces por separado para la parte 2.
+ + + +Despedimos temporada 4 del podcast con un episodio cargado de enlaces de interés, salpicados eso sí, con nuestras anotaciones personales. Como es habitual en la sección Radar, este episodio recoge recursos y herramientas que nos parecen valiosas para nuestro trabajo. En esta primera parte se incluyen las recomendaciones recopiladas por Javier y Andros. También al inicio del podcast David Vaquero hace un valoración del Congreso Eslibre que se celebró la semana pasada, y que tuvo al propio David participando como colaborador y dando un taller. Andros también participó ofreciendo una charla sobre el desarrollo de Glosa, su solución personal para agregar comentarios en un sitio web estático.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+ 
+
+
+ RUEGA POR NOSOTROS
+Cinestudio d'Or 03 07 2021
+
+
+
+
+ Greatest weakness
+Work Chronicles 03 07 2021
+The post Greatest weakness appeared first on Work Chronicles.
+ +
+
+ Publicada herramienta descifrado gratuita para víctimas del ransomware Lorenz
+Blog elhacker.NET 03 07 2021
+
+
+ Europol cierra servicio de VPN DoubleVPN utilizado por cibercriminales
+Blog elhacker.NET 02 07 2021
+
+
+ KDE Connect: la mejor integración con Android llega a Windows
+MuyLinux 02 07 2021
+
+
+ Apply to be the FSF's next executive director
+FSF News 02 07 2021
+
+
+ Operadores de Telefonía añaden enlaces publicidad en los mensajes SMS recibidos
+Blog elhacker.NET 02 07 2021
+
+
+ Clojure Deref (July 2, 2021)
+Clojure News 02 07 2021
+
+
+
+
+
+
+Welcome to the Clojure Deref! This is a weekly link/news roundup for the Clojure ecosystem. (@ClojureDeref RSS)
+
+
+Highlights
+
+
+
+
+Clojurists Together announced a more varied set of funding models moving forward to better match what projects have been seeking.
+
+
+All of the clojureD 2021 videos are now available, including my video discussing a set of new Clojure CLI features and the tools.build library. We have been hard at work polishing documentation and finalizing a last few bits of the source prep functionality and we expect it will be available soon for you to work with! For now, the video is a good overview of what’s coming: expanded source for source-based libs, a new tools.build library, and some extensions to tool support in the Clojure CLI.
+
+
+In the core
+
+
+
+
+We have mostly been working on Clojure CLI and tools.build lately but these items went by this week, maybe of interest:
+
+
+-
+
-
+
Does Clojure still have rooms to improve at compiler level? - some discussion at ClojureVerse
+
+ -
+
CLJ-2637 - Automatic argument conversion to Functional Interface (Lambda) from Clojure fn - this patch was proposed to do automatic SAM conversion for Clojure functions in the compiler.
+
+
+
+This is an area we’ve actually spent a lot of time thinking about for Clojure 1.11, (tracking under CLJ-2365 although most of the work has happened off ticket). In particular we have talked about a long list of possible use cases for functional interop and also a long list of ideas for making functional interop less cumbersome, both syntax and implementation. The examples given in CLJ-2637 are primarily about the Java Stream API but we don’t think that’s particularly high on the list of what’s interesting (if you’re in Clojure, just use Clojure’s apis!). But there are cases where you have Java APIs in the JDK or elsewhere that now take one of the SAM-style interfaces, or a java.function interface and it would be nice to reduce the friction in passing a Clojure function without needing to reify - either by automatic detection and conversion, or helper fns, or even new syntax and compiler support. No conclusions yet.
+
+
+Podcasts and videos
+
+
+
+
+-
+
-
+
Apropos - Mia, Mike, Ray, and Eric chat about Clojure
+
+
+
+Blogs, discussions, tutorials
+
+
+
+
+-
+
-
+
Clojure Morsels - a new biweekly mailing list for Clojure news starting soon
+
+ -
+
REPL vs CLI: IDE wars - Vlad thinks about REPLs vs the command line for dev
+
+ -
+
Clojure Building Blocks - Gustavo Santos
+
+ -
+
Getting Started with Clojure - Gustavo Santos
+
+ -
+
Rich Comment Blocks - Thomas Mattacchione
+
+
+
+Training and hiring
+
+
+
+
+-
+
-
+
Learn Datomic - is a new course for learning Datomic and Datalog by Jacek Schae, coming soon!
+
+ -
+
Who’s Hiring - monthly hiring thread on Clojure subreddit
+
+
+
+
+ Libraries and tools
+
+
+
+
+Some interesting library and tool updates and posts this week:
+
+
+-
+
-
+
PCP - Clojure replacement for PHP
+
+ -
+
holy-lambda 0.2.2 - A micro-framework that integrates Clojure with AWS Lambda on either Java, Clojure Native, or Babashka runtime
+
+ -
+
clojure-lsp 2021.07.01-13.46.18 - Language Server (LSP) for Clojure, this release with new API/CLI support!
+
+ -
+
clojureflare - a new ClojureScript lib for using Cloudflare workers
+
+ -
+
Calva 2.0.202 - Clojure & ClojureScript in Visual Studio Code
+
+
+
+ Debugging Series 2021: Summer Break!
+Giant Robots Smashing Into Other Giant Robots 02 07 2021
+
+
+ 30 millones ordenadores Dell vulnerables por culpa software preinstalado
+Blog elhacker.NET 01 07 2021
+
+
+ Descubren un importante fallo de seguridad en los paquetes RPM
+MuyLinux 01 07 2021
+
+
+
+
+ Speed of execution
+Work Chronicles 01 07 2021
+The post Speed of execution appeared first on Work Chronicles.
+ +
+
+ FSF takes next step in commitment to improving board governance
+FSF News 01 07 2021
+
+ 
+
+
+
+ No sin mis cookies 01 07 2021
+Si hasta 2020 el SEO local era importante, ahora toma el carácter de plenamente imprescindible. Si competir ya es de por sí difícil, hacerlo con tus vecinos de localidad es todo un desafío.
+The post appeared first on No sin mis cookies.
+ +
+
+ Deepin estrena tienda de software con soporte para aplicaciones de Android
+MuyLinux 01 07 2021
+
+
+ Grupo MASMOVIL España hackeado por el ransomware de origen ruso REvil (Sodinokibi)
+Blog elhacker.NET 01 07 2021
+
+
+ Grave vulnerabilidad en el servicio de impresión de Windows: PrintNightmare
+Blog elhacker.NET 01 07 2021
+
+
+ WD recuperará los datos borrados durante el ataque a sus NAS My Book Live y ofrecerá descuentos
+Blog elhacker.NET 30 06 2021
+
+
+ System76 anuncia Pop!_OS 21.04 con COSMIC, su nuevo escritorio
+MuyLinux 30 06 2021
+
+
+ 667
+Extra Ordinary 30 06 2021
+
+
+ GitHub presenta Copilot; herramienta capaz de autocompletar y generar código con Inteligencia Artificial (IA)
+Blog elhacker.NET 30 06 2021
+
+
+
+
+ Expertise
+Work Chronicles 30 06 2021
+The post Expertise appeared first on Work Chronicles.
+ +
+
+ JWM Logo
+tonsky.me 30 06 2021
+
+
+ Detectan colisiones entre estrellas de neutrones y agujeros negros
+NeoFronteras 29 06 2021
+
+
+ A la venta base de datos con datos del 92% usuarios de Linkedin
+Blog elhacker.NET 29 06 2021
+
+
+ Sin agua en Venus y posiblemente sin vida
+NeoFronteras 29 06 2021
+
+
+ Nitrux 1.5 llega con KDE Plasma 5.22 y el reciente Linux 5.13
+MuyLinux 29 06 2021
+
+
+ Herramientas gratuitas análisis forense digital
+Blog elhacker.NET 29 06 2021
+
+ 
+
+
+ Introducing GitHub Copilot: your AI pair programmer
+The GitHub Blog 29 06 2021
+
+
+ Windows 11 TPM; requisitos y características
+Blog elhacker.NET 29 06 2021
+
+
+ New Case Study & Updated Services for Early-Stage Teams
+Giant Robots Smashing Into Other Giant Robots 29 06 2021
+
+
+ Google Summer of Code 2021: Student Stats
+Google Open Source Blog 28 06 2021
+
+
+ Trickbot: botnet malware-as-a-service
+Blog elhacker.NET 28 06 2021
+
+
+ Disponible Linux 5.13 con soporte inicial para el Apple M1 y mejoras de seguridad
+MuyLinux 28 06 2021
+
+ 
+
+
+ The Lightness of Windows
+Stratechery by Ben Thompson 28 06 2021
+
+
+
+
+ Follow Through
+Work Chronicles 28 06 2021
+The post Follow Through appeared first on Work Chronicles.
+ +
+
+ Tecnología GPON - FTTH
+Blog elhacker.NET 28 06 2021
+
+
+ The next phase of Clojurists Together
+News on Clojurists Together 28 06 2021
+
+
+ Demystifying styled-components
+Josh Comeau's blog 27 06 2021
+
+
+ Graves vulnerabilidades NAS WD My Book Live provocan ataque externo con borrado entero de la unidad
+Blog elhacker.NET 26 06 2021
+
+
+ Microsoft presenta oficialmente Windows 11
+Blog elhacker.NET 26 06 2021
+
+
+ El interferómetro magnético podría explorar la gravedad cuántica
+NeoFronteras 25 06 2021
+
+
+
+
+ Wonder Why
+Work Chronicles 25 06 2021
+The post Wonder Why appeared first on Work Chronicles.
+ +
+
+
+
+ Seven years of the GitHub Security Bug Bounty program
+The GitHub Blog 25 06 2021
+
+
+ Canonical ofrecerá soporte empresarial para Blender LTS
+MuyLinux 25 06 2021
+
+
+ Clojure Deref (June 25, 2021)
+Clojure News 25 06 2021
+
+
+
+
+
+
+Welcome to the Clojure Deref! This is a weekly link/news roundup for the Clojure ecosystem. (@ClojureDeref RSS)
+
+
+Highlights
+
+
+
+
+It is common to see complaints that both Clojure jobs and Clojure developers are hard to find. The real truth is: both exist, but there is sometimes a mismatch in either experience or geographic distribution. We don’t typically highlight jobs in the Deref but here are some great places to find Clojure jobs:
+
+
+-
+
-
+
Brave Clojure - job board
+
+ -
+
Functional Works - job board
+
+ -
+
Clojurians slack - #jobs and #remote-jobs channel
+
+ - + + +
-
+
Clojure subreddit - monthly thread
+
+ -
+
Who is hiring - search at HackerNews
+
+ - + + +
+
+Also, I want to highlight that clojureD 2021 conference videos are coming out now, about one per day, check them out!
+
+
+Sponsorship spotlight
+
+
+
+
+Over the last couple years, the Calva team has been putting a ton of effort into making VS Code a great place to Clojure. If you enjoy the fruits of that effort, consider supporting one of these fine folks working in this area:
+
+
+-
+
-
+
Peter Strömberg - sponsor for Calva
+
+ -
+
Brandon Ringe - sponsor for Calva
+
+ -
+
Eric Dallo - sponsor for clojure-lsp
+
+
+
+Podcasts and videos
+
+
+
+
+-
+
-
+
CaSE - Conversations about Software Engineering talks with Eric Normand
+
+ -
+
ClojureScript podcast - Jacek Schae interviews Howard Lewis Ship
+
+ -
+
Apropos - Mia, Mike, Ray, Eric chat plus special guest Martin Kavalar
+
+
+
+Blogs, discussions, tutorials
+
+
+
+
+-
+
-
+
Open and Closed Systems with Clojure - Daniel Gregoire
+
+ -
+
What is simplicity in programming and why does it matter? - Jakub Holý
+
+ -
+
Counterfactuals are not Causality - Michael Nygard - not about Clojure but worth a read!
+
+ -
+
How I’m learning Clojure - Rob Haisfield
+
+ -
+
Clojure metadata - Roman Ostash
+
+ -
+
Data notation in Clojure - Roman Ostash
+
+ -
+
Specific vs. general: Which is better? - Jakub Holý
+
+
+
+Libraries
+
+
+
+
+Some interesting library updates and posts this week:
+
+
+-
+
-
+
spock 0.1.1 - a Prolog in Clojure
+
+ -
+
recife 0.3.0 - model checker library in Clojure
+
+ -
+
datascript 1.2.1 - immutable in-memory database and Datalog query engine
+
+ -
+
sparql-endpoint 0.1.2 - utilities for interfacing with SPARQL 1.1 endpoints
+
+ -
+
pulumi-cljs - ClojureScript wrapper for Pulumi’s infrastructure as code Node API
+
+ -
+
c4k-keycloak - k8s deployment for keycloak
+
+ -
+
clj-statecharts 0.1.0 - State Machine and StateCharts for Clojure(Script)
+
+ -
+
clojure-lsp 2021.06.24-14.24.11 - Language Server (LSP) for Clojure
+
+ -
+
tick 0.4.32 - Time as a value
+
+ -
+
aws-api 0.8.515 - programmatic access to AWS services from Clojure
+
+
+
+Tools
+
+
+
+
+-
+
-
+
Clojure LibHunt - find Clojure open source projects!
+
+ -
+
syncretism - options search engine based on Yahoo! Finance market data
+
+ -
+
mastodon-bot - bot for mirroring Twitter/Tumblr accounts and RSS feeds on Mastodon
+
+
+
+Fun and Games
+
+
+
+
+Chris Ford did a live coding performance (on keytar!) - see the code
+
+
+
+ Throwback Friday (I know, I’m doing it wrong)
+
+
+
+
+In this recurring segment, we harken back to talks from an older time of yore. This week, we’re featuring:
+
+
+-
+
-
+
How to Think about Parallel Programming: Not! by Guy L. Steele Jr from Strange Loop 2010 - it’s a decade+ old but still worth watching for how we think about what languages should provide, and a particular inspiration to the later design of Clojure reducers
+
+ -
+
Advent of Code 2020, Day 17 by Zach Tellman - a wonderful example of how to work in Clojure. write code in your editor, eval small exprs to your REPL, building iteratively up to a final solution
+
+
+
+
+
+ Run online campus events with your favorite tools at no cost with the new GitHub Virtual Event Kit
+The GitHub Blog 24 06 2021
+
+
+ ¿Estuvo implicada una estrella de quarks en GW190814?
+NeoFronteras 24 06 2021
+
+
+ +Clojure Engineer (Remote) +
++Brave Clojure Jobs + 24 06 2021
+Clojure Engineer (Remote)
Composer | US & Canada
remote
Build, test, and deploy automated trading strategies without any code!
$130000 - $200000
Build the infrastructure powering our automated portfolio management platform!
Composer is a no-code platform for automated investment management. Composer allows you to build, test, deploy, and manage automated investing strategies - all without writing a line of code.
As an early backend engineer at Composer you will:
+-
+
- Be responsible for designing and building critical pieces of our infrastructure +
- Work closely with the executive team to guide our decisions regarding technical architecture +
Projects you will work on:
+-
+
- Creating a language that clients can use to define any conceivable trading strategy ("strategies as data") +
- Determining the best way to collaborate on, share, and/or monetize strategies +
- Allowing clients to develop custom logic to further personalize their strategies +
- See here for more ideas! +
We're looking for someone who:
+-
+
- Loves Clojure! (Clojurescript a bonus) +
- Has familiarity with cloud platforms (We use GCP) +
- Will be a technical thought leader within the company +
- Understands database design +
- Makes educated decisions when faced with uncertainty +
What's it like to work at Composer?
+-
+
- We believe diverse perspectives are necessary if we aim to disrupt finance. To that end, we are an equal opportunity employer and welcome a wide array of backgrounds, experiences, and abilities. +
- We believe the simplest solution is most likely the best one +
- We encourage self-improvement and learning new skills +
- We are venture-backed by top investors +
- We are 100% remote :) +
- We offer generous equity! +
- Our Values +
+
+ Escasas perspectivas a la vida compleja en exoplanetas
+NeoFronteras 24 06 2021
+
+
+ Nos podrían estar detectando
+NeoFronteras 24 06 2021
+
+
+ I complete. You?
+Manuel Uberti 24 06 2021
+Tracking the Emacs development by building its master branch may not be a smooth +experience for everyone, but for the average enthusiast is the perfect way to +see their favourite tool evolve, trying experimental things, and reporting back +to the core developers to help them. Sure, one has to deal with occasional build +failures, but with Git at one’s service it’s always easy to reset to a working +commit and find happiness again.
+ +Recently a shiny new mode has been implemented on master:
+icomplete-vertical-mode. Now, if you had the chance to read this blog in the
+past you know that when it comes to candidate completion I am a gangsta jumping
+back and forth among packages with excessive self-satisfaction. But you should
+also already know that I like to use as many Emacs built-ins as possible. Hence,
+I could not wait to give icomplete-vertical-mode a try.
Turning it on is trivial:
+ +(icomplete-mode +1)
+(add-hook 'icomplete-mode-hook #'icomplete-vertical-mode)
+Since other completion systems have spoiled me, I prefer scrolling over the
+rotating behaviour of the standard icomplete:
(setq icomplete-scroll t)
+Furthermore, I always want to see the candidate list:
+ +(setq icomplete-show-matches-on-no-input t)
+This is pretty much it. I use icomplete-fido-backward-updir to move up one
+directory and I have exit-minibuffer bound to C-j for convenience.
I have been using icomplete-vertical-mode daily for a while now and everything
+has been working as expected. For the record, this mode works seamlessly with
+your favourite completion-styles settings, so moving from, say, Vertico to
+icomplete-vertical-mode is simple and easy.
+
+ I complete. You?
+Manuel Uberti 24 06 2021
+Tracking the Emacs development by building its master branch may not be a smooth +experience for everyone, but for the average enthusiast is the perfect way to +see their favourite tool evolve, trying experimental things, and reporting back +to the core developers to help them. Sure, one has to deal with occasional build +failures, but with Git at one’s service it’s always easy to reset to a working +commit and find happiness again.
+ +Recently a shiny new mode has been implemented on master:
+icomplete-vertical-mode. Now, if you had the chance to read this blog in the
+past you know that when it comes to candidate completion I am a gangsta jumping
+back and forth among packages with excessive self-satisfaction. But you should
+also already know that I like to use as many Emacs built-ins as possible. Hence,
+I could not wait to give icomplete-vertical-mode a try.
Turning it on is trivial:
+ +(icomplete-mode +1)
+(add-hook 'icomplete-mode-hook #'icomplete-vertical-mode)
+Since other completion systems have spoiled me, I prefer scrolling over the
+rotating behaviour of the standard icomplete:
(setq icomplete-scroll t)
+Furthermore, I always want to see the candidate list:
+ +(setq icomplete-show-matches-on-no-input t)
+This is pretty much it. I use icomplete-fido-backward-updir to move up one
+directory and I have exit-minibuffer bound to C-j for convenience.
I have been using icomplete-vertical-mode daily for a while now and everything
+has been working as expected. For the record, this mode works seamlessly with
+your favourite completion-styles settings, so moving from, say, Vertico to
+icomplete-vertical-mode is simple and easy.
+
+
+
+ Introducing the new GitHub Issues
+The GitHub Blog 23 06 2021
+
+
+ Navegador Brave publica nuevo buscador basado en la privacidad
+Blog elhacker.NET 23 06 2021
+
+
+ 666
+Extra Ordinary 23 06 2021
+
+
+ Disponible nueva versión navegador Tor corrige errores rastreo mediante aplicaciones instaladas
+Blog elhacker.NET 23 06 2021
+
+
+ Ransomware DarkRadiation afecta a Linux y contenedores Docker
+Blog elhacker.NET 22 06 2021
+
+
+
+
+ A framework for building Open Graph images
+The GitHub Blog 22 06 2021
+
+
+ Sobre la fluctuación en la población de vanesas
+NeoFronteras 22 06 2021
+
+
+ Superenfriamiento de un cuerpo macroscópico
+NeoFronteras 22 06 2021
+
+
+ Valida tu modelo de datos con FluentValidation en C#
+En Mi Local Funciona 22 06 2021
+
+
+ Custom Scrollbars In CSS
+Ahmad Shadeed Blog 22 06 2021
+
+
+
+
+ Custom "cops" for RuboCop: an emergency service for your Ruby code
+Martian Chronicles, Evil Martians’ team blog 22 06 2021
+
+
+
+
+ GitHub Packages Container registry is generally available
+The GitHub Blog 21 06 2021
+
+
+
+
+ 5 errores de SEO que perjudican tu blog
+No sin mis cookies 21 06 2021
+Los blogs están a la orden del día. Cada vez son más las personas que ganan dinero con sus propios dominios, apostando por una idea de negocio innovadora. Si tú también has optado por la creación de un blog, estoy seguro de que sabes de lo que te hablo. Pero entonces ocurre el primer desencuentro: ... Read more
+The post 5 errores de SEO que perjudican tu blog appeared first on No sin mis cookies.
+ +
+
+ La plataforma en la nube de la OTAN ha sido hackeada
+Blog elhacker.NET 21 06 2021
+
+
+
+
+ Pandemic Progress
+Stratechery by Ben Thompson 21 06 2021
+
+
+ Guía NSA sobre la protección de las comunicaciones unificadas y los sistemas de voz y video sobre IP
+Blog elhacker.NET 21 06 2021
+
+
+
+
+ Accountability
+Work Chronicles 20 06 2021
+The post Accountability appeared first on Work Chronicles.
+ +
+
+ Paraceratherium linxiaense
+NeoFronteras 20 06 2021
+
+
+ Actualizaciones de seguridad para Microsoft y Google Chrome
+Blog elhacker.NET 19 06 2021
+
+
+
+
+ Honest Review
+Work Chronicles 19 06 2021
+The post Honest Review appeared first on Work Chronicles.
+ +
+
+
+
+ Estado de Drupal con Borja Vicente de escueladrupal.com
+República Web 19 06 2021
+Vuelve Drupal al podcast y para esta ocasión contamos con la compañía del desarrollador web especializado en Drupal Borja Vicente, creador de la web y el canal escueladrupal.com Invitamos a Borja para que nos cuente muchas cosas sobre su proyecto y el estado actual de Drupal. Borja desarrolla en backend con Drupal desde hace más de 10 años y actualmente su labor profesional se desarrolla con Drupal, aunque suele también experimentar con Symfony, Laravel, Django y también Ruby on Rails. Además Borja también tiene publicado cursos especializados en Drupal a través de la plataforma Udemy.
+ + + +Con Borja tratamos muchas cuestiones relacionados con Drupal y su proyecto de contenidos:
+ + + +- Evolución de Drupal hasta su última versión
- Comunidad Drupal a nivel internacional y nacional
- Proyectos o casos de uso ideales para desarrollar con Drupal 9?
- Recomendaciones esenciales para gestionar una instalación de Drupal
- Motivaciones para crear Escuela Drupal y lo que gustaría conseguir.
- Entorno de desarrollo usado para Drupal.
- Módulos que más te ayudan al desarrollo web con Drupal.
Muy agradecidos a Manu por propiciar en Twitter este episodio sobre Drupal con Borja.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Malware sin nombre fue capaz de robar 26 millones de credenciales de 3,25 millones de ordenadores
+Blog elhacker.NET 19 06 2021
+
+
+ +Senior Software Engineer (Clojure) +
++Brave Clojure Jobs + 19 06 2021
+Senior Software Engineer (Clojure)
Compute Software | USA and Canada
remote
Startup that helps enterprises to run optimally on the public cloud.
About Us
With ever-growing workloads on the cloud, companies face significant challenges in managing productivity and spending, and maximizing impact to their businesses. Compute Software is addressing a huge market opportunity to help companies make good business decisions and run optimally on the public cloud. We're building a powerful platform to give customers the tools they need to gain transparency, optimize their usage, and execute change across their organizations.
We're a small, distributed team, currently spanning California to Quebec, and we offer early stage market-rate compensation (including equity), health and dental insurance, and 401K benefits. You'll be joining a venture capital-backed, distributed team with ambitious goals, and you will have the ability to make a direct and lasting impact on the team and product.
Your Role
Be one of the earliest employees and join our early-stage engineering team as a Senior Software Engineer. You will be essential in shaping the features and functionality of our SaaS platform, culture and processes.
You'll spend your day enveloped in Clojure. The backend is written in Clojure and driven by data in Datomic and InfluxDB. The frontend is written in ClojureScript using re-frame and communicates with the backend using Pathom. We deploy to AWS Fargate and Datomic Ions.
For product development, we follow Shape Up. We use Notion, Slack, and ClubHouse.
What will you do at Compute Software?
+-
+
- Write Clojure and ClojureScript. +
- Design, build, and deploy features and bug fixes across the entire stack. +
- Become an expert in all the nuances of the various cloud platforms like Amazon Web Services, Google Cloud, and Microsoft Azure. +
- Provide product feedback and evaluate trade-offs to impact product direction. +
- Debug production problems. +
What We're Looking For Passion - you are excited about the large, high-growth cloud computing market and figuring out how to help customers, who are using cloud computing solutions today. You are excited by being one of the earliest employees and getting to work with a small team.
Engineering experience - you're a Clojure practitioner with 6+ years of professional experience. You know what it takes to create large-scale b2b software. You can create effective and simple solutions to problems quickly, and communicate your ideas clearly to your teammates.
Product-minded - you love building products and you care about the details of creating a great user experience. You have an interest in how users will use our platform and the impact we will have on them. You can balance your consideration of the product and user requirements with technical complexity and implementation details to make appropriate decisions when things are unclear.
Effective communication - you're great at communicating. If something is unclear you reach out and ask questions. You're comfortable owning, communicating and presenting information on specific projects or initiatives, both in writing and in person.
Organizational and project management - you are highly organized and able to self-manage projects in a fast-moving company. You are able to take high level goals and break them down into achievable steps.
+
+ Updated Debian 10: 10.10 released
+Debian News 19 06 2021
+buster). +This point release mainly adds corrections for security issues, +along with a few adjustments for serious problems. Security advisories +have already been published separately and are referenced where available. + +
+
+
+
+ Turn on your cameras
+Work Chronicles 18 06 2021
+The post Turn on your cameras appeared first on Work Chronicles.
+ +
+
+ Clojure Deref (June 18, 2021)
+Clojure News 18 06 2021
+
+
+
+
+
+
+Welcome to the Clojure Deref! This is a periodic link/news roundup for the Clojure ecosystem. (@ClojureDeref RSS)
+
+
+Highlights
+
+
+
+
+-
+
-
+
HOPL IV (History of Programming Languages) at PLDI 2021 is happening on Monday and Tuesday and includes a talk from Rich Hickey about the History of Clojure paper. Registration is still available and the conference is online and features many other fine language developers!
+
+ -
+
The results are out from the JVM Ecosystem Report 2021 and Clojure continues to make a strong showing as one of the most popular JVM languages (other than Java), rising from 2.9% last year to 8.4% this year. Lots of other interesting tidbits in there as well.
+
+
+
+Sponsorship Spotlight
+
+
+
+
+Lately Christophe Grand and Baptiste Dupuch have been teasing their work on a new ClojureDart runtime with Flutter support. You can support their work on GitHub: cgrand dupuchba. Nubank (users of both Clojure and Flutter) are now supporting both!
+
+
+Podcasts and videos
+
+
+
+
+-
+
-
+
LispCast - Eric Normand talks about stratified design
+
+ -
+
defn - Vijay Kiran and Ray McDermott interview Paula Gearon
+
+ -
+
REPL-driven development - demo from Jakub Holý
+
+ - + + +
+
+Blogs, discussions, tutorials
+
+
+
+
+-
+
-
+
Clojure Transducers - Joanne Cheng explains transducers
+
+ -
+
Clojure’s Destructuring - Daniel Gregoire dives into destructuring
+
+ -
+
Better performance with Java arrays in Clojure - Daw-Ran Liou on using Java arrays in Clojure
+
+ -
+
Backpressure - Kenny Tilton talks about core.async and ETL
+
+ -
+
Fun of clojure - wrap some code around data - @Sharas_ on the data ethos of Clojure
+
+ -
+
Lambda Island is Changing - Arne Brasseur and his merry band of Clojurists at Gaiwan are changing directions a bit
+
+ -
+
Should you adopt Clojure at your company? - Shivek Khurana, TLDR: yes! :)
+
+
+
+Libraries and Tools
+
+
+
+
+Some interesting library updates and posts this week:
+
+
+-
+
-
+
ordnungsamt - a tool for running ad-hoc migrations over a code repository
+
+ -
+
clj-github - a library for working with the GitHub developer API
+
+ -
+
umschreiben-clj - extensions to rewrite-clj
+
+ -
+
Copilot - Tony Kay teased a new upcoming code analysis tool for Clojure and ClojureScript
+
+ -
+
scittle - Michiel Borkent did the first release of the SCI interpreter for use in script tags
+
+ -
+
clojure-lsp - Eric Dallo released a new version with enhanced path support for deps.edn projects
+
+ -
+
holy-lambda - Karol Wójcik released a new version
+
+ -
+
honeysql - Sean Corfield added :distinct syntax and some other features and fixes
+
+ -
+
Fulcro - Tony Kay released 3.5.0-RC1 with more support for non-React apps
+
+ - + + +
-
+
refl - Michiel Borkent released a new example project to clean up reflection configs for GraalVM for Clojure projects
+
+
+
+Fun and Games
+
+
+
+
+-
+
-
+
Fidenza - Tyler Hobbs has a long history of doing interesting generative art with Clojure and he has published a rundown of his newest generative algorithm. Not explicitly Clojure but fascinating to read.
+
+ -
+
ClojureScript racing game - Ertuğrul Çetin published this game this week
+
+
+
+
+ Throwback Friday (I know, I’m doing it wrong)
+
+
+
+
+In this recurring segment, we harken back to a talk from an older time to a favorite talk of yore. This week, we’re featuring:
+
+
+-
+
-
+
Why is a Monad Like a Writing Desk? by Carin Meier from Clojure/West 2012
+
+
+
+In this lovely story from 2012, Carin Meier talks about monads through the lens of Clojure and Alice in Wonderland.
+
+
+ Contaminación luminosa e insectos
+NeoFronteras 17 06 2021
+
+
+
+
+ Virtual Meetings
+Work Chronicles 16 06 2021
+The post Virtual Meetings appeared first on Work Chronicles.
+ +
+
+
+
+ GitHub Desktop 2.9 includes squashing, reordering, amending, and more!
+The GitHub Blog 16 06 2021
+
+ 
+
+
+ Dark Mode for HTML Form Controls
+Microsoft Edge Blog 16 06 2021
+If you build a web application, chances are good that you’ve received user requests for dark mode support in the past couple of years. While some users may simply prefer the aesthetics of dark UI, others may find that dark mode helps ease eye strai
+The post Dark Mode for HTML Form Controls appeared first on Microsoft Edge Blog.
+ +
+
+ 665
+Extra Ordinary 16 06 2021
+
+
+
+
+ AnyCable Goes Pro: Fast WebSockets for Ruby, at scale
+Martian Chronicles, Evil Martians’ team blog 16 06 2021
+
+
+ Update to the FSF and GNU's plan to move IRC channels to Libera.Chat
+FSF News 15 06 2021
+
+
+
+
+ Nos vamos al Congreso esLibre 2021
+República Web 15 06 2021
+En este episodio Andros Fenollosa y David Vaquero hablan sobre la edición del Congreso esLibre 2021, una nueva edición en formato virtual, sobre tecnologías libres enfocadas a compartir conocimiento. Esta edición contará con la participación de una charla de Andros sobre su sistema Glosa de comentarios para sitios estáticos y un taller de David sobre su contenedor Docker para Drupal.
+ + + +En el episodio también se habla sobre la participación de algunas personas que han pasado por el podcast como Eduardo Collado, Sergio López, Lorenzo Carbonell, Rubén Ojeda o Jesús Amieiro. Como ha comentado David Vaquero con anterioridad, en esta edición se ha apostado por involucrar a la comunidad en español de podcasts tecnológicos, para lograr dar mayor difusión a los contenidos del Congreso.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ Improving contrast in Microsoft Edge DevTools: A bugfix case study
+Microsoft Edge Blog 15 06 2021
+Creating accessible products means most of all being aware of the usability issues your designs and code can cause. When creating new products, Microsoft follows a strict workflow of accessibility reviews of designs, code reviews and mandatory audits
+The post Improving contrast in Microsoft Edge DevTools: A bugfix case study appeared first on Microsoft Edge Blog.
+ +
+
+
+
+ The Cicilline Salvo
+Stratechery by Ben Thompson 15 06 2021
+
+ 
+
+
+ Measure Twice, Cut Once
+MonkeyUser 15 06 2021
+
+
+ The Importance of Learning CSS
+Josh Comeau's blog 13 06 2021
+
+
+ FSF and GNU move official IRC channels to Libera.Chat network
+FSF News 11 06 2021
+
+
+ Clojure Deref (June 11, 2021)
+Clojure News 11 06 2021
+
+
+
+
+
+
+Welcome to the Clojure Deref! This is a periodic link/news roundup for the Clojure ecosystem. (RSS feed)
+
+
+Highlights
+
+
+
+
+This week Nubank announced a new $750M investment, led by $500M from Berkshire Hathaway at a $30B valuation. Nubank is the largest user of Clojure and Datomic in the world and a great example of the benefits of Clojure’s approach to managing complexity at scale.
+
+
+Chris Nuernberger presented a great talk this week for London Clojurians about his work on high performance data processing with the dtype-next and tech.ml.dataset libraries.
+
+
+The ClojureD conference last weekend was great with lots of interesting Clojure (and some non-Clojure) talks! Keep an eye out for videos soon.
+
+
+Podcasts
+
+
+
+
+We have a bumper crop of Clojure-related podcast episodes this week, put these in your ears…
+
+
+-
+
-
+
Cognicast - Christian Romney interviews Jarrod Taylor from the Datomic team
+
+ -
+
Get Smarter and Make Stuff - Craig Andera interviews Michael Fogus from the Clojure core team
+
+ -
+
Lost in Lambduhhs - Jordan Miller interviews Alex Miller from the Clojure core team
+
+ -
+
ClojureScript Podcast - Jacek Schae interviews Tommi Reiman about Malli
+
+ -
+
defn - Vijay Kiran and Ray McDermott interview Chris Badahdah about Portal
+
+
+
+Libraries and Databases
+
+
+
+
+Some interesting library updates and posts this week:
+
+
+-
+
-
+
Mirabelle - 0.1.0 of this stream processing tool inspired by Riemann - check out the docs and a use case
+
+ -
+
sicmutils - Sam Ritchie released version 0.19.0 of this math and physics based library (based on the books by Sussman and Wisdom)
+
+ -
+
Cybermonday - Kiran Shila releases the first release of this Clojure data interface to Markdown (like Hiccup for Markdown)
+
+ -
+
HoneyEQL - Tamizhvendan S introduced 0.1.0-alpha36 for EQL queries to relational databases
+
+ -
+
Expectations - Sean Corfield released 2.0.0-alpha2 of this clojure.test-compatible implementation of Expectations
+
+ -
+
Snoop - Luis Thiam-Nye announced the initial release of a library for runtime function validation using Malli
+
+ -
+
OSS Clojure DBs - a summary and comparison of open-source Clojure databases (but don’t forget Datomic! :)
+
+
+
+Blogs, discussions, tutorials
+
+
+
+
+-
+
-
+
Tetris in ClojureScript - by Shaun Lebron
+
+ -
+
Apache Kafka & Ziggurat - Ziggurat is an event stream processing tool written in Clojure and this article shows how to use it to consume events from Kafka
+
+ -
+
Why are Clojure beginners just like vegans searching for good cheese? - on Lambda Island
+
+ -
+
Ping CRM on Clojure - a demo of implementing Ping CRM on Clojure+ClojureScript
+
+ -
+
Organizing Clojure code - a discussion from Clojureverse
+
+ -
+
An Animated Introduction to Clojure - by Mark Mahoney
+
+
+
+
+ Throwback Friday (I know, I’m doing it wrong)
+
+
+
+
+In this recurring segment, we harken back to a talk from an older time to a favorite talk of yore. This week, we’re featuring:
+
+
+-
+
-
+
Clojure: Programming with Hand Tools by Tim Ewald
+
+
+
+Is it about woodworking? Is it about Clojure? Is it about how to work? Yes.
+
+
+
+
+ Blacktocats turn five
+The GitHub Blog 10 06 2021
+
+
+
+
+ What’s new from GitHub Changelog? May 2021 Recap
+The GitHub Blog 10 06 2021
+
+
+
+
+ Privilege escalation with polkit: How to get root on Linux with a seven-year-old bug
+The GitHub Blog 10 06 2021
+
+
+ Becoming a Software Developer Without a CS Degree
+Josh Comeau's blog 10 06 2021
+
+
+ Announcing “use-sound”, a React Hook for Sound Effects
+Josh Comeau's blog 10 06 2021
+
+
+ Boop!
+Josh Comeau's blog 10 06 2021
+
+
+ Let's Bring Spacer GIFs Back!
+Josh Comeau's blog 10 06 2021
+
+
+ Let's Learn About Aspect Ratio In CSS
+Ahmad Shadeed Blog 10 06 2021
+
+
+ The Rules of Margin Collapse
+Josh Comeau's blog 09 06 2021
+
+
+ An Interactive Guide to CSS Transitions
+Josh Comeau's blog 09 06 2021
+
+
+ What the heck, z-index??
+Josh Comeau's blog 09 06 2021
+
+
+ Building a Magical 3D Button
+Josh Comeau's blog 09 06 2021
+
+
+ How I Built My Blog
+Josh Comeau's blog 09 06 2021
+
+
+ 664
+Extra Ordinary 09 06 2021
+
+
+ Resolviendo side-effects en React
+En Mi Local Funciona 09 06 2021
+
+
+
+
+ Integrated Apple and App Store Risk
+Stratechery by Ben Thompson 08 06 2021
+
+ 
+
+
+ Exposed
+MonkeyUser 08 06 2021
+
+
+ +Data Platform Engineer +
++Brave Clojure Jobs + 07 06 2021
+Data Platform Engineer
Analytical Flavor Systems | Remote/NY,NY
remote
Advancing sensory science and reaching new taste buds
$120000 - $180000
Description
Analytical Flavor Systems is a venture-backed startup that models human sensory perception of flavor, aroma, and texture using proprietary machine learning in order to predict consumer preference of food and beverage products. The work we do allows our clients in the food & beverage industry to ask and answer questions about:
+-
+
- their competitive landscape ("what do people like and dislike about my competitors' products?") +
- optimizing existing products ("how can I make this cookie taste better?") +
- novel flavor combinations for new product development ("would people like it if I combined matcha and strawberry in yogurt?") +
Our data science capabilities are evolving from report generation to a data platform. That's where you come in.
The work expected of a data platform engineer at Analytical Flavor Systems covers several major areas:
+-
+
- Building out a data model on Datomic to capture the information generated by our day-to-day data processing tasks in an immutable and readily queryable data store. +
- Creating a data platform application layer to serve the needs of our data science team, our web console and our mobile data collection app. +
- Rewriting existing data science code for execution in a distributed rather than single-machine environment. +
- Maintaining and enhancing batch processing jobs to make them faster, more reliable, and more observable. +
- Refactoring an existing codebase to be more modular: separating data transformations, modeling, and prediction steps into discrete functions with well-understood inputs and outputs, while testing for regressions in predictive capabilities. +
Depending on your background and areas of expertise, your day-to-day work may focus more on one of these areas than others, but you should be able to keep the big picture in mind, and understand how the changes you make to one part of our system affect the whole. Your work will improve our ability to execute this code reliably, and replicate previous results. This work will also help us observe and capture the outputs of the analytical operations we perform so we get better insight into the state of the systems built atop our data science code.
You will be expected to become comfortable working in both Clojure and R, though no prior experience in R is required. This role offers you the chance to help develop the language of our research domain, which may help us identify potential new avenues of theoretical research in human sensory perception.
We are only considering candidates with USA work authorization or work visa (including OPT). AFS can sponsor H1-B renewals or transfers.
Requirements
Candidates should have at least 4 years of total programming experience, with at least 1 year of work in either a data engineering context or in building backend systems. Experience with Clojure or other functional programming languages is a plus, but not a requirement. Functional programming is as much a style and idiom of development as it is a family of languages. Candidates that have experience building modular systems that put data front and center, regardless of the implementation language, should be attracted to this role.
Candidates with experience supporting the work of researchers and data scientists are also strongly encouraged to apply. Have you made an analytical method production-ready after reading through someone else's prototype code? Are you interested in interoperability between R and Clojure? Have you helped deploy and monitor models in production? Experience with these questions gives you a good understanding of the requirements and scope of the systems we build.
The company is roughly 15 people total, so candidates will be working closely with other teams and areas of the business. Good communication skills, especially across varying levels of technical depth and skill, are preferred.
A good candidate should have experience in at least two of the following areas:
+-
+
- Data science and analytics: you have enabled more powerful access to data for both technical and non-technical stakeholders. You understand how to support and enhance systems based on machine learning, and aren't afraid of diving in to build a more efficient implementation of an algorithm than one provided by a library. +
- Data modeling: you have, either on your own or as part of a team, designed or extended a relational database schema to support application and business requirements. +
- System design and maintenance: you know how to build and extend existing systems to make them more observable, fault-tolerant, and performant. You can ssh into a remote box to contextualize a problem that doesn't have an obvious cause. +
- Automated QA and testing: you know what the invariant properties of both individual functions and system components are, and can represent those properties in code. +
Benefits
+-
+
- Competitive salary +
- Standard benefits package (health insurance/vision/dental + 401k) +
- Equity stake (Restricted Stock Units with 4-year annual vesting schedule) +
- Remote-friendly (who isn't these days?). While we do plan on an eventual return to our office space in Manhattan once it's safe, immediate relocation to the NYC area is not an expectation of this role. +
- That said, if you do end up in our NYC office you'll be able to join regular in-person tasting panels to get hands-on experience with the sensory data collection methods we use. +
- Unlimited vacation policy +
- Professional development budget +
+
+ Cómo instalar Git en Centos 7
+ochobitshacenunbyte 07 06 2021
+Aprendemos a instalar Git en Centos 7. Aunque este programa de control de versiones ya viene en los repositorios de Centos o de Red Hat, si utilizamos la distribución del sombrero rojo, lo cierto...
+La entrada Cómo instalar Git en Centos 7 se publicó primero en ochobitshacenunbyte.
+ +
+ 
+
+
+ Porqué cambiamos de trabajo en tecnología
+República Web 05 06 2021
+A diferencia de otros sectores, los profesionales de las habilidades relacionadas con la tecnología, suelen contar con más opciones y oportunidades laborales. Por si fuera poco ese mercado de programadores, desarrolladores y consultores tecnológicos, opta desde hace tiempo, a trabajos en remoto y a condiciones laborales que durante la pandemia han experimentado un notable auge.
+ + + +Los developers están por tanto en una especie de burbuja laboral, donde a la hora de valorar un puesto de trabajo o un cambio, existen diferentes motivaciones que merece la pena discutir.
+ + + +En este episodio queremos hablar sobre los motivos que tienen los developers a la hora de afrontar cambios laborales y el punto de vista que a menudo tienen con respecto a su vida profesional. Aunque en muchas ocasiones esas motivaciones coincidan con otros perfiles profesionales, creemos muy interesante poder contar las experiencias o casos que hayamos visto o vivido.
+ + + ++El próximo episodio del podcast irá sobre los motivos que llevan a los «developers» a cambiar de trabajo. ¿Qué te motiva **principalmente** para valorar un cambio de trabajo?
— Podcast República Web (@republicawebes) June 4, 2021
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Clojure Deref (June 4, 2021)
+Clojure News 04 06 2021
+
+
+
+
+
+
+Welcome to the Clojure Deref! This is a new periodic (thinking bi-weekly) link/news roundup for the Clojure ecosystem. We’ll be including links to Clojure articles, Clojure libraries, and when relevant, what’s happening in the Clojure core team.
+
+
+Highlights
+
+
+
+
+ClojureScript turns 10 this week! Happy birthday ClojureScript! :cake: We mark this from the first commit by Rich Hickey in the repo. Several thousand commits later things are still going strong and David Nolen and Mike Fikes continue to lead the project. ClojureScript recently released version 1.10.866.
+
+
+The StackOverflow developer’s survey for 2021 just opened. Last year they removed Clojure from the survey because they were scared we were growing too powerful (I assume). But this year’s survey includes Clojure as an option again, so let them know you’re out there! (It also seems a lot shorter this year.)
+
+
+The :clojureD Conference is just hours away! Ticket sales have ended but presumably talks will be made available afterwards. If you’re going, we’ll see you there!
+
+
+Experience reports
+
+
+
+
+This week we saw several interesting Clojure experience reports worth mentioning:
+
+
+-
+
-
+
Red Planet Labs gave an overview of their codebase and some of the techniques they use pervasively - using Schema, monorepo, Specter for polymorphic data, Component, with-redefs for testing, macros and more.
+
+ -
+
Jakub Holý at Telia talked about the importance of interactive development with Clojure.
+
+ -
+
Crossbeam did a talk at Philly Tech Week about why they bet on Clojure and their experience with hiring.
+
+ -
+
Shivek Khurana talked about how to find a job using Clojure. There are now many companies using and hiring for Clojure, although sometimes it’s challenging to find a Clojure job that is a good match for your location and/or experience - these are some great tips!
+
+
+
+Libraries
+
+
+
+
+Some interesting library updates and posts this week:
+
+
+-
+
-
+
Asami - Paula Gearon wrote a nice overivew of querying graph dbs
+
+ -
+
Joe Littlejohn at Juxt wrote an overview of the Clojure JSON ecosystem covering many popular libraries and their tradeoffs
+
+ -
+
odoyle-rules - Zach Oakes added a new section on defining rules dynamically
+
+ -
+
Reveal - Vlad wrote about viewing Vega charts in Reveal
+
+ -
+
Pathom - Wilker Lucio gives some updates on many features
+
+
+
+Art
+
+
+
+
+-
+
-
+
As always Jack Rusher has been up to making beautiful art with Clojure, in particular exploring 3D rendered attractors like the Golden Aizwa Attractor (the Clojure code) and Three-Scroll Uunified Attractor, and one made in bone. Hit his feed for lots more cool projects, often made with Clojure.
+
+
+
+
+ Feedback
+
+
+
+
+You can find future episodes on the RSS feed for this blog. Should it be an email newsletter too?
+
+
+Let us know!
+
+ 
+
+
+ Loading Weekend
+MonkeyUser 04 06 2021
+
+
+
+
+ Passport
+Stratechery by Ben Thompson 03 06 2021
+
+
+ Introducing the Open Source Insights Project
+Google Open Source Blog 03 06 2021
+
+
+ +Senior Software Developer +
++Brave Clojure Jobs + 03 06 2021
+Senior Software Developer
LegalMate | Toronto || Anywhere
remote
We are bringing progressive and modern financial services to the legal world.
$110000 - $140000
About LegalMate
Our mission is make access to justice affordable. In North America, almost $400 billion dollars is spent every year on legal services, yet 86% of of civil legal problems faced by low-income individuals receive either inadequate or no legal help at all. The legal system is intended to benefit us all, not just the top 10% of income earners.
We are bringing progressive and modern financial services to the legal world, opening the door for more people to access legal services and seek justice.
+-
+
- We're VC-backed and well capitalized +
- We have paying customers and exciting MoM growth +
- Our founding team has an exceptional track record +
- ($2.5 billion in shareholder value created in previous 3 ventures) +
- Our first product is "Buy Now Pay Later" for legal services: think Affirm for lawyers +
Role & Responsibilities
This is the first full-time hire on our engineering team, apart from our CTO. Consequently, candidates should expect a high degree of trust and autonomy. We intend to do great work together over the long-term, and we insist that anybody joining LegalMate at this stage is ready to grow with the company and take on more responsibility as we scale.
We are a Clojure shop and are looking to work with engineers eager to apply functional programming concepts. We are happy to train folks up on Clojure!
+-
+
- Write production-grade Clojure and ClojureScript +
- Review code, and provide constructive and useful feedback +
- Create and collaborate on technical designs, document them +
- Coach and mentor junior Clojurians in the making +
-
+
- Introducing new developers to Clojure is a critical to our strategy +
-
+
- Elevate the test-ability and re-usability of existing code +
- Help evaluate and hire additional engineering team members (in the future) +
Recommended Experience
These are provided for you to understand the relative skill and experience level of the candidates we're seeking. If you don't meet or exceed these 100%, that's OK! Please consider applying regardless.
+-
+
- 5+ yrs of professional software development experience (Clojure or otherwise) +
- 2+ yrs of Clojure development experience (professional or hobby) +
- Previous experience working on small teams that scaled up +
- You have a track record of leading successful projects +
- You can give concrete examples of when you've received some hard feedback, and when you've had to deliver some hard feedback too +
About You
This role is ideal for a senior developer who's comfortable with Clojure (or wants to learn), and who wants to participate in building and growing a world-class engineering team and company.
+-
+
- You're more motivated to help humans than you are to solve coding puzzles +
- You're comfortable with Clojure idioms (or want to learn) and functional programming concepts +
- The idea of working with functional programming (Clojure) full-time is exciting and motivating +
- You use data to help make decisions and inform designs +
- You know how to manage your energy and time +
Nice-to-have Qualities You Might Have
+-
+
- You have prior experience in financial technology, or legal technology +
- To you, working on legal financial tech doesn't sound boring: it sounds awesome +
- You're ready to quit programming if you don't get to use functional programming in you're next position +
+
+
+
+ Premium design: Building a mobile app for Loewe
+Martian Chronicles, Evil Martians’ team blog 03 06 2021
+
+
+ +Remote Clojure Developer +
++Brave Clojure Jobs + 02 06 2021
+Remote Clojure Developer
Insight Global | US Based
remote
$135000 - $165000
Do you like solving interesting problems? Are you passionate about working in one of the fastest growing product lines in the cybersecurity industry? Want a competitive salary and benefits to support a stable, high-quality life outside of work? Want to work for an organization that will assist in developing your skills, talents, help you grow? Are you someone who wants flexibility and good work/life balance? Do you love working from home?
If you enjoy working with a group of creative, talented and enthusiastic individuals on problems at the intersection of data design, transparency and interaction, then please apply so we can make the connection to the decision makers for this opening.
Required: - Bachelor’s Degree - 8+ years industry experience - 2+ years’ experience in Clojure/ClojureScript
Ideal but not Required: - Advanced UI and visualization in the browser (SVG, D3, Grammar of Graphics, Tufte, Bertin) - Systems architecture (Object orientation, patterns, service orientation, reactive, functional-relational, and back again) - Logic programming (Prolog, rule systems) - Databases, inverted indexes, message queueing (Elasticsearch, Kafka, etc.) - Provisioning and configuration management (cough, cloud)
On behalf of our Client, we are seeking 3 Remote Clojure Developers to join a team of experienced Senior Clojure developers to on their Threat Response team. They use Clojure to mesh large volumes of high dimensional network, host and service information with taxonomic information about malicious software. Much of our work involves understanding and reasoning about this data, which describes the behavior of systems, and by extension, the capabilities, and intentions of these systems’ users.
Consequently, there is a lot of room to explore and apply techniques of logic programming in a practical, useful, fascinating, expansive, and evolving problem domain. The overarching goal is to provide tools that benefit the security of their end customers’ infrastructure.
The Threat Response team is distributed across North America and Europe, working from home, key characteristics included excellent verbal and written communication skills, sociability, and pride in carrying out duties and discharging responsibilities with exuberance and alacrity. The team draws on the best of agile themes and techniques of the past 30 years—continuous integration and deployment, testing, flexible collaboration with globally distributed team members via chat and video, and gradual, deliberate optimization of process in the name of keeping projects and releases flowing smoothly, in order to provide an excellent product to customers. The team is surrounded by talented QA, UX, support, documentation writers, and management - we hold ourselves to high standards.
+
+
+
+ Improving font rendering in Microsoft Edge
+Microsoft Edge Blog 02 06 2021
+Today we are excited to announce improved font rendering in the latest Canary builds of Microsoft Edge on Windows. We have improved the contrast enhancement and gamma correction to match the quality and clarity of other native Windows applications. F
+The post Improving font rendering in Microsoft Edge appeared first on Microsoft Edge Blog.
+ +
+
+ 663
+Extra Ordinary 02 06 2021
+
+
+ +Software Developer, Full Stack +
++Brave Clojure Jobs + 02 06 2021
+Software Developer, Full Stack
Pilloxa | Remote, 4h overlap with Stockholm (CET) during workday
remote
€40000 - €80000
About Pilloxa
Pilloxa is on a mission to improve patients' adherence to their treatment. Non-adherence to one's treatment plan is all too common. It is estimated to be the root cause of every 10th hospitalization and 8 deaths daily, in Sweden alone. Adherence to treatment is hard, and at Pilloxa we have set our minds to making it easier.
Pilloxa is a medtech company based in Stockholm, Sweden working with the latest technologies in an effort to improve the patient journey and quality of life for patients. We work together with patients, healthcare and pharmaceutical companies in bringing together all actors that have an impact on patients' treatment.
Role
You'll be an integral part of our small and flat team, working closely with the product and building a first-class user experience. The app is the centerpiece of Pilloxa's service and this is where you'll likely spend most of your time hacking in ClojureScript. As we grow you'll also likely be extending our still small Clojure backend and dabble with all parts of the stack.
Preferred experience
The more boxes you tick, the better.
+-
+
- Passion for making a positive impact in peoples' lives +
- 2+ years full-stack engineer +
- MSc in Computer Science or equivalent +
- Experience with Clojure +
- Experience with React Native +
- Experience with reagent/re-frame +
- Startup experience +
Process
+-
+
- Call with CTO +
- Call with Co-founder +
- Technical assignment (max 8h) +
- Presentation of assignment +
- Call with CEO +
- Reference calls +
+
+ Phaser 3: Mi primer juego HTML5/JS (Parte 3)
+En Mi Local Funciona 02 06 2021
+
+
+
+
+ Available for preview: Automatic HTTPS helps keep your browsing more secure
+Microsoft Edge Blog 01 06 2021
+Starting with Microsoft Edge 92, users can preview the Automatic HTTPS feature, which automatically switches your connections to websites from HTTP to HTTPS.
+As you browse the web, you may notice that the Microsoft Edge address bar displays a “not
+The post Available for preview: Automatic HTTPS helps keep your browsing more secure appeared first on Microsoft Edge Blog.
+ +
+
+
+
+ May 2021 Weblog: Communities Long Gone
+The History of the Web 01 06 2021
+A look at how we can save our websites from ourselves, and the stories that keep us going.
+The post May 2021 Weblog: Communities Long Gone appeared first on The History of the Web.
+ +
+ 
+
+
+ Mejores temas de WordPress para el sitio web de una inmobiliaria
+Must Comunicación 31 05 2021
+
+
+ The Perils of Rehydration
+Josh Comeau's blog 30 05 2021
+
+
+
+
+ La evolución del Jamstack
+República Web 28 05 2021
+Dedicamos este episodio a comentar el artículo de Matt Biilmann publicado recientemente en Smashing Magazine titulado The evolution of Jamstack. Mathias Biilmann es CEO de Netlify y uno de los precursores del termino Jamstack. En este artículo Biilmann empieza rememorando su presentación en el 2016 durante la SmashingConf, donde daba a conocer los principios que sustentan la arquitectura Jamstack. Ahora en 2021 Matt quiere ofrecer una perspectiva sobre cómo están evolucionando las técnicas y las soluciones orientadas a esta arquitectura de Jamstack.
+ + + +Empezamos el episodio hablando recordando los principios del Jamstack, como son la prioridad a que el front se construya lo antes posible y que exista un sólido desacople entre el front y el back. El segundo principio del Jamstack hace referencia a la obtención de datos bajo demanda (JavaScript y APIs).
+ + + +En la segunda parte hablamos de los tres puntos que según Matt marcan la evolución del Jamstack:
+ + + +- Renderizado Persistente Distribuido o DPR.
- Actualizaciones en streaming desde la capa de datos.
- Colaboración entre desarrolladores se hace popular.
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+ 
+
+
+ Evercade VS Pre-Orders NOW OPEN
+Evercade 28 05 2021
+The Evercade VS Pre-Orders are now open! You can pre-order your Starter and Premium Packs from your preferred retailer right now. Find the link to your local retailer below, or visit the Retailers Page: AUSTRALIA PIXEL CRIB: Starter Pack – https://www.pixelcrib.com.au/collections/evercade/products/evercade-vs Premium Pack – https://www.pixelcrib.com.au/collections/evercade/products/evercade-vs-premium-pack CANADA AMAZON.CA: Starter Pack – https://www.amazon.ca/dp/B094F6GJ83 Premium Pack – https://www.amazon.ca/dp/B094F5ZGX8... View Article
+The post Evercade VS Pre-Orders NOW OPEN appeared first on Evercade.
+ +
+
+
+
+ Evercade VS – What’s in the Box?
+Evercade 27 05 2021
+The Evercade VS will be available to Pre-Order from May 28th with the release date of November 3rd 2021. The console is available in two packs: STARTER PACK The Evercade VS Starter Pack is the entry point to the new Evercade home console system. This package comes with: Evercade VS Console Evercade VS Controller Technos... View Article
+The post Evercade VS – What’s in the Box? appeared first on Evercade.
+ +
+
+
+
+ Evercade VS Founder Edition – How to get Your Name in the Evercade VS Credits
+Evercade 26 05 2021
+When we came up with the idea for the Evercade VS Founder Edition, we wanted to reward our fans and our most passionate adopters. To give them something that really allows them to become a part of the console and in some way to thank everyone for the passion, dedication and love shown from the... View Article
+The post Evercade VS Founder Edition – How to get Your Name in the Evercade VS Credits appeared first on Evercade.
+ +
+
+ 662
+Extra Ordinary 26 05 2021
+
+
+ Primeros pasos en Forge: Cómo desarrollar Apps en Atlassian Cloud (Parte 2: App para Confluence)
+En Mi Local Funciona 26 05 2021
+
+
+
+
+ App Store Arguments
+Stratechery by Ben Thompson 25 05 2021
+
+
+
+
+ What’s new for Microsoft Edge at Microsoft Build 2021
+Microsoft Edge Blog 25 05 2021
+Welcome back to Microsoft Build! Wherever this finds you, we hope that you’re safe and healthy.
+Since last Build, the Microsoft Edge platform continues to empower developers with the latest tools ready for today’s evolving web land
+The post What’s new for Microsoft Edge at Microsoft Build 2021 appeared first on Microsoft Edge Blog.
+ +
+
+ CSS Container Queries For Designers
+Ahmad Shadeed Blog 25 05 2021
+
+ 
+
+
+ Observer
+MonkeyUser 25 05 2021
+
+
+ +Principal Software Engineer +
++Brave Clojure Jobs + 24 05 2021
+Principal Software Engineer
Barracuda Networks | United States
remote
****Description****
++Come Join Our Passionate Team! At Barracuda, we make the world a safer place. We believe every business deserves access to cloud-enabled, enterprise-grade security solutions that are easy to buy, deploy, and use. We protect email, networks, data and applications with innovative solutions that grow and adapt with our customers' journey. More than 220,000 organizations worldwide trust Barracuda to protect them --- in ways they may not even know they are at risk --- so they can focus on taking their business to the next level.
We know a diverse workforce adds to our collective value and strength as an organization. Barracuda Networks is proud to be an Equal Opportunity Employer, committed to equal employment opportunity and equitable compensation regardless of race, gender, religion, sex, sexual orientation, national origin, or disability.
Envision yourself at Barracuda
We are looking for a Principal Software Engineer to join our distributed team. This is a great opportunity to work on large scale distributed systems underpinning our SaaS cloud applications for email security. These products process massive data coming at us in a steady stream with performance requirements in near real time. Our engineers know they make a difference because the solutions developed are protecting our customers against a growing number of threats. Each of our team members has varied talents that, together create an environment with a depth of knowledge. This allows for autonomy and innovation in developing solutions. The products we work on evolve with your added experience and likewise, you'll be immersed in a rewarding environment. We solve tough problems related to scalability and system architecture.
Tech Stack:
++
- Clojure, Elasticsearch, Kafka, Postgres, Kubernetes, Docker, AWS, Amazon Managed Services, Redis, Sumo Logic, etc.
+What you'll be working on:
++
- Solve important scaling problems around processing of huge volumes of data in near real-time and providing features atop petabytes of data under management.
+- Introduce advanced security features.
+- Drive design, implementation, and review of major areas of the codebase, adding new features and evolving our next generation architecture.
+- Contribute to a team that values code quality, innovative thinking, good communication, occasional pair programming, sound testing practices, and opportunities for mentoring.
+What you bring to the role:
++
- 8+ years of relevant experience delivering well-designed, scalable cloud software
+- Experience with functional programming (e.g. Clojure, java, etc.)
+- Experience with Lucene or Elasticsearch, or Streaming systems like Kafka
+- Demonstrated success in an Agile/Scrum development environment
+- Ability to communicate in a collaborative environment - in your code, in the documentation, and in chats and conversations with others
+- Bachelor's degree in a technology field or equivalent work experience
+- Ability to learn and adapt quickly in a high-energy environment
+- Knowledge of search, content management, and analytics is a plus
+- Exposure to Kubernetes is a plus
+What you'll get from us
A team where you can voice your opinion, make an impact, and where you and your experience are valued. Internal mobility -- there are opportunities for cross training and the ability to attain your next career step within Barracuda.
++
+- High-quality health benefits
+- Retirement Plan with employer match
+- Career-growth opportunities
+- Flexible Time Off and Paid Time Off benefits
+- Volunteer opportunities
+
-
+
- Job ID 22-081 +
+ 
+
+
+ Discovering the Lispworks IDE
+Lisp journey 24 05 2021
+LispWorks is a Common Lisp implementation +that comes with its own Integrated Development Environment (IDE) and +its share of unique features, such as the CAPI GUI toolkit. It is +proprietary and provides a free limited version.
+ +Here, we will mainly explore its IDE, asking ourselves what it can +offer to a seasoned lisper used to Emacs and Slime. The short answer +is: more graphical tools, such as an easy to use graphical stepper, a +tracer, a code coverage browser or again a class browser. Setting and +using breakpoints was easier than on Slime.
+ +LispWorks also provides more integrated tools (the Process browser +lists all processes running in the Lisp image and we can +stop, break or debug them) and presents many information in the form of +graphs (for example, a graph of function calls or a graph of all the +created windows).
+ +
+
+Note: you will find updated versions of this review on the Cookbook.
+
+
+
LispWorks features
+ +We can see a matrix of LispWorks features by edition and platform here: http://www.lispworks.com/products/features.html.
+ +We highlight:
+ +-
+
- 32-bit, 64-bit and ARM support on Windows, MacOS, Linux, Solaris, FreeBSD, +
- CAPI portable GUI toolkit: provides native look-and-feel on Windows, Cocoa, GTK+ and Motif.
+
+
-
+
- comes with a graphical “Interface Builder” (think QtCreator) (though not available on MacOS (nor on mobile)) +
+ - LispWorks for mobile runtime, for Android and iOS, +
- optimized application delivery: LispWorks can use a tree shaker to +remove unused lisp code from the delivered applicatiion, thus +shipping lighter binaries than existing open-source implementations. +
- ability to deliver a dynamic library, +
- a Java interface, allowing to call from Lisp to Java or the other way around, +
- an Objective-C and Cocoa interface, with drag and drop and multi-touch support, +
- a Foreign Language Interface, +
- TCP/UDP sockets with SSL & IPv6 support, +
- natived threads and symmetric multiprocessing, unicode support, and all other Common Lisp features, and all other LispWorks Enterprise features. +
And, of course, a built-in IDE.
+ +LispWorks is used in diverse areas of the industry. They maintain a list of success stories. As for software that we can use ourselves, we find ScoreCloud amazing (a music notation software: you play an instrument, sing or whistle and it writes the music) or OpenMusic (opensource composition environment).
+ +Free edition limitations
+ +The download instructions and the limitations are given on the download page.
+ +The limitations are the following:
+ +-
+
- There is a heap size limit which, if exceeded, causes the image to exit. A warning is provided when the limit is approached. +
What does it prevent us to do? As an illustration, we can not load this set of libraries together in the same image:
+ +(ql:quickload '("alexandria" "serapeum" "bordeaux-threads" "lparallel" "dexador" "hunchentoot" "quri" "ltk" "cl-ppcre" "mito"))
+-
+
There is a time limit of 5 hours for each session, after which LispWorks Personal exits, possibly without saving your work or performing cleanups such as removing temporary files. You are warned after 4 hours of use.
+
+It is impossible to build a binary. Indeed, the functions save-image, deliver (the function to create a stand-alone executable), and load-all-patches are not available.
+
+Initialization files are not loaded. If you are used to initializing Quicklisp from your
~/.sbclrcon Emacs, you’ll have to load an init file manually every time you start LispWorks ((load #p"~/.your-init-file)).
+
For the record, the snippet provided by Quicklisp to put in one’s startup file is the following:
+ +;; provided you installed quicklisp in ~/quicklisp/
+(let ((quicklisp-init (merge-pathnames "quicklisp/setup.lisp" (user-homedir-pathname))))
+ (when (probe-file quicklisp-init)
+ (load quicklisp-init)))
+You’ll have to paste it to the listener window (with the C-y key, y as “yank”).
-
+
- Layered products that are part of LispWorks Professional and Enterprise Editions (CLIM, KnowledgeWorks, Common SQL and LispWorks ORB) are not included. But we can try the CAPI toolkit. +
The installation process requires you to fill an HTML form to receive +a download link, then to run a first script that makes you accept the +terms and the licence, then to run a second script that installs the software.
+ +Licencing model
+ +LispWorks actually comes in four paid editions. It’s all explained by themselves here: http://www.lispworks.com/products/lispworks.html. In short, there is:
+ +-
+
- a Hobbyist edition with
save-imageandload-all-patches, to apply updates of minor versions, without the obvious limitations, for non-commercial and non-academic use,
+ - a HobbyistDV edition with the
deliverfunction to create executables (still for non-commercial and non-academic uses),
+ - a Professional edition, with the
deliverfunction, for commercial and academic uses,
+ - an Enterprise one, with their enterprise modules: the Common SQL interface, LispWorks ORB, KnowledgeWorks. +
At the time of writing, the licence of the hobbyist edition costs 750 USD, the pro version the double. They are bought for a LW version, per platform. They have no limit of time.
+ +
+
+NB: Please double check their upstream resources and don't hesitate to contact them.
+
+
+LispWorks IDE
+ +The LispWorks IDE is self-contained, but it is also possible to use LispWorks-the-implementation from Emacs and Slime (see below).
+ +The editor
+ +The editor offers what’s expected: a TAB-completion pop-up, syntax
+highlighting, Emacs-like keybindings (including the M-x extended
+command). The menus help the discovery.
We personally found the editing experience a bit “raw”. For example: +- indention after a new line is not automatic, one has to press TAB +again. +- the auto-completion is not fuzzy. +- there are no plugins similar to Paredit or Lispy, nor a Vim layer.
+ +We also had an issue, in that the go-to-source function bound to M-.
+did not work out for built-in Lisp symbols. This is probably a free
+edition limitation too.
The editor provides an interesting tab: Changed Definitions. It lists the functions and methods that were redefined since, at our choosing: the first edit of the session, the last save, the last compile.
+ +See also:
+ +-
+
- the Editor User Guide. +
Keybindings
+ +Most of the keybindings are similar to Emacs, but not all. Here are some differences:
+ +-
+
- to compile a function, use
C-S-c(control, shift and c), instead of C-c C-c.
+ - to compile the current buffer, use
C-S-b(instead of C-c C-k).
+
Similar ones include:
+ +-
+
C-gto cancel what you’re doing,
+C-x C-sto save the current buffer,
+M-wandC-yto copy and paste,
+M-b,M-f,C-a,C-e… to move around words, to go to the beginning or the end of the line,
+C-kto kill until the end of the line,C-wto kill a selected region,
+M-.to find the source of a symbol,
+C-x C-eto evaluate the current defun,
+- … +
Some useful functions don’t have a keybinding by default, for example:
+ + + +-
+
- clear the REPL with
M-x Clear Listener
+ Backward Kill Line
+
It is possible to use classical keybindings, à la KDE/Gnome. Go to the +Preferences menu, Environment and in the Emulation tab.
+ +There is no Vim layer.
+ +Searching keybindings by name
+ +It is possible to search for a keybinding associated to a function, or
+a function name from its keybinding, with the menu (Help -> Editing ->
+Key to Command / Command to Key) or with C-h followed by a key,
+as in Emacs. For example type C-h k then enter a keybinding to
+get the command name. See more with C-h ?.
Tweaking the IDE
+ +It is possible to change keybindings. The editor’s state is accessible
+from the editor package, and the editor is built with the CAPI
+framework, so we can use the capi interface too. Useful functions
+include:
`
+editor:bind-key
+editor:defcommand
+editor:current-point
+editor:with-point ;; save point location
+editor:move-point
+editor:*buffer-list*
+editor:*in-listener* ;; returns T when we are in the REPL
+…
+Here’s how you can bind keys:
+ +;; Indent new lines.
+;; By default, the point is not indented after a Return.
+(editor:bind-key "Indent New Line" #\Return :mode "Lisp")
+
+;; Insert pairs.
+(editor:bind-key "Insert Parentheses For Selection" #\( :mode "Lisp") ;;
+(editor:bind-key "Insert Double Quotes For Selection" #\" :mode "Lisp")
+Here’s how to define a new command. We make the ) key
+to go past the next closing parenthesis.
(editor:defcommand "Move Over ()" (p)
+ "Move past the next close parenthesis.
+Any indentation preceeding the parenthesis is deleted."
+ "Move past the next close parenthesis."
+ ;; thanks to Thomas Hermann
+ ;; https://github.com/ThomasHermann/LispWorks/blob/master/editor.lisp
+ (declare (ignore p))
+ (let ((point (editor:current-point)))
+ (editor:with-point ((m point))
+ (cond ((editor::forward-up-list m)
+ (editor:move-point point m)
+ (editor::point-before point)
+ (loop (editor:with-point ((back point))
+ (editor::back-to-indentation back)
+ (unless (editor:point= back point)
+ (return)))
+ (editor::delete-indentation point))
+ (editor::point-after point))
+ (t (editor:editor-error))))))
+
+(editor:bind-key "Move Over ()" #\) :mode "Lisp")
+And here’s how you can change indentation for special forms:
+ +(editor:setup-indent "if" 1 4 1)
+See also:
+ +-
+
- a list of LispWork keybindings: https://www.nicklevine.org/declarative/lectures/additional/key-binds.html +
The listener
+ +The listener is the REPL.
+ +Its interactive debugger is primarily textual but you can also +interact with it with graphical elements. For example, you can use the +Abort button of the menu bar, which brings you back to the top +level. You can invoke the graphical debugger to see the stacktraces +and interact with them. See the Debugger button at the very end of the +toolbar.
+ +
If you see the name of your function in the stacktraces (you will if +you wrote and compiled your code in a file, and not directly wrote it +in the REPL), you can double-click on its name to go back to the +editor and have it highlight the part of your code that triggered the +error.
+ +
+
+NB: this is equivalent of pressing
+
+M-v in Slime.
+The stepper. Breakpoints.
+ +The stepper is one +of the areas where LispWorks shines.
+ +When your are writing code in the editor window, you can set
+breakpoints with the big red “Breakpoint” button (or by calling M-x Stepper Breakpoint).
+This puts a red mark in your code.
The next time your code is executed, you’ll get a comprehensive Stepper pop-up window showing:
+ +-
+
- your source code, with an indicator showing what expression is being evaluated +
- a lower pane with two tabs:
+
+
-
+
- the backtrace, showing the intermediate variables, thus showing their evolution during the execution of the program +
- the listener, in the context of this function call, where you can evaluate expressions +
+ - and the menu bar with the stepper controls: you can step into the next expression, step on the next function call, continue execution until the position of the cursor, continue the execution until the next breakpoint, etc. +
That’s not all. The non-visual, REPL-oriented stepper is also nice. It shows the forms that are being evaluated and their results.
+ +In this example, we use :s to “step” though the current form and its subforms. We are using the usual listener, we can write any Lisp code after the prompt (the little -> here), and we have access to the local variables (X).
CL-USER 4 > (defun my-abs (x) (cond ((> x 0) x) ((< x 0) (- x)) (t 0)))
+CL-USER 5 > (step (my-abs -5))
+(MY-ABS -5) -> :s
+ -5 -> :s
+ -5
+ (COND ((> X 0) X) ((< X 0) (- X)) (T 0)) <=> (IF (> X 0) (PROGN X) (IF (< X 0) (- X) (PROGN 0)))
+ ;; Access to the local variables:
+ (IF (> X 0) (PROGN X) (IF (< X 0) (- X) (PROGN 0))) -> (format t "Is X equal to -5? ~a~&" (if (equal x -5) "yes" "no"))
+Is X equal to -5? yes
+ (IF (> X 0) (PROGN X) (IF (< X 0) (- X) (PROGN 0))) -> :s
+ (> X 0) -> :s
+ X -> :s
+ -5
+ 0 -> :s
+ 0
+ NIL
+ (IF (< X 0) (- X) (PROGN 0)) -> :s
+ (< X 0) -> :s
+ X -> :s
+ -5
+ 0 -> :s
+ 0
+ T
+ (- X) -> :s
+ X -> :s
+ -5
+ 5
+ 5
+ 5
+5
+Here are the available stepper commands (see :?):
:s Step this form and all of its subforms (optional +ve integer arg)
+:st Step this form without stepping its subforms
+:si Step this form without stepping its arguments if it is a function call
+:su Step up out of this form without stepping its subforms
+:sr Return a value to use for this form
+:sq Quit from the current stepper level
+:bug-form <subject> &key <filename>
+ Print out a bug report form, optionally to a file.
+:get <variable> <command identifier>
+ Get a previous command (found by its number or a symbol/subform within it) and put it in a variable.
+:help Produce this list.
+:his &optional <n1> <n2>
+ List the command history, optionally the last n1 or range n1 to n2.
+:redo &optional <command identifier>
+ Redo a previous command, found by its number or a symbol/subform within it.
+:use <new> <old> &optional <command identifier>
+ Do variant of a previous command, replacing old symbol/subform with new symbol/subform.
+The class browser
+ +The class browser allows us to examine a class’s slots, parent classes, available methods, and some more.
+ +Let’s create a simple class:
+ +(defclass person ()
+ ((name :accessor name
+ :initarg :name
+ :initform "")
+ (lisper :accessor lisperp
+ :initform t)))
+Now call the class browser:
+ +-
+
- use the “Class” button from the listener, +
- or use the menu Expression -> Class, +
- or put the cursor on the class and call
M-x Describe class.
+
It is composed of several panes:
+ +-
+
- the class hierarchy, showing the superclasses on the left and the subclasses on the right, with their description to the bottom, +
- the superclasses viewer, in the form of a simple schema, and the same for subclasses, +
- the slots pane (the default), +
- the available initargs, +
- the existing generic functions for that class +
- and the class precedence list. +
The Functions pane lists all methods applicable to that class, so we can discover public methods provided by the CLOS object system: initialize-instance, print-object, shared-initialize, etc. We can double-click on them to go to their source. We can choose not to include the inherited methods too (see the “include inherited” checkbox).
You’ll find buttons on the toolbar (for example, Inspect a generic +function) and more actions on the Methods menu, such as a way to see +the functions calls, a menu to undefine or trace a function.
+ +See more:
+ + + +The function call browser
+ +The function call browser allows us to see a graph of the callers and +the callees of a function. It provides several ways to filter the +displayed information and to further inspect the call stack.
+ +
+
+NB: The Slime functions to find such cross-references are
+
+slime-who-[calls, references, binds, sets, depends-on, specializes, macroexpands].
+After loading a couple packages, here’s a simple example showing who calls the string-trim function.
It shows functions from all packages, but there is a select box to restrict it further, for example to the “current and used” or only to the current packages.
+ +Double click on a function shown in the graph to go to its source. Again, as in many LispWorks views, the Function menu allows to further manipulate selected functions: trace, undefine, listen (paste the object to the Listener)…
+ +The Text tab shows the same information, but textually, the callers and callees side by side.
+ +We can see cross references for compiled code, and we must ensure the feature is on. When we compile code, LispWorks shows a compilation output likes this:
+ +;;; Safety = 3, Speed = 1, Space = 1, Float = 1, Interruptible = 1
+;;; Compilation speed = 1, Debug = 2, Fixnum safety = 3
+;;; Source level debugging is on
+;;; Source file recording is on
+;;; Cross referencing is on
+We see that cross referencing is on. Otherwise, activate it with (toggle-source-debugging t).
See more:
+ + + +The Process Browser
+ +The Process Browser shows us a list of all threads running. The input area allows to filter by name. It accepts regular expressions. Then we can stop, inspect, listen, break into these processes.
+ +
See more:
+ + + +Using LispWorks from Emacs and Slime
+ +To do that, start LispWorks normally, start a Swank server and connect to it from Emacs (Swank is the backend part of Slime).
+ +First, let’s load the dependencies:
+ +(ql:quickload "swank")
+;; or
+(load "~/.emacs.d/elpa/slime-20xx/swank-loader.lisp")
+Start a server:
+ +(swank:create-server :port 9876)
+;; Swank started at port: 9876.
+9876
+From Emacs, run M-x slime-connect, choose localhost and 9876 for the port.
You should be connected. Check with: (lisp-implementation-type). You are now able to use LispWorks’ features:
(setq button
+ (make-instance 'capi:push-button
+ :data "Button"))
+(capi:contain button)
+See also
+ +-
+
- LispWorks IDE User Guide (check out the sections we didn’t cover) +
- LispWorks on Wikipedia +
- the Awesome LispWorks list +
+ +
And voilà, our review ends here. I’m happy to have this tool under my toolbet, and I want to explore the CAPI toolkit more. But for now I don’t use LispWorks daily, so if you do, don’t hesitate to leave a comment with a tip or to highlight a feature you really like. Thanks!
+ +
+
+
+
+ A broader picture: A guide on imgproxy for businesses
+Martian Chronicles, Evil Martians’ team blog 24 05 2021
+
+
+
+
+ Preview Microsoft Math Solver in Microsoft Edge
+Microsoft Edge Blog 21 05 2021
+For many students, math can be a particularly challenging subject in school. Math is sequential, in that each lesson is part of the foundation for future learning. If students do not have a solid understanding of each concept as they go, it may impac
+The post Preview Microsoft Math Solver in Microsoft Edge appeared first on Microsoft Edge Blog.
+ +
+
+
+
+ Introducing the Evercade VS Founder Edition
+Evercade 21 05 2021
+UPDATE (27/05/21): The Evercade VS Limited Founder Edition is available NOW! Click the link below to pre-order yours UPDATE (27/05/21): Evercade VS Limited Founder Edition Additional Controllers will be available to Pre-Order from May 27, while stocks last. UPDATE (26/05/21): We have added a final exclusive Feature: Your Name in the Credits of the Evercade VS!... View Article
+The post Introducing the Evercade VS Founder Edition appeared first on Evercade.
+ +
+
+ vxdump: copias de seguridad en HP-UX
+ochobitshacenunbyte 19 05 2021
+Hoy echamos un vistazo rápido, a la herramienta de copias de seguridad, para sistemas de ficheros VxFS, en sistemas HP-UX, llamada vxdump. Me he tenido que pelear últimamente un poco con ella en este,...
+La entrada vxdump: copias de seguridad en HP-UX se publicó primero en ochobitshacenunbyte.
+ +
+
+ 661
+Extra Ordinary 19 05 2021
+
+
+
+
+ Cómo crear rápidamente newsletters en Mailchimp con diseños de plantillas profesionales
+Must Comunicación 19 05 2021
+
+
+
+
+ Arcade Games are Coming to Evercade!
+Evercade 18 05 2021
+Arcade games are coming to the Evercade with the announcement of four new cartridges! All four Arcade collections will feature arcade versions of the included games, from classic hits to some rediscovered greats. These new cartridges follow the now traditional Evercade formula of providing something everyone loves and something new to discover. In total, there... View Article
+The post Arcade Games are Coming to Evercade! appeared first on Evercade.
+ +
+
+
+
+ Distribution and Demand
+Stratechery by Ben Thompson 18 05 2021
+
+
+
+
+ Todo lo que los desarrolladores necesitan saber sobre el envío de emails transaccionales
+Must Comunicación 18 05 2021
+
+
+
+
+ The Right to Link
+The History of the Web 18 05 2021
+You can link to anything on the web. That's a strength. And yet the right to link has been dragged into court on a regular basis for decades. Why is that?
+The post The Right to Link appeared first on The History of the Web.
+ +
+ 
+
+
+ New Library
+MonkeyUser 18 05 2021
+
+
+ Google Summer of Code 2021 students are announced!
+Google Open Source Blog 17 05 2021
+
+
+ +Frontend Engineer +
++Brave Clojure Jobs + 17 05 2021
+Frontend Engineer
Multis | Europe
remote
About Multis
Multis provides financial services for companies holding euros, dollars, and cryptocurrencies. We are building the best crypto wallet designed for businesses who need to scale, move fast, make the most of their crypto and fiat currencies. We're helping these companies to shape a global and borderless economy through Decentralized Finance (DeFi)!
We're a team of happy and passionate crypto-dreamers: Thibaut (CEO) and Greg (CTO), with backing from world-class US and European investors like Y Combinator, Coinbase Ventures and eFounders. The company is incorporated in San Francisco but we're working from Europe for now.
What's so special about engineering at Multis?
Multis engineering is working at the cutting edge of FinTech and Blockchain with powerful technologies like ClojureScript, Re-frame and Firebase.
Our server-less architecture powered by functional programming is helping us to keep ourselves focused on our core domain and build a delightful experience.
Our engineering principles? Simplicity, quality and a magical UX!
Mission
We are looking for a frontend engineer to work hand-in-hand with the CTO and the engineering, product and design teams to build and maintain our next-gen business banking application in alignment with the different design prototypes.
As a core member, we also expect you to have major impact on shaping our culture and brand, and help us attract top talents!
Responsibilities
+-
+
- Conduct frontend developments --- from specs to tested production code --- along with the Product and Design teams +
- Contribute to Multis technical thought leadership through articles on our blog +
- Maintain product and handle company-wide support with the core team +
- Help build a world-class engineering team +
Requirements
+-
+
- Based in Europe +
- 3+ years of experience as frontend engineer with React +
- Acquainted with ClojureScript and re-frame (or strong willingness to learn --- our coding test is in ClojureScript) +
- Experience with complex single-page applications +
- Ability to lead projects and execute with pragmatism and velocity +
- Startup experience +
- Cultivate humility and curiosity about all things programming and tech +
- Know how to relax 🏝️ +
Nice to have
+-
+
- Experience in FinTech or Blockchain +
- Experience with a Design System (we use Ant.Design) +
- Previous remote experience +
- Hawaïan outfit and prior one-pot experience 🍲 +
Benefits
+-
+
- Challenging work experience building next-gen financial services with a frontier tech +
- Fast-learning environment, entrepreneurial and strong team spirit +
- Unique access to the Y Combinator and eFounders network +
- Competitive salary & equity +
- Remote-friendly company with HQ in Paris downtown (75010) +
- Team off-sites every 3 months (last one was in Berlin) +
- Possibility to get all or part of your salary in crypto 🤑 +
If you are interested, you are kindly asked to reach out to us by sending your CV on join@multis.co 😁
To learn more about Multis, our company and our mission check out our vital stats here.
+ 
+
+
+ ASERTIVIDAD Y ESTOICISMO
+Diario Estoico 16 05 2021
+
+
+
+
+ La web retorna a los 90
+República Web 14 05 2021
+Empezamos este episodio recordando la página web de la película Space Jam, que desde 1996 llevaba sin actualizarse. Un auténtica cápsula del tiempo en los inicios de la web, que muestra lo lejos que estamos de aquellos años. A pesar de todo, esos primeros años de la web, ayudaron a forjar unas herramientas de enorme utilidad, pero también una forma de producir y consumir los contenidos.
+ + + +Este episodio parte de un estupendo artículo de Max Böck titulado The return of the 90s web (junio 2020) donde se cuenta cómo la actual web está volviendo a lo que vivimos en esos últimos años del pasado siglo. Como explica el autor, es un buen momento para volver a visitar aquella web para encontrar, si en efecto vuelven tendencias con un aire renovado.
+ + + +Entre las tendencias que destaca Max y que se reproducen en el podcast nos encontramos:
+ + + +- Renderizado en el servidor.
- Herramientas no-code.
- Sitios web personales.
- Feeds curados, RSS y descubrimiento de contenido.
- Comunidades y monetización de la web.
Hace 25 años la web era un territorio sin mapas y algo anárquico. Hoy es un lugar que sigue creando oportunidades y propiciando conexiones. Como se comenta en el episodio del podcast, en estos años hemos aprendido mucho y es bueno comprobar que las cosas con valor vuelven (si es que se han ido alguna vez).
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Modernizing Oracle operations with Kubernetes and El Carro
+Google Open Source Blog 13 05 2021
+
+
+ Primeros pasos en Forge: Cómo desarrollar Apps en Atlassian Cloud (Parte 1: App para Jira)
+En Mi Local Funciona 12 05 2021
+
+
+ 660
+Extra Ordinary 12 05 2021
+
+
+
+
+ Cloudflare on the Edge
+Stratechery by Ben Thompson 11 05 2021
+
+
+ A Look at Tailwind CSS
+Ahmad Shadeed Blog 11 05 2021
+
+
+
+
+ Eleventy es mucho más que un generador de sitios estáticos
+República Web 07 05 2021
+Los sitios web estáticos vuelven a estar de moda y hay un generador de sitios estáticos en JavaScript que enamora a la comunidad de developers. Con una apuesta clara por la simplicidad, Eleventy es mucho más que un generador de sitios estáticos. Creado y gestionado por Zach Leatherman, Eleventy es una potente herramienta para producir sitios web optimizados y preparados para el rendimiento.
+ + + +En este episodio se realiza un análisis de Eleventy explicando qué lo hace tan especial para la comunidad. En poco tiempo Eleventy ha conseguido reunir una vibrante comunidad de desarrolladores, que comparten ingeniosas soluciones basadas en apalancar la formidable librería de JavaScript. Por si fuera poco Eleventy, gracias a servicios como Netlify o Vercel, está entre las herramientas más populares para producir sitios web basados en la arquitectura Jamstack. Entre las ventajas de Eleventy:
+ + + +- Soporta 11 lenguajes de plantilla.
- Cascada de datos locales, globales y externos.
- Cero configuración (no asume ninguna convención).
- Extensión a través de plugins, shortcodes y transformadores.
- Orientado al rendimiento y a la velocidad.
- Comunidad.
Aunque Eleventy pueda ser usado para crear un sitio estático convencional, la combinación de un servicio como Netlify o Vercel, te ofrece una secuencia perfecta para desarrollar sitios web modernos y orientados al rendimiento y la productividad.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ Mejores plugins SEO para WordPress
+Must Comunicación 06 05 2021
+
+
+
+
+ Indie Heroes and Worms Delayed to July 30 2021
+Evercade 05 05 2021
+We have an update for you on the release date of Cartridges 17 & 18, Indie Heroes Collection 1 and Worms Collection 1, and sadly it is not good news. The release date of these cartridges has unfortunately had to be delayed to July 30th, 2021 due to a supply issue beyond our control. This... View Article
+The post Indie Heroes and Worms Delayed to July 30 2021 appeared first on Evercade.
+ +
+
+
+
+ The Bitmap Brothers Collection 1 Announced
+Evercade 05 05 2021
+We are delighted to announce another brand new collection that highlights some of the best games in the history of British video game development with The Bitmap Brothers Collection 1 for Evercade devices. This new collection, in partnership with owners Rebellion, features 5 of the best games from the British development team that was dubbed... View Article
+The post The Bitmap Brothers Collection 1 Announced appeared first on Evercade.
+ +
+
+
+
+ Mejores temas de WordPress para contenido viral
+Must Comunicación 05 05 2021
+
+
+
+
+ Market-Making on the Internet
+Stratechery by Ben Thompson 05 05 2021
+
+
+ +Clojure developer +
++Brave Clojure Jobs + 05 05 2021
+Clojure developer
Ardoq | flexible remote in/around Oslo. Visa sponsorship is possible
Ardoq is a fast-growing technology company in Norway with offices in London, New York, and Copenhagen. Our Graph platform enables our customers to map dependencies across strategic objectives, projects, applications, processes, and people, allowing them to assess the impact of change and make better and faster decisions.
Our company is backed by a solid commitment from investors and a majority of our employees are also shareholders. We're growing rapidly, and are looking for candidates to help scale our engineering team.
Ardoq's engineering team is a highly skilled group of people who like solving challenging problems, value feedback, continuous delivery, and automation of repetitive tasks. We maintain a high iteration speed through a focus on code quality and incremental change, not artificial deadlines. We believe working closely together and supporting each other is important if we are to achieve a common goal.
Who we're looking for
We're looking for caring, driven, and quality-focused engineers who can collaborate across the organization. You should have a learning and sharing mindset. That is, wanting to learn new things and being open and sharing your knowledge. As the company develops we implement our lessons learned and adapt to change. You should be proactive and take ownership.
We believe in finding people with the right qualities and skills rather than finding a person with the right degree. A BS/MS degree in Computer Science, Engineering, or related subject is always good but it's not a prerequisite.
You should have a good knowledge of web technologies and an interest in working with a functional language, as Clojure is our primary back-end language.
We think it's a plus if you consider yourself a full stack developer and don't mind getting your hands dirty. Since JavaScript/TypeScript and Clojure are quite different, we don't expect you to be an expert in both, but it is good to have an understanding of the other side.
Responsibilities
You'll be an integral part of the engineering team. This means both working with greenfield feature development, finding bugs, and focusing on continuous quality improvement. There's also the possibility of helping on cloud infrastructure, automation, and developer tooling depending on your personal interests.
Our best work is done in an environment of mutual trust and support. We share knowledge and value diversity. We are proactive and volunteer our best effort every day. If we see a problem, we fix a problem.
What we can offer you
Ardoq's values are Bold, Caring and Driven. Living by these values is part of what makes Ardoq a great place to work. We make bold decisions that push the product, ourselves and our customers forward. We voice our opinions, have difficult conversations, disagree, and learn. We take care of both our colleagues and our customers and empathize with the challenges they face every day.
We also offer many benefits including investment opportunities for employees and generous parental leave schemes.
Although we have offices in Oslo, London, New York, and Copenhagen, we embrace remote work and flexible schedules.
If you identify with this, we can offer you a really great place to work.
Work language
English & Clojure. Although 44% of us are based at the Oslo headquarters, we are an international team representing many countries and languages.
+
+ 659
+Extra Ordinary 05 05 2021
+
+
+ Phaser 3: Mi primer juego HTML5/JS (Parte 2)
+En Mi Local Funciona 04 05 2021
+
+
+
+
+ Checking “Under the Hood” of Code
+The History of the Web 04 05 2021
+If you're a developer today, you likely take advantage of built in tools for web debugging every day. They came from the smallest places, and it took years to get them where they are today.
+The post Checking “Under the Hood” of Code appeared first on The History of the Web.
+ +
+
+ The State of CSS Cross-Browser Development
+Ahmad Shadeed Blog 04 05 2021
+
+
+
+
+ LAS VIRTUDES ESTOICAS.
+Diario Estoico 02 05 2021
+
+
+
+
+ El apocalipsis de las cookies de terceros
+República Web 02 05 2021
+Google anunció que a partir de mayo 2022 su navegador Chrome dejará de permitir la carga de cookies de terceros. Esto se añade a una larga lista de acciones que rematan las cookies de terceros como medio para la identificación y el seguimiento de usuarios para la industria de los anuncios publicitarios (AdTech).
+ + + +En este episodio se habla sobre las implicaciones que traen el ocaso de las cookies de terceros y la tendencia hacia alternativas que sirvan para reemplazarlas. Teniendo en cuenta que las cookies de terceros han permitido la financiación de muchos servicios en internet, el hecho de que el navegador más usado en el mundo las deje de permitir, genera mucha incertidumbre entre la industria publicitaria y los creadores de contenido.
+ + + +En la segunda parte del episodio ofrezco una serie de ideas para conciliar un internet abierta y que al mismo tiempo sea económicamente viable. La muerte de las cookies de terceros es la crónica de una muerte anunciada, pero que supone cambios en la forma en la que usamos gran parte de los servicios más populares en internet.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ Intellivision Collection 1 Games Announced
+Evercade 01 05 2021
+That’s right, it’s been a few months but we’re finally ready to let you know exactly what is on the upcoming Intellivision Collection 1 Cartridge from Evercade! The Games list is: Astrosmash (Shoot ’em Up) Buzz Bombers (Shoot ’em Up) Frog Bog (Eat ’em Up) Night Stalker (Action) Pinball Princess Quest (Platformer) Shark Shark (Puzzle)... View Article
+The post Intellivision Collection 1 Games Announced appeared first on Evercade.
+ +
+
+ Free Software Wireless-N Mini Router v3 from ThinkPenguin, Inc. now FSF-certified to Respect Your Freedom
+FSF News 30 04 2021
+
+
+ El Desconocido CSS
+En Mi Local Funciona 30 04 2021
+
+
+ FSF board frequently asked questions (FAQ)
+FSF News 28 04 2021
+
+
+ +Clojurescript Engineer (Remote) +
++Brave Clojure Jobs + 28 04 2021
+Clojurescript Engineer (Remote)
Composer | US & Canada
remote
Build, test, and deploy automated trading strategies without any code!
$130000 - $200000
Build the platform that will disrupt the portfolio management industry!
Composer is a no-code platform for automated investment management. Composer allows you to build, test, deploy, and manage automated investing strategies - all without writing a line of code.
As an early frontend engineer at Composer you will:
+-
+
- Be responsible for everything our clients interact with on our platform - empathy for user experience is a must +
- Work closely with the executive team to guide our decisions regarding frontend architecture +
- Work closely with our designer to bring the product to life +
Projects you will work on:
+-
+
- Bringing to life our simple yet powerful portfolio manager and strategy creation tool +
- Unifying scattered brokerage accounts to create a holistic portfolio view +
We're looking for someone who:
+-
+
- Loves Clojurescript (particularly Reagent & Reframe!) +
- Has experience working with designers and translating complex designs into clean, simple code +
- Has experience implementing design systems, or has a systems approach to building +
- Will be a technical thought leader within the company +
What's it like to work at Composer?
+-
+
- We believe diverse perspectives are necessary if we aim to disrupt finance. To that end, we are an equal opportunity employer and welcome a wide array of backgrounds, experiences, and abilities. +
- We believe the simplest solution is most likely the best one +
- We encourage self-improvement and learning new skills +
- We are venture-backed by top investors +
- We are 100% remote :) +
- Our Values +
+
+ Instalación de Icinga 2 e Icinga Web 2 en Centos 8
+ochobitshacenunbyte 28 04 2021
+Volvemos a la carga con el popular producto de monitoreo de infraestructuras llamado Icinga, en este caso vemos su instalación sobre un servidor con Centos 8. Ya he hablado en varias ocasiones sobre esta...
+La entrada Instalación de Icinga 2 e Icinga Web 2 en Centos 8 se publicó primero en ochobitshacenunbyte.
+ +
+
+
+
+ Spotify’s Surprise
+Stratechery by Ben Thompson 28 04 2021
+
+
+ 658
+Extra Ordinary 28 04 2021
+
+ 
+
+
+ Confidence
+MonkeyUser 28 04 2021
+
+
+ Cinco herramientas de backup de escritorio en Linux
+ochobitshacenunbyte 27 04 2021
+Os hablo sobre las cinco mejores herramientas de backup de escritorio, para sistemas GNU/Linux. Estas herramientas las he probado en una distribución Ubuntu 20.04, pero entiendo que deben estar disponibles para la mayoría de...
+La entrada Cinco herramientas de backup de escritorio en Linux se publicó primero en ochobitshacenunbyte.
+ +
+
+
+
+ April 2021 Weblog: Holding on to our History
+The History of the Web 27 04 2021
+When websites disappear, how do we make sure that our history is preserved?
+The post April 2021 Weblog: Holding on to our History appeared first on The History of the Web.
+ +
+ 
+
+
+ SonarQube: Ejecución de análisis e inspección continua (Parte 3)
+En Mi Local Funciona 27 04 2021
+En el anterior post (Cómo montar un SonarQube en cloud que nos sirva de Spike (Parte 1)) se quiso dar una respuesta rápida a la instalación de SonarQube.
+ +
En este post, se quiere continuar el ciclo de vida, y explicar de manera abreviada los siguientes temas:
+ +-
+
- Cómo se lanza una
+
+ Practical Use Cases For CSS Variables
+Ahmad Shadeed Blog 27 04 2021
+
+
+ Netplan: Configurar la red en Ubuntu 20.04
+ochobitshacenunbyte 26 04 2021
+Seguramente te habrás dado cuenta, que en las últimas versiones de Ubuntu la configuración de la red ha cambiado. Vamos a ver como configurar la red en Ubuntu 20.04 con la herramienta Netplan. La...
+La entrada Netplan: Configurar la red en Ubuntu 20.04 se publicó primero en ochobitshacenunbyte.
+ +
+
+ Practical SQL for Data Analysis
+Haki Benita 25 04 2021
+Pandas is by far the most popular tool for data analysis. It's packed with useful features, it's battle tested and widely accepted. However, pandas comes at a cost which is often overlooked. SQL databases has been around since the 1970s. They contain many features that most developers never heard of, and I want to bring some of them to light.
+
+
+
+
+ ¿QUÉ ES EL ESTOICISMO? DEFINICIÓN DE ESTOICISMO, Y CLAVES PARA ENTENDER LA FILOSOFÍA ESTOICA.
+Diario Estoico 25 04 2021
+
+
+
+
+ Testing de End-to-End (E2E) – Informe Testing (III)
+República Web 24 04 2021
+Tercer episodio de la serie especial sobre testing donde tratamos el testing de extremo a extremo (End-2-End). Se trata del testing que involucra toda la experiencia de uso de una aplicación. El E2E es la técnica testing de más alto nivel dentro del desarrollo web. Ya no tocamos el código sino sus resultados en el navegador, ya que se pretende emular a través de pruebas determinados comportamientos que debe cumplir nuestra aplicación. Pensemos en este testing como un robot que usa nuestra aplicación, simulando acciones y peticiones realizadas desde un «navegador descabezado».
+ + + +En este episodio Javier Archeni y Andros Fenollosa hablan sobre el testing E2E, dónde encaja y en especial los frameworks que existen para realizar este tipo de tests. En el episodio:
+ + + +-
+
- ¿Qué es E2E? +
- ¿Por qué existe? +
- ¿Cuándo debería utilizarse? +
- ¿Cuáles son sus limitaciones? +
- Tipo de usos en escritorio y móviles +
- Frameworks de testing E2E +
Un episodio de introducción general a este tipo de testing que seguro dará para profundizar más. Os animamos a probar esta metodología como una forma de mejorar vuestro trabajo y al mismo tiempo ofrecer un mejor servicio en vuestros desarrollos.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+ 
+
+
+ Perfect Fit
+MonkeyUser 23 04 2021
+
+
+ pfSense cómo cortafuegos en red interna de VirtualBox
+ochobitshacenunbyte 22 04 2021
+Os explico en esta entrada cómo configurar un cortafuegos con el producto pfSense, en una red interna de VirtualBox. La idea es instalar y configurar el popular producto pfSense, usando la ISO que nos...
+La entrada pfSense cómo cortafuegos en red interna de VirtualBox se publicó primero en ochobitshacenunbyte.
+ +
+
+ 2021 Board Election Results
+News on Clojurists Together 22 04 2021
+
+
+ Bases de datos seguras en Android
+En Mi Local Funciona 21 04 2021
+
+
+
+
+ Trying (and Failing) to be Cool
+The History of the Web 20 04 2021
+The web's turn into commercial may have happened quickly—it was largely complete by the end of the 1990's—but that doesn't mean it didn't take a turn into the weird here and there. Case and point: Zima.
+The post Trying (and Failing) to be Cool appeared first on The History of the Web.
+ +
+
+
+
+ Plugins prémium de gráficos para WooCommerce y WordPress (y 5 gratuitos)
+Must Comunicación 18 04 2021
+
+
+
+
+ Pipeline de servidor – Informe Testing (II)
+República Web 17 04 2021
+Segundo episodio de esta serie especial sobre testing. En esta ocasión Andros Fenollosa conversa con Antony Goetzschel sobre el testing en el lado de servidor. Entre las cuestiones que discuten en el episodio:
+ + + +-
+
- ¿Qué es un pipeline? +
- ¿Dónde se ensambla el código? +
- ¿Tienes sentido hacerlo en el CI/CD? +
- ¿Cómo se puede empezar con un CI/CD? +
- ¿Cuál es la utilidad de hacer testing en el despliegue? +
- ¿Qué son las pruebas de estrés? +
- ¿Cómo se hacen? +
- El monitoreo que se realiza a un servicio… ¿dónde podríamos caracterizarlo? +
- ¿Qué técnicas utilizas en tu día a día? ¿Por qué? +
Este episodio ofrece una perspectiva muy amplia sobre lo que implica probar nuestro código en la parte del servidor, con recomendaciones de Andros y Antony.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Season of Docs announces participating organizations for 2021
+Google Open Source Blog 16 04 2021
+
+
+ SSMTP: Envío fácil de correo desde la consola de comandos en Linux
+ochobitshacenunbyte 16 04 2021
+Existen diferentes tipos de programas en GNU/Linux encargados de enviar correo. En el caso de hoy os hablaré de SSMTP, un programa que conozco desde hace no mucho, pero que me consta que en...
+La entrada SSMTP: Envío fácil de correo desde la consola de comandos en Linux se publicó primero en ochobitshacenunbyte.
+ +
+
+
+
+ Mega Cat Studios Collection 2 is coming to Evercade
+Evercade 15 04 2021
+We’re delighted to announce the Mega Cat Studios Collection 2 cartridge which will feature 8 more classic Mega Cat Studios games to the Evercade! The new 8 game collection, due for release on September 29th 2021, will bring more games from the independent publisher. following the great reception of Mega Cat Studios Collection 1 which... View Article
+The post Mega Cat Studios Collection 2 is coming to Evercade appeared first on Evercade.
+ +
+
+
+
+ Los mejores plugins para crear tablas de WordPress
+Must Comunicación 15 04 2021
+
+
+ Las tripas de SonarQube: Métricas y cómo calcula el Rating (Parte 2)
+En Mi Local Funciona 15 04 2021
+
+
+ Meeting
+MonkeyUser 15 04 2021
+
+
+
+
+ Mejores temas de WooCommerce para vender productos digitales
+Must Comunicación 14 04 2021
+
+
+
+
+ Mejores plugins de localización de tiendas para WordPress
+Must Comunicación 14 04 2021
+
+
+
+
+ Mejores temas WooCommerce de muebles para WordPress
+Must Comunicación 14 04 2021
+
+
+ Why My Blog is Closed-Source
+Josh Comeau's blog 14 04 2021
+
+
+
+
+ From zero to hero: Building and scaling Groupon Russia
+Martian Chronicles, Evil Martians’ team blog 14 04 2021
+
+ 
+
+
+ Implementar un aviso de cookies para cumplir con la normativa RGPD en el 2021
+Javier Archeni 13 04 2021
+
+
+ YUM, solventar fatal error, run database recovery
+ochobitshacenunbyte 13 04 2021
+Ya sabéis que utilizo la web para mis apuntes personales, así que otra va, en este caso para solventar un problema con YUM, que como sabéis se encarga, en versiones antiguas de RHEL o...
+La entrada YUM, solventar fatal error, run database recovery se publicó primero en ochobitshacenunbyte.
+ +
+
+ Actuating Google Production: How Google’s Site Reliability Engineering Team Uses Go
+Google Open Source Blog 13 04 2021
+
+
+ Phaser 3: Mi primer juego HTML5/JS (Parte 1)
+En Mi Local Funciona 13 04 2021
+Introducción
+ +¿Qué programador no ha soñado con participar en la creación de un videojuego? No sé vosotros, pero a mí siempre me ha gustado la idea de desarrollar un pequeño juego, ya desde los tiempos del Commodore 64 o del Sinclair Spectrum, que me ponía a copiar el código "Basic"
+
+
+ Say Hello To CSS Container Queries
+Ahmad Shadeed Blog 13 04 2021
+
+ 
+
+
+ Introduction
+MonkeyUser 13 04 2021
+
+
+ Logica: organizing your data queries, making them universally reusable and fun
+Google Open Source Blog 12 04 2021
+
+
+ Statement of FSF board on election of Richard Stallman
+FSF News 12 04 2021
+
+
+ RMS addresses the free software community
+FSF News 12 04 2021
+
+
+ Would Alfred Hitchcock use Emacs?
+Manuel Uberti 12 04 2021
+First you have to excuse the awful title, but a cinephile cannot resist the +temptation of an easy reference when the Emacs package he is going to write +about is called Vertico.
+ +Daniel Mendler has become such a prolific contributor to our Emacs world. His
+work with Omar Antolín Camarena and Clemens Radermacher (to name a few!) has
+been showing me how much can be done with little improvements on Emacs default
+completion system. Actually, “little” is a bit unfair to them because they have
+been putting a lot of effort in their packages and contributions. What “little”
+stands for instead is the amount of code I had to add to my init.el to get a
+superb completion UI. I combine Vertico with Orderless and I didn’t have to do
+much beside this after the installation via package.el:
(require 'orderless)
+ (setq completion-styles '(orderless))
+
+ (require 'vertico)
+ (vertico-mode +1)
+Well, to be fair I did something more, like binding vertico-exit-input to C-j
+and setting orderless-matching-styles to orderless-regexp, plus I am using
+Daniel’s consult to extend Vertico capabilities, but I guess you see where I am
+going by now. The combination of small packages makes for a modular system that
+I can interact with more easily. For instance, Daniel can go berserk and forget
+about the lovely 500 lines of code limit he set himself to with Vertico. Why
+should I trust this criminal mind, then? I can switch to Selectrum and keep
+using Consult and Orderless with it1.
The beauty of Vertico is that it is not about reinventing Emacs completion once +again. By sticking to Emacs built-in commands and completion facilities, Vertico +succeeds in staying close to the source without losing the chance to improve on +it. On the one hand, moving to Vertico means it is up to the user to configure +extra niceties. That is what packages like Consult, Orderless, Embark, and +Marginalia aim for, but again, the user is in charge of the right setup for +their needs, while a solution such as Helm offers a lot of functionalities out +of the box. On the other hand, tools such as Helm, Ivy, and Selectrum are more +complex than Vertico and may bring in code you do not necessarily need, which is +something even Emacs itself doesn’t shy away from2.
+ +I find it amazing that a seemingly simple and yet so central feature in my +everyday Emacs such as the completion system has pushed people to create all +these amazing packages. It seems to me that Helm has helped pave the way for a +more powerful experience when it comes to completion and that by studying Emacs +internals carefully one can achieve similar benefits with a different approach. +As humble end-users of all this we really are a lucky bunch.
+ +Notes
+ + + +
+
+ Would Alfred Hitchcock use Emacs?
+Manuel Uberti 12 04 2021
+First you have to excuse the awful title, but a cinephile cannot resist the +temptation of an easy reference when the Emacs package he is going to write +about is called Vertico.
+ +Daniel Mendler has become such a prolific contributor to our Emacs world. His
+work with Omar Antolín Camarena and Clemens Radermacher (to name a few!) has
+been showing me how much can be done with little improvements on Emacs default
+completion system. Actually, “little” is a bit unfair to them because they have
+been putting a lot of effort in their packages and contributions. What “little”
+stands for instead is the amount of code I had to add to my init.el to get a
+superb completion UI. I combine Vertico with Orderless and I didn’t have to do
+much beside this after the installation via package.el:
(require 'orderless)
+ (setq completion-styles '(orderless))
+
+ (require 'vertico)
+ (vertico-mode +1)
+Well, to be fair I did something more, like binding vertico-exit-input to C-j
+and setting orderless-matching-styles to orderless-regexp, plus I am using
+Daniel’s consult to extend Vertico capabilities, but I guess you see where I am
+going by now. The combination of small packages makes for a modular system that
+I can interact with more easily. For instance, Daniel can go berserk and forget
+about the lovely 500 lines of code limit he set himself to with Vertico. Why
+should I trust this criminal mind, then? I can switch to Selectrum and keep
+using Consult and Orderless with it1.
The beauty of Vertico is that it is not about reinventing Emacs completion once +again. By sticking to Emacs built-in commands and completion facilities, Vertico +succeeds in staying close to the source without losing the chance to improve on +it. On the one hand, moving to Vertico means it is up to the user to configure +extra niceties. That is what packages like Consult, Orderless, Embark, and +Marginalia aim for, but again, the user is in charge of the right setup for +their needs, while a solution such as Helm offers a lot of functionalities out +of the box. On the other hand, tools such as Helm, Ivy, and Selectrum are more +complex than Vertico and may bring in code you do not necessarily need, which is +something even Emacs itself doesn’t shy away from2.
+ +I find it amazing that a seemingly simple and yet so central feature in my +everyday Emacs such as the completion system has pushed people to create all +these amazing packages. It seems to me that Helm has helped pave the way for a +more powerful experience when it comes to completion and that by studying Emacs +internals carefully one can achieve similar benefits with a different approach. +As humble end-users of all this we really are a lucky bunch.
+ +Notes
+ + + +
+
+
+
+ Hotwire: Reactive Rails with no JavaScript?
+Martian Chronicles, Evil Martians’ team blog 12 04 2021
+
+
+ Подкаст DevZen, эпизод 331
+tonsky.me 10 04 2021
+
+
+ Announcing the First Group of Google Open Source Peer Bonus winners in 2021!
+Google Open Source Blog 08 04 2021
+
+
+ Announcing Board Nominations
+News on Clojurists Together 08 04 2021
+
+
+ Back to the roots
+Manuel Uberti 08 04 2021
+Last time I left straight for the built-in package.el, a choice I have not had
+the pleasure to regret so far. Now I am going to reason about a more ambitious
+change in my Emacs configuration: I am not using use-package any more.
Before answering your concerned why!? let me just say that if you are happy with
+use-package you should stay with it. By wrapping all the settings to a built-in
+feature or an external package with use-package you can easily notice what you
+are doing wrong when tweaking something, while having control over the
+installation and the loading of your favourite library as well. Despite some
+unhappiness around the web1, use-package is just a great tool that any serious
+Emacs hacker should consider when digging deep into their .emacs.d.
As for my choice to move away from it, it all started as an experiment. I wanted
+to see if I could have the same amount of control and readability over my
+init.el without an extra package. You see, most of the recent changes to my
+setup involved trying to rely on Emacs own facilities to answer my needs, and
+I am glad to say vanilla Emacs has been really a surprise in this regard. My
+liaisons with project.el and Flymake are nice examples of this.
Removing use-package has meant rethinking the way I install packages, especially
+if I want my setup to be ready to go any time I upgrade to a newer version of
+Ubuntu. My solution was adding the packages I use to package-selected-packages
+and have a check on startup to make sure they are installed. This works very
+well combined with package-autoremove: if a package is not listed under
+package-selected-packages, Emacs takes care of the mess.
All the use-package blocks have been replaced with a combination of
+with-eval-after-load, define-key, and add-hook, which was not as complicated as
+it might sound, and more often than not was similar to what I had in my days
+before the use-package takeover. True, I lost the nice readability of
+use-package with this massive edit. For example, its keywords have the benefit
+of grouping settings together and clearly indicate when a new group starts, but
+on the other hand now there is less macro-magic masking package-related
+operations involved. As a result I have a more detailed insight of what is
+really going on with my Emacs Lisp. For instance, I have gained a better
+knowledge of what run-with-idle-timer actually does.
Again, it is a matter of personal preferences. By now the beauty of use-package
+is well-known in the Emacs world and all the praises are well-deserved. Let me
+stress it again: use-package makes your configuration simpler to manage and
+easier to read. Those were the main reasons I switched to it years ago, anyway.
However, if you know what you are doing you can achieve a clean and pleasant
+init.el with what Emacs already offers. Does it take more effort? Yes, it
+probably does. Is it really worth it? It’s up to you, mate. Am I just showing
+off? No, come on, don’t be rude.
Notes
+ + + +
+
+ Back to the roots
+Manuel Uberti 08 04 2021
+Last time I left straight for the built-in package.el, a choice I have not had
+the pleasure to regret so far. Now I am going to reason about a more ambitious
+change in my Emacs configuration: I am not using use-package any more.
Before answering your concerned why!? let me just say that if you are happy with
+use-package you should stay with it. By wrapping all the settings to a built-in
+feature or an external package with use-package you can easily notice what you
+are doing wrong when tweaking something, while having control over the
+installation and the loading of your favourite library as well. Despite some
+unhappiness around the web1, use-package is just a great tool that any serious
+Emacs hacker should consider when digging deep into their .emacs.d.
As for my choice to move away from it, it all started as an experiment. I wanted
+to see if I could have the same amount of control and readability over my
+init.el without an extra package. You see, most of the recent changes to my
+setup involved trying to rely on Emacs own facilities to answer my needs, and
+I am glad to say vanilla Emacs has been really a surprise in this regard. My
+liaisons with project.el and Flymake are nice examples of this.
Removing use-package has meant rethinking the way I install packages, especially
+if I want my setup to be ready to go any time I upgrade to a newer version of
+Ubuntu. My solution was adding the packages I use to package-selected-packages
+and have a check on startup to make sure they are installed. This works very
+well combined with package-autoremove: if a package is not listed under
+package-selected-packages, Emacs takes care of the mess.
All the use-package blocks have been replaced with a combination of
+with-eval-after-load, define-key, and add-hook, which was not as complicated as
+it might sound, and more often than not was similar to what I had in my days
+before the use-package takeover. True, I lost the nice readability of
+use-package with this massive edit. For example, its keywords have the benefit
+of grouping settings together and clearly indicate when a new group starts, but
+on the other hand now there is less macro-magic masking package-related
+operations involved. As a result I have a more detailed insight of what is
+really going on with my Emacs Lisp. For instance, I have gained a better
+knowledge of what run-with-idle-timer actually does.
Again, it is a matter of personal preferences. By now the beauty of use-package
+is well-known in the Emacs world and all the praises are well-deserved. Let me
+stress it again: use-package makes your configuration simpler to manage and
+easier to read. Those were the main reasons I switched to it years ago, anyway.
However, if you know what you are doing you can achieve a clean and pleasant
+init.el with what Emacs already offers. Does it take more effort? Yes, it
+probably does. Is it really worth it? It’s up to you, mate. Am I just showing
+off? No, come on, don’t be rude.
Notes
+ + + +
+
+ Shy Coder
+MonkeyUser 08 04 2021
+
+
+ Analyzing genomic data in families with deep learning
+Google Open Source Blog 07 04 2021
+
+
+ Inspect Element As A Way To Increase Your Curiosity
+Ahmad Shadeed Blog 07 04 2021
+
+
+ Мы обречены — Open Source
+tonsky.me 07 04 2021
+
+
+
+
+ ¿Qué es el testing? – Informe Testing I
+República Web 06 04 2021
+Primer episodio de una serie especial que vamos a dedicar al mundo del testing. Para esta primera parte Andros Fenollosa repasa con David las metodologías de testing, discutiendo además las ventajas y las desventajas de seguir realizar pruebas en nuestro código. Entre las cuestiones habladas:
+ + + +-
+
+
- Filosofías
+
-
+
- Desarrollo guiado por pruebas (TDD). +
- Desarrollo guiado por el comportamiento (BDD). +
- Desarrollo guidado a datos (DDD). + +
- Frameworks de testing + + +
- Pruebas dependiendo de la visibilidad
+
+
-
+
- Pruebas de caja blanca. +
- Pruebas de caja gris. +
- Pruebas de caja negra + +
+
+
+ - Pruebas dependiendo de la ejecución de las aplicaciones
+
+
-
+
- Pruebas estáticas +
- Pruebas dinámicas +
+
+
+ - Pruebas Funcionales
+
+
-
+
- Pruebas de unidad +
- Pruebas de integración +
- Pruebas de aceptación +
- Pruebas de extremo a extremo (E2E) +
+
+ - Pruebas no Funcionales + +
- Pruebas de rendimiento + +
- Pruebas de seguridad +
- Pruebas aleatorias (Fuzzing). + +
- Pruebas según el número de pruebas a realizar
+
-
+
- Pruebas de humo +
- Pruebas de sanidad +
- Pruebas de regresión/sistema +
+
+
Se trata de un episodio de introducción al testing, hablando también sobre las consideraciones habituales al tratar esta metodología en los equipos y empresas. También hablan de algunas experiencias relacionadas con el testing.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Lyra - enabling voice calls for the next billion users
+Google Open Source Blog 06 04 2021
+
+
+ Mosh, un ssh más eficiente en Linux
+ochobitshacenunbyte 06 04 2021
+La entrada de hoy va dedicada a mosh, que significa Mobile Shell Es una aplicación de línea de comandos, que se utiliza para conectarse al servidor desde una computadora cliente, a través de Internet....
+La entrada Mosh, un ssh más eficiente en Linux se publicó primero en ochobitshacenunbyte.
+ +
+
+
+
+ The Internet Book Baron
+The History of the Web 06 04 2021
+This week I have something a bit different, written by longtime newsletter author Ernie Smith, best known for his history […]
+The post The Internet Book Baron appeared first on The History of the Web.
+ +
+
+ Cómo montar un SonarQube en Cloud que nos sirva de Spike (Parte 1)
+En Mi Local Funciona 06 04 2021
+
+
+
+
+ State of Clojure 2021 Results
+Clojure News 06 04 2021
+
+
+
+
+
+
+While a challenging year overall, 2020 was another good year for Clojure and its ecosystem. One big newsworthy item was that Cognitect joined Nubank, the world’s largest independent digital bank, to reinvent financial services across Latin America. The news was well received, and the general sentiment is summarized by a comment left by one of the survey respondents:
+
+
++Great to see the Nubank acquisition of Cognitect. I think this has done wonders to bolster confidence in Clojure and Datomic for the long term. Also the subsequent support of open source developers sends a very positive message, and directly supports a healthy and robust ecosystem. ++
+— anonymous survey respondent
+
+
+
+Indeed Ed Wible, the co-founder of Nubank talked about Nubank’s commitment to supporting and growing Clojure (and Datomic) into the future.
+
+
+In this post I’ll outline a few of the more salient points shown in the 2021 survey. Specifically, I’ll touch on the use of Clojure in production, the use of Clojure for start-ups, and how Clojure helps programmers and organizations to move quickly and confidently. As an added bonus I’ll highlight some of the amazing projects and people making the Clojure community strong.
+
+
+Clojure in Production
+
+
+
+
+Continuing the trend from last year, Clojure has seen growth in large companies (i.e. those having 100-1000 employees).
+
+
+
+
+
+
+
+
+Nubank currently employs approximately 700 (at the time of writing) Clojure programmers, and Nubank is just one prominent example of the many banks, mortgage companies, and financial services companies using Clojure today, accounting for 22% (and growing) of the Clojure job market as reported by survey respondents. The survey shows healthy gains in the healthcare and retail markets as well.
+
+
+
+
+
+
+
+
+Having said all of that, just where are Clojure projects deployed in production systems? Interestingly, the survey shows some nice growth in the way of public cloud and serverless deployments. The trends for AWS indicate that the cloud market is booming and so it’s natural that the general increase for that segment would show specifically for Clojure deployments as well.
+
+
+Clojure (still) for Start-ups
+
+
+
+
+While more large companies are adopting Clojure than ever, the sweet spot is still the smaller companies of less than 100 employees.
+
+
+
+
+
+
+
+
+The reasons that start-ups choose Clojure are many and variegated:
+
+
+-
+
-
+
Leverage - small effort, big result
+
+ -
+
Ready access to large existing ecosystems - Java, JavaScript, .NET
+
+ -
+
Scalable base - grow from PoC, to MVP, to production systems at scale
+
+ -
+
Moving fast - discussed in the next section
+
+
+
+One exciting start-up of note in the Clojure ecosystem is Roam Research. Roam’s flagship product is an online note-taking tool that is designed to augment the human mind in building a set of notes that allow deep connectivity and discoverability. The enthusiasm for Roam is palpable and it’ll be fun to watch them grow.
+
+
+Clojure for Moving Fast
+
+
+
+
+Most survey respondents reported that they came to Clojure from the Java programming language. The fact that both languages run on the same virtual machine certainly helps smooth the path from Java to Clojure. However, many other advantages allow Clojure programmers a greater flexibility and agility in their day to day work lives using Clojure.
+
+
+
+
+
+
+
+
+First, Clojure programmers value a functional style of programming facilitating a separation of data and process. Coupled with its suite of immutable data structures, Clojure applications are often built as pipelines of data transformation functions that can be composed to implement higher-level business concepts in software. As a dialect of Lisp, Clojure provides an interactive programming environment called the REPL (Read, Eval, Print, Loop). The REPL fosters exploratory programming, allowing Clojure programmers to interactively develop solutions to sticky programming problems using a tight feedback loop. Indeed, the confluence of the REPL, immutable data structures, and functional programming allows for a development process light on ceremony, allowing programmers to focus on the problem at hand rather than the complexities foisted on them by their programming language.
+
+
+
+
+ The Clojure Ecosystem
+
+
+
+
+Finally, Clojure would have never grown to its current size without the help of countless developers, technical writers, and big thinkers along the way. The appreciation for the amazing Clojure community is palpable within Nubank and this appreciation is increasingly being expressed as open source project funding. I’d like to close this year’s post by highlighting a number of the community leaders mentioned in the survey responses.
+
+
+-
+
-
+
Bozhidar Batsov for continuing to improve Clojure tooling ecosystem.
+
+ -
+
Arne Brasseur - Kaocha is superb and his educational skills fantastic.
+
+ -
+
Everything Michiel Borkent aka borkdude touches is awesome!
+
+ -
+
Sean Corfield because he is always helpful and polite, and writes excellent documentation for important libraries.
+
+ -
+
Michael Fikes for being enthusiastic, engaging, and inspirational, and approachable.
+
+ -
+
Thomas Heller has made an amazing tool in shadow-cljs.
+
+ -
+
(Daniel) Higginbotham, because he made me laugh hundreds of times while introducing me to Clojure.
+
+ -
+
Tony Kay and contributors of Fulcro for providing a comprehensive solution to client-server state management.
+
+ -
+
Gene Kim for … unabashed love of the language, and for helping spread the good word.
+
+ -
+
London Clojurians - the online talks in the past year have been amazing.
+
+ -
+
Tiago Luchini, Hodur creator.
+
+ -
+
Carin Meier for her progressiveness: for advancing the state of the art in machine learning, and her contributions to visibility and representation in the community.
+
+ -
+
David Nolen is generous with explanations, direct, genuine, and never condescending or judgmental.
+
+ -
+
Eric Normand, as he provides great content for beginners.
+
+ -
+
Michael Nygard for architecture insights.
+
+ -
+
Dmitri Sotnikov for making web dev in Clojure accessible to the masses.
+
+ -
+
Peter Taoussanis - Nice, simple and complete libraries.
+
+
+
+There are so many more who deserve praise and recognition so in the words of one of the survey respondents:
+
+
++Clojure literally changed my life for the better. I am eternally grateful for the humans behind it. ++
+— anonymous respondent
+
+
+
+We too are grateful for everyone involved in the Clojure community and we hope to see a continuance and growth in support for those members of the community who work so hard and devote their valuable time to help Clojure and its ecosystem thrive.
+
+ 
+
+
+ Days
+MonkeyUser 06 04 2021
+
+
+
+
+ Set up Tailwind CSS JIT in a Rails project to compile styles 20x faster
+Martian Chronicles, Evil Martians’ team blog 06 04 2021
+
+
+ Building an ultimate writing machine from Sublime Text
+tonsky.me 06 04 2021
+
+
+ Auto build and publish emacs org configuration as a website
+(ノ°Д°）ノ︵ ┻━┻ 04 04 2021
+
+ 
+
+
+ Auto build and publish emacs org configuration as a website
+(ノ°Д°）ノ︵ ┻━┻ 04 04 2021
+
+Having our emacs configuration in an org file is great, it allow us to have it more organized and easy to read, but org files have more features and one of them is the ability to be exported to different formats like HTML, PDF, markdown and so on. So what if we export our emacs configuration to HTML and then publish it in a website? 🤯
+It probably doesn't have any real utility but it would be nice to have a exclusive web page to show our emacs config to our friends :)
++We can do this in two ways:
+-
+
-
+
Manually, we can export the org file using the regular exportation feature of
+org-modeand then upload the resulting HTML somewhere
+ -
+
Automatically, our configuration will be rendered and published into a website every time we push some changes to our
+dotfilesrepository
+
Let's define what we need to do to have the automatic way:
+-
+
-
+
Have a script that render our org config file
+
+ -
+
Run this script in a CI so it can be run every time we push some changes
+
+ -
+
Push the rendered HTML to an extra repository
+
+ -
+
Activate Github Pages in the extra repository, so we can have an url where we can see the resulting website
+
+
Let's assume we have this structure in our dotfiles repository:
+
+
+├── emacs
+│ ├── config.org
+│ └── init.el
+└── scripts
+This is a "regular" structure for a dotfiles repository, the extra scripts folder will be used later. Now let's deep into how it will work.
+
++Automate the org file rendering +
+
+
+
+We need to create to files and put them inside scripts folder:
-
+
-
+
+render-emacs-config-to-html.sh, this will render our config file and place the resulting HTML file insidescripts/output/index.html
+ -
+
+org-render-html-minimal.el, this is a minimal config file to be able to render org into html, it load the required packages and make some basic configuration
+
Let's explore first scripts/org-render-html-minimal.el
+
+
+(require 'package)
+
+(setq package-archives '(("gnu" . "https://elpa.gnu.org/packages/")
+ ("melpa" . "https://melpa.org/packages/")))
+
+(package-initialize)
+
+(package-refresh-contents)
+
+;; this is required to highlight code blocks properly
+(package-install 'htmlize)
+
+(require 'org)
+
+(require 'htmlize)
+
+;; For some reason the default value `inline-css' doesn't apply syntax highlighting correctly
+;; in the resulting html file so we need to change the value to `css'
+(setq org-html-htmlize-output-type 'css)
+To export code blocks correctly we need the package htmlize, this package is available in MELPA so we need to configure MELPA and then install it from there.
+Now let's check scripts/render-emacs-config-to-html.sh
+
+
+#!/bin/sh
+
+# read the docs based theme
+echo "#+SETUPFILE: https://raw.githubusercontent.com/fniessen/org-html-themes/master/org/theme-readtheorg.setup" > index.org
+cat ../emacs/config.org >> index.org
+
+emacs index.org --batch -Q --load org-render-html-minimal.el -f org-html-export-to-html --kill
+
+# output will be the directory uploaded to the render repository so we have to put all the resulting files inside that folder
+mkdir output
+mv index.html output/+What are we doing here?
+
+We basically create a new org file called index.org and put a setup configuration file in it. You can avoid this step if you put this line directly in your config file, in this case we're using one of the themes available in this repository, there is more themes available in this other repository so you can choose the one you like the most.
+Now we need to run emacs with our previously defined configuration org-render-html-minimal.el and tell it to render our index.org.
+And finally we put the resulting index.html inside output folder. This folder will be used later.
+
+
+ +Using Github actions to build and publish the rendered config +
+
+
++We're going to use a Github action called push-directory-to-another-repository, this action allow us to commit and push changes in another repository. Some configuration is required to use this action:
+
+
++Create a extra repository +
+
+
+
+This extra repository will be used to host our rendered config file, in my case this repository is erickgnavar/emacs-config, we also need to activate Github Pages in this repository and set it up to use master branch
+
+The url generated, erickgnavar.github.io/emacs-config in my case, is where our rendered config file will be published.
+
+
++Create a personal token +
+
+
+
+To be able to push changes into the new repository we have to create a personal access token, this can be made in account settings, this token should have the repo scoped activated.
+
+
++Configure a secret variable in our dotfiles repository +
+
+
+
+The Github action needs a secret variable called API_TOKEN_GITHUB, this variable allow the action to push changes into the new repository, we can create it by going to repository/settings/secrets/New repository secret
+
+
++Configure Github action config file +
+
+
+
+Finally we have to create a file .github/workflows/ci.yml with the following content:
+
+
+name: CI
+
+on:
+ push:
+ branches: [ master ]
+
+jobs:
+ build-emacs-config-page:
+ runs-on: ubuntu-latest
+ container: alpine:3.13.4
+ steps:
+ - uses: actions/checkout@v2
+ - name: Install emacs
+ run: apk --update add emacs
+ - name: Render config into html
+ run: cd scripts && sh render-emacs-config-to-html.sh
+ - name: Pushes to destination repository
+ uses: cpina/github-action-push-to-another-repository@cp_instead_of_deleting
+ env:
+ API_TOKEN_GITHUB: ${{ secrets.API_TOKEN_GITHUB }}
+ with:
+ source-directory: 'scripts/output'
+ destination-github-username: 'YOUR_GITHUB_USERNAME'
+ destination-repository-name: 'YOUR_NEW_REPOSITORY_NAME'
+ user-email: bot@emacs.bot+This action config file make some things:
+-
+
-
+
Install emacs so we can run it to render our config file
+
+ -
+
Render our config file using the script
+render-emacs-config-to-html.shwe previously defined
+ -
+
Take the content of
+scripts/output, commit and push it into our destination repository, this is why we need to move the resulting HTML file intooutputfolder
+ -
+
And finally it calls
+github-action-push-to-another-repositoryaction which will do all thegitstuff required to push the changes
+
Now every time we push changes to our dotfiles repository this action will push the rendered config file to our destination repository, the commits will look like this:
+
+And when we enter to the url generated from Github pages, erickgnavar.github.io/emacs-config in my case, we can see our configuration rendered:
+
+
+Enjoy 🎉
+
+
+ Easy deploy of docker based projects
+(ノ°Д°）ノ︵ ┻━┻ 03 04 2021
+
+
+ Easy deploy of docker based projects
+(ノ°Д°）ノ︵ ┻━┻ 03 04 2021
+
+I have a personal server where I run some projects, some of them written in python, elixir and other technologies so having to deal with specific installation of any of these technologies is not an ideal workflow, to fix this I use docker and all of them are deployed using docker-compose, they're connected to a single PostgreSQL server and they're behind the same web server.
+Running all of these projects in this way it's easier to maintain and in case something happens with the server I can re deploy everything in a easy way. Let's take a look to these tools and how they work together.
++Let's assume we have the following requirements:
+-
+
-
+
Deploy a django application
+
+ -
+
Deploy a phoenix application
+
+ -
+
Each application needs a PostgreSQL database
+
+ -
+
Both applications should be behind a web server and being accessed over HTTPS
+
+ -
+
All of these should run in the same server
+
+
To solve this we're going to:
+-
+
-
+
Set up a linux server
+
+ -
+
Install PostgreSQL
+
+ -
+
Configure a web server which will handle incoming traffic and SSL termination
+
+ -
+
Run our applications inside Docker containers
+
+
+
++Setting up a server +
+
+
++If you already have a server you can skip this section.
++We first need a server which can run docker, most linux distros can be used for this but in this case we'll be using Ubuntu Server, if you don't have a server yet you can use any of these referral links to get some credit when you create your account:
+-
+
-
+
Digital Ocean this will get you $100 on credits to be used in 2 months
+
+ -
+
Hetzner this will get you 20€ on credits, this provider has cheaper prices than Digital Ocean but it only have data centers in Europe
+
+ -
+
Linode this will get you $100 on credits to be used in 2 months
+
+
Once you get a server it's recommended to make some basic configurations like updating packages, setup a firewall, etc. You can follow this Linode guide to secure your server.
++After that you need to install docker, to do that you can follow the official documentation, this have specific instructions for you linux distribution.
+
+Once we have docker and docker-compose installed we can follow this guide.
+
++Installing PostgreSQL in our host machine +
+
+
++We're going to use a unique instance of PostgreSQL installed in the host machine, this way we can share the resources used by PostgreSQL with all the applications that we're going to deploy, we just need to create new users and databases for each one of the applications.
++First let's install PostgreSQL with:
+
+
+
+sudo apt install postgresql-server
+We need to login with postgres user so we can be able to enter to a psql session. We can do it with:
+
+
+sudo su - postgres
+Now we can open a psql session and create the databases and users for our applications:
+
+
+postgres=# CREATE USER django WITH ENCRYPTED PASSWORD 'secret';
+
+postgres=# CREATE DATABASE django WITH OWNER django;+And we do the same for our phoenix application:
+
+
+
+postgres=# CREATE USER phoenix WITH ENCRYPTED PASSWORD 'secret';
+
+postgres=# CREATE DATABASE phoenix WITH OWNER phoenix;
+
++Configuring Caddy as a reverse proxy +
+
+
++Caddy is a "new" web server written in Go that have 2 main features that make it a good option for simpler deployments:
+-
+
-
+
Simpler configuration file
+
+ -
+
Free auto configured SSL certificates, using Let's Encrypt service, and automatic renewals
+
+
If we were using for example Nginx we have to deal with HTTPS certificates by ourselves, installing certbot, and also have to configure some way to renew the certificates, Let's Encrypt issues certificates that expire after 3 months.
+
+Let's define our domains django.domain.com and phoenix.domain.com which will send traffic to their specific applications.
+Our django application needs that Caddy serves the static files so we define file_server option and tell caddy where are our static files, we also tell Caddy to send the traffic to port 8000 where our application is listening.
+
+
+django.domain.com {
+ root * /opt/django
+
+ @notStatic {
+ not path /static/*
+ }
+
+ reverse_proxy @notStatic localhost:8000
+ file_server
+}
+Our phoenix application will serve static files by itself so we just need to define the reverse_proxy directive to be able to send the traffic to port 4000
+
+
+phoenix.domain.com {
+ reverse_proxy localhost:4000
+}
+Now when we reload our caddy server with sudo systemctl reload caddy it will get the SSL certificates and internally will check if they still valid, otherwise it will renew them.
+
++Running our projects with docker-compose +
+
+
+
+Docker compose is a tool that allow us to define different docker services in a easier way using a yaml file.
+We're going to configure our two projects using docker-compose but we first need their docker images so let's build them.
+Let's clone our projects(both are in the same repository, just in different folders), build the images and then publish them on a registry.
++This can be made in a separate machine because once the images are pushed to a remote registry they can be downloaded in our server.
+
+
+
+cd simple-django-project-with-docker
+docker build -t registry.mycompany.com/django:v1 .
+docker push registry.mycompany.com/django:v1
+
+
+cd simple-phoenix-project-with-docker
+docker build -t registry.mycompany.com/phoenix:v1 .
+docker push registry.mycompany.com/phoenix:v1+You can use docker hub to push your images or use Gitlab registry in case you want free private images.
+
+
++Django application +
+
+
+
+Let's create a folder in /opt/django and put the following code into a docker-compose.yml file.
+
+
+version: "2"
+services:
+ web:
+ image: registry.mycompany.com/django:v1
+ restart: always
+ network_mode: host
+ environment:
+ ALLOWED_HOSTS: "django.domain.com"
+ DEBUG: "0"
+ DATABASE_URL: "postgres://django:secret@localhost:5432/django"
+ DJANGO_SETTINGS_MODULE: "config.settings"
+ SECRET_KEY: "a 32 long secret key"
+ volumes:
+ - ./static:/app/static
+ ports:
+ - "127.0.0.1:8000:8000"
+The static folder will be used by Caddy to server static files.
+
++Phoenix application +
+
+
+
+Now for our phoenix application let's create a folder /opt/phoenix and put the following code into a docker-compose.yml file.
+
+
+version: "2"
+services:
+ web:
+ image: registry.mycompany.com/phoenix:v1
+ restart: always
+ network_mode: host
+ environment:
+ DATABASE_URL: "postgres://phoenix:secret@localhost:5432/phoenix"
+ MIX_ENV: prod
+ HOST: "phoenix.domain.com"
+ SECRET_KEY_BASE: "a 32 long secret key"
+ ports:
+ - "127.0.0.1:4000:4000"
+Because we're running PostgreSQL in our host machine instead of a docker container we have to use network_mode: host, this allow us to access postgres just pointing to localhost.
+
++Deploying our projects +
+
+
+
+Once we have the docker-compose.yml files configured we can go inside each project folder and run:
+
+
+docker-compose up -d+For the django application we also have to run these commands, these are specific of django deployment process.
+
+
+
+# Run database migrations
+docker-compose exec -T web python manage.py migrate
+
+# Collect all static files and place them in our STATIC_ROOT folder which will be served by Caddy
+docker-compose exec -T web python manage.py collectstatic --no-input
+
++Deploying new changes +
+
+
++Because we're using docker, when we need to update changes we just need to update their Docker images and restart their services. Some technologies can have differences in their deployment process but the basic idea is the same.
++Let's see how it could be for our two example applications.
+
+
++Django application +
+
+
+
+When we update a django application we need to run some extra commands like migrate, collectstatic, etc. We can follow these steps to run them inside the docker container:
+
+
+docker pull NEW_DJANGO_IMAGE
+
+sed -i "s/image.*/image:\ NEW_DJANGO_IMAGE/" docker-compose.yml
+
+docker-compose up -d --force-recreate
+
+docker-compose exec -T web python manage.py migrate
+
+docker-compose exec -T web python manage.py collectstatic --no-input
+We're pulling the new image from our registry, updating the image value in our docker-compose.yml file, restart the service (it will use the new image now) and then we can execute migrate and collectstatic commands
+
++Phoenix application +
+
+
++For the phoenix application we're going to follow almost the same process with just one difference, we don't need to run migrations in a separate step because they will run when the application starts, this is defined in the phoenix docker image itself.
+
+So we just need to pull the new image, update it in docker-compose.yml file and then restart the service, the final script will be:
+
+
+docker pull NEW_PHOENIX_IMAGE
+
+sed -i "s/image.*/image:\ NEW_PHOENIX_IMAGE/" docker-compose.yml
+
+docker-compose up -d --force-recreate
+
+
+ +Conclusion +
+
+
++Having a central PostgreSQL instance and a central web server(Caddy), both in the host machine instead of inside a container allow us to manage them easily and also allow us to share these common services alongside the many applications that we are running in our server.
+
+
+ Solving Advent of Code 2020 in under a second
+Danny van Kooten 01 04 2021
+Advent of Code is an annual event of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language.
+ +Last year (AoC 2019), I participated for the first time and used Rust as my language of choice.
+ +This year, albeit a few months after the event actually occurred, I participated again and used C as my weapon of choice. (And yes, I did hurt myself in the process.)
+ +I set out with two goals in mind:
+ +-
+
- To finish all challenges within a single month. +
- To solve them all in under 1 second of runtime (on a single CPU core). +
For this last goal I was inspired by Tim Visee who did a really great write-up of some of the tricks he used to efficiently solve this year’s challenges. It sounded like a really fun thing to do and I was already well underway for such a thing anyway.
+ +Two weeks later, iet ies done! Total runtime is 548 ms on my laptop, so I’m quite pleased with the results.
+ +I could probably squeeze out a few more miliseconds here and there, but I see no options for making the 2 bottlenecks (day 15 and day 23) run any faster (except for throwing more hardware at it).
+ +The code is on GitHub here: dannyvankooten/advent-of-code-2020
+ +To be honest, finishing all challenges was harder than getting them all to run in under a second. I really enjoy optimising code for performance and trying out different algorithms.
+ +Things I learned:
+ +-
+
- You can represent a hexagonal grid in a 2D array by simplify shifting every odd column or row (day 24). +
- Linear probing is a much simpler way to deal with hash collissions than a linked list and results in less cache misses because the values can reside in contiguous memory locations. +
- To check neighbors or directions in a 2D grid, it’s a lot more concise to keep an array of
ΔxandΔyvalues versus writing out all the various directions in a separate loop.
+ - You can’t brute force your way out of everything. Sometimes, math is required to get decent performance. Specifically, Chinese Remainder Theorem for day 13 and any of the algorithms for finding the discrete log for day 25. +
- Tooling! I wouldn’t want to write C without Valgrind and Gprof. Cachegrind can be useful too. +
- When an array gets really sparse, it can be more efficient to use a hashmap despite the added overhead (day 15). +
- In loops, it can be really useful to add a call to
getc(stdin)combined withprintfdebugging to allow stepping through the loop. Especially if you haven’t yet taken the time to learn GDB well enough, like me.
+
+ + + +
The task was to find the product of the three entries in the puzzle input that sum to 2020. Since most numbers in the input were well over half that, it made sense to first sort the input in ascending order before starting our loops.
+ ++ + + +
Day 2 was fairly straightforward, so I won’t go into any details on it.
+ ++ + + +
The puzzle input is a 2D grid of tree positions. We’re then tasked with counting the number of trees for given slopes. I just looped over the 2D array multiple times, each time incrementing the row- and column indices with the given slopes.
+ ++ + + +
The input consisted of several “passports” with their field names and values in a random order. Each field had restrictions on what a valid value for that field looked like.
+ +My solution iterates over each passport in the input, marks each field (except the one that was to be ignored) as valid (1) or invalid (0) in an array and then uses memcmp to check whether the passport is valid or not.
There is a possible optimization by skipping forward to the next passport whenever any of the required fields is invalid, but since the runtime is already so low I did not find this worth the time.
+ ++ + + +
My solution decodes each input line into a row and column, turns these into a seat ID and finds the highest seat ID. At the same tame it toggles a boolean value in a 2D array to keep track of all occupied seats.
+ +It then iterates over this array while skipping the first few rows to find the first seat that is empty.
+ ++ + + +
For day 6 I create two arrays of size 26 to keep track of user answers and group answers respectively. At the end of each line I AND the two arrays, so I have an array filled with 1’s for the answers that were answered by every user in a group. Counting the 1 values in the group answers array gets us the number of questions answered by everyone in a group.
+ +
Day 7 / code / runtime: 4144 μs
+ +Day 7 was the ideal candidate for a hashmap, since we have to do a ton of lookups by the name of a bag. Since I had just read Ben Hoyt’s post on how to implement a hash table in C, I decided to give his implementation a try.
+ +Sadly I don’t have the linear search version in version control, as I would like to see what difference it made, but IIRC it was huge given that there are 594 bags in my input.
+ ++ +
Day 8 / code / runtime: 105 μs
+ +Day 8 reminded me of the bytecode interpreter I wrote last year, so I really enjoyed this one. To detect the infinite loop I kept changing a single JUMP instruction to a NOOP until we reached the end of the program without repeating an instruction.
+ ++ + + +
Dynamic programming! It took me a while to realise this though. For part 2 I go over a sorted array of adapter joltages and then count how many of the previous adapters it can connect to, adding the sum of options to get to that previous adapter to the one we’re looking at.
+ ++ +
Day 11 / code / runtime: 2163 μs
+ +A 2D square-grid problem where we have to look at all 8 neighbors for every point. I optimized this solution by keeping a list of neighbor indices for each seat, so these do not have to be recomputed on every transmutation.
+ +Another optimization is to keep a list of seats to check and remove a seat from this list once it reached its permanent state:
+ +-
+
- If a seat is occupied and has less than 5 occupied neighbors, it is permanently occupied. +
- If a seat has a permanently occupied neighboring seat, it is permanently empty. +
+ +
Day 12 / code / runtime: 61 μs
+ +A ship that moves towards a waypoint positioned relative to the ship, according to directions in the puzzle input. I didn’t optimize this solution that much since the straightforward approach was already plenty fast.
+ +I used sin() and cos() for rotating the waypoint, but since the rotation amount is fixed to a multiple of 90 I could get rid of these.
+ + + +
This day required the Chinese Remainder Theorem to get done in a reasonable amount of time. Sadly I was not able to come up with this myself, but I saw a mention of it after getting stuck on my brute-force approach.
+ ++ +
Day 14 / code / runtime: 1334 μs
+ +Updating “memory addresses” with certain values from the puzzle input after applying a (changing) mask to the address. Since addresses were so large and wouldn’t fit in an array, I wrote a simple hashmap with integer keys and values.
+ +To make sure the hashed key value is within the bounds of the backing array, I made sure capacity itself was a power of 2 and then used a bitwise & on the capacity - 1. This is a lot faster than using the modulo operator.
+ +
Day 15 / code / runtime: 360147 μs (360 ms)
+ +Today would have made the 1-second goal impossible without good enough hardware and a language that compiles to machine code. The solution is fairly straightforward and doesn’t leave much room for optimization.
+ +For values lower than ~500K, I used an array to look-up the previous position of a number in constant time.
Since values larger than 500K were further apart (sparse), I used an optimized hashmap implementation for these values to store the previous positions. It uses a really limited amount (< 10) of linear probing attempts to prevent spending too much time on values that have not been seen before.
I used a lookup array that stores the previous index of a number. The array was allocated using mmap with 2 MB “huge” page sizes in combination with a bitset that is checked before even indexing into the array. This shaved off another 100ms compared to the array + hashmap approach.
+ +
Day 16 / code / runtime: 183 μs
+ +Today we had to parse a bunch of rules and find which values corresponded to which rule. We could deduce the position of each field by first creating a list of possible options and then picking the only available option and removing it from all other fields, repeating that latter part until we know the position for each field.
+ +Today’s optimization was to simply ensure we’re breaking out of each loop or skipping to the next iteration as soon as possible.
+ ++ +
Day 17 / code / runtime: 2136 μs
+ +Day 17 was another game of life inspired challenge, but using a 4D grid.
+ +The largest performance gain came from precomputing the neighbor count by looping over the active tiles and then adding 1 to each neighbor. This saves a ton of iterations versus doing it the other way around.
+ ++ +
Day 18 / code / runtime: 449 μs
+ +For day 18 we got to write a simple math parser with different operator precedence than what we’re used to in human math. I used what I learned from the interpreterbook.com to implement an operator precedence parser.
+ ++ +
Day 19 / code / runtime: 516 μs
+ +I forgot the specifics of day 19. It was about implementing a form of regex and preventing infinite recursion. All I recall is that I did a simple recursion check on the two rules that caused the infinite recursion, and it worked…
+ ++ +
Day 20 / code / runtime: 877 μs
+ +Day 20 was about putting together an image from various tiles that had to be rotated and flipped into the correct orientation in order to fit together. This was the challenge that cost me the most time, but also probably the one I enjoyed the most.
+ +My solution simply started with the first tile in the top-left corner in the image and then fitted any of the other tiles on any of its edges until all tiles were in the image. Instead of rotating the entire tile and then checking whether it fit, I only compared the edges of the tile and only rotated or flipped it when a match was found.
+ +If another tile fitted on the northern or western edge of the starting tile, I shifted all the tile in the image. Another option was to first find a corner tile and then work from there, but this approach proved to be faster.
+ ++ +
Day 21 / code / runtime: 276 μs
+ +Day 21 resembled day 16 in that we could decude which ingredients contained an allergen by repeatedly picking the only available option until we were done.
+ ++ +
Day 22 / code / runtime: 104 μs
+ +Today was fun! A game of cards with recursion.
+ +Pre-allocating enough memory for at most 50 games gave a slight performance increase. The biggest improvement came from not recursing into a sub-game (and all of its descedentants) when the sub-game started with player 1 holding the highest card.
+ +Because of the special rule this meant that player 1 would eventually emerge as the winner, so we could declare him winner right away and save on an awful lot of recursion.
+ ++ +
Day 23 / code / runtime: 172981 μs (173 ms)
+ +A slow day today with not much room for making it run faster. I used an array where the value simply contained the next cup, thus resembling a singly linked list. This meant just changing 2 values on every iteration, 10 million times…
+ +Like for day 15, I used 2 MB page sizes again. This resulted in a 22% performance improvement (51 ms faster) than using the default 4 kB page size.
+ ++ +
Day 24 / code / runtime: 3102 μs
+ +Another 2D grid problem but using a hexagonal grid, flipping to either black or white based on directions from the puzzle input. Part 2 introduced a form of game of life again. I re-used the same optimizations from before, pre-computing neighbor counts.
+ +One more thing was to allocate a grid large enough to hold our entire “infinite” grid, but only iterating over the values neighboring any black tile.
+ +Whenever a tile was flipped to black, I extended the grid bounds to iterate over and updated the neighbor count for each of that tile’s neighbors.
+ ++ +
Day 25 / code / runtime: 58 μs
+ +Day 25 involved finding the discrete log, so I used the Baby-Step-Giant-Step algorithm while re-using my integer hashmap from an earlier day. This turned out to be really fast, clocking it at just 58 microseconds of runtime.
+ +
+
+ Using compilation mode to run all the things
+(ノ°Д°）ノ︵ ┻━┻ 01 04 2021
+
+ 
+
+
+ Using compilation mode to run all the things
+(ノ°Д°）ノ︵ ┻━┻ 01 04 2021
++Compilation mode is a major mode that allow us to run a command and see its output result in a special buffer, this resulting buffer show the errors and allow us to navigate through them, you can check the documentation for more details.
++It's a "simple mode" but it can be used for many things like compile and run a program, run tests, and so on.
+
+
++Usage +
+
+
+
+
++Interactive +
+
+
+
+compile is an interactive function so we can call it with M-x compile and enter the command we want to execute.
+In the following example we're compiling this blog using hugo binary:
+
+
+
++From code +
+
+
+
+compile is a emacs-lisp function so we call it from our code, we just need to take care about the default-directory when we call it, for example if we call it from lib/hello.ex buffer, default-directory will be lib and in some cases we want to use our project root, or a different directory, to run our command.
+To fix this we need to setup default-directory before we call compile, for example let's build a custom function to run hlint in our entire project and then show its results in a compilation buffer:
+
+
+(defun my/run-hlint ()
+ "Run hlint over the current project."
+ (interactive)
+ (let ((default-directory (projectile-project-root)))
+ (compile "hlint .")))
+In this case we're setting up default-directory with our project root (using projectile to get the root) and then when we call compile it will take default-directory correctly.
+
++Some tweaks +
+
+
+
+These modifications to default behaviour of compilation-mode should be made after the mode was loaded so we need to use with-eval-after-load otherwise these changes won't be applied correctly.
+
++Evil-mode +
+
+
+
+The compilation buffer has some preset key bindings that conflict with evil-mode, for example when we press g in a compilation buffer this will re-run the command, but this key binding is also used by evil-mode, to fix this we can disable the default key binding with:
+
+
+(with-eval-after-load 'compile
+ (define-key compilation-mode-map (kbd "g") nil)
+ (define-key compilation-mode-map (kbd "r") 'recompile)
+ (define-key compilation-mode-map (kbd "h") nil))
+In this case h key binding is also disabled (also used by evil) and r is remapped to recompile for easy access now that we disabled g default key binding.
+
++Follow compilation output +
+
+
+
+By default compilation-mode doesn't follow the output of the command so if our command result has a large output we'll need to scroll manually, to fix this we can change compilation-scroll-output to t
+
+
+(with-eval-after-load 'compile
+ ;; set cursor to follow compilation output
+ (setq compilation-scroll-output t))
+
++Enable ANSI colors +
+
+
+
+Some tools show results with colors for easy reading but compilation-mode won't show them by default, you can make them look better with:
+
+
+(require 'ansi-color)
+
+(defun colorize-compilation-buffer ()
+ (let ((inhibit-read-only t))
+ (ansi-color-apply-on-region (point-min) (point-max))))
+
+(add-hook 'compilation-filter-hook 'colorize-compilation-buffer)+This was taken from this Stack Overflow answer
+
+
++Re run compilation from another buffer +
+
+
+
+When we're making changes in our code we want to re-run our compilation process right after we save the changes but to do this we have to move to the compilation buffer to be able to re-run the compilation, a better approach to do this could be just call recompile by using a key binding, I use evil-leader to make this:
+
+
+(evil-leader/set-key "R" 'recompile)
+
+But it can be attached to any key binding, for example:
+
+
+
+(global-set-key (kbd "C-c C-r") 'recompile)
+
++Bonus: run parrot mode animation when a compilation is successful +
+
+
+
+I configured parrot-mode to animate the little parrot every time the compilation process is a success, to make this we need a small function that check if it was a success and then we need to attach it to 'compilation-finish-functions, this is a variable defined in compilation-mode.
+
+
+(defun my/parrot-animate-when-compile-success (buffer result)
+ (if (string-match "^finished" result)
+ (parrot-start-animation)))
+
+(use-package parrot
+ :ensure t
+ :config
+ (parrot-mode)
+ (add-to-list 'compilation-finish-functions 'my/parrot-animate-when-compile-success))
+
+
+ +Conclusion +
+
+
+
+As we can see compilation-mode is a simple but powerful mode that allow us to build our own tools, we can create an automatic build system in case there is not something already existing for the technology we're using or if we just want to run some tasks in an easier way.
+
+
+
+ 3 ejemplos básicos de Terraform sobre AWS
+República Web 30 03 2021
+Para este episodio de Informe Nube, David y Antony vuelven con Terraform sobre AWS para explicar tres ejemplos básicos. Este episodio continúa el anterior sobre Terraform en AWS y se puede seguir también desde el canal de YouTube de Cursos de Desarrollo.
+ + + +-
+
- Cómo crear las credenciales y configurar el cli de AWS +
- Cómo crear una máquina virtual en AWS EC2 con acceso SSH y Clave SSH +
- Cómo crear un servidor Web Nginx en EC2 con soporte de Elastic IP y Volumen de Datos asociad +
- ómo crear un Cluster de Kubernetes EKS en AWS + +
No dudes en conectar con David y con Antony para sugerirles nuevos episodios sobre cloud y tecnologías de servidor.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
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+
+
+ Introducing TestParameterInjector: A JUnit4 parameterized test runner
+Google Open Source Blog 30 03 2021
+
+
+ Statement from the FSF board of directors meeting on March 29, 2021
+FSF News 30 03 2021
+
+
+ Acelerando los desarrollos con contenedores : SonarQube
+En Mi Local Funciona 30 03 2021
+
+ 
+
+
+ Task Description vs Effort
+MonkeyUser 30 03 2021
+
+
+ Student applications for Google Summer of Code 2021 are now open!
+Google Open Source Blog 29 03 2021
+
+
+
+
+ March 2021 Weblog: Trusting in the Standard
+The History of the Web 29 03 2021
+A look at the work that standards makes possible, and the kinds of hypertext that were never fully realized
+The post March 2021 Weblog: Trusting in the Standard appeared first on The History of the Web.
+ +
+
+ Welcoming Ian Kelling to staff seat on FSF's board of directors
+FSF News 29 03 2021
+
+
+ Font size is useless; let’s fix it
+tonsky.me 29 03 2021
+
+
+ Updated Debian 10: 10.9 released
+Debian News 27 03 2021
+buster). +This point release mainly adds corrections for security issues, +along with a few adjustments for serious problems. Security advisories +have already been published separately and are referenced where available. + +
+
+ JavaScript: saber si la tecla «Bloq Mayus» está activada
+Bufa 26 03 2021
+
+
+ Instalando Istio en Windows 10
+En Mi Local Funciona 26 03 2021
+
+
+ Update on work to improve governance at the FSF
+FSF News 26 03 2021
+
+
+
+
+ MARCO AURELIO Y LA ADVERSIDAD
+Diario Estoico 25 03 2021
+
+
+ Preliminary board statement on FSF governance
+FSF News 25 03 2021
+
+ 
+
+
+ Lem can now be started as a full featured Lisp REPL
+Lisp journey 24 03 2021
+The Lem editor, which supports +Common Lisp as well as other languages, works by default in the +terminal with a ncurses frontend (it also has an experimental Electron +frontend). It ships a nice Lisp REPL: it has good fuzzy completion, +enough keyboard shortcuts, an interactive debugger, a completion menu, +etc.
+ +It is now possible to run Lem straight in its Lisp REPL. Run it with:
+ +lem --eval "(lem-lisp-mode:start-lisp-repl t)"
+The optional argument (t) was added recently (thanks, @cxxxr) and allows to start the REPL in fullscreen.
Here is it in action:
+ +
The other terminal-based REPL alternatives are:
+ + + +but IMO, they now fall short compared to Lem’s features.
+ +Installation
+ +To install it, see its wiki. In short, do
+ + ros install cxxxr/lem
+or use lem-docker.
+ +To install Roswell, do one of
+ +brew install roswell # macos or linuxbrew
+yay -S roswell
+scoop install roswell # windows
+
+# Debian package:
+curl -sOL `curl -s https://api.github.com/repos/roswell/roswell/releases/latest | jq -r '.assets | .[] | select(.name|test("deb$")) | .browser_download_url'`
+sudo dpkg -i roswell.deb
+See its releases.
+ +Usage (quickref)
+ +Lem has Emacs-like keybindings, as well as a vi emulation (M-x vi-mode). Unfortunately, that is not documented much.
So, to open a file, press C-x C-f (you get the file selection dialog shown above). To save it, it’s C-x C-s.
To switch to the REPL: C-c C-z.
To compile and load a buffer: C-c C-k. To compile a function: C-c C-c.
To switch windows: C-x o. To make a window fullscreen: C-x 1. To split it vertically: C-x 3 and horizontally: C-x 2.
To switch buffers: C-x b.
To run an interactive command: M-x (alt-x).
See this Emacs & Slime cheatsheet to find more: https://lispcookbook.github.io/cl-cookbook/emacs-ide.html#appendix
+ +Lem works out of the box for several programming languages (Python, Rust, Scala…). It also has an HTML mode, a directory mode… Lem needs to be discovered!
+ + + +
+
+ Listening to maintainers for the next phase of Clojurists Together
+News on Clojurists Together 24 03 2021
+
+
+ Emoji under the hood
+tonsky.me 24 03 2021
+
+
+ Handling Text Over Images in CSS
+Ahmad Shadeed Blog 23 03 2021
+
+ 
+
+
+ DENVERCODER9
+MonkeyUser 23 03 2021
+
+
+
+
+ Joining forces on better browser compatibility in 2021
+Microsoft Edge Blog 22 03 2021
+Over the past few years, Microsoft has partnered with a group of browser vendors and other industry stakeholders to identify and address the top sources of web developer pain through initiatives like the Joining forces on better browser compatibility in 2021 appeared first on Microsoft Edge Blog.
+ +
+
+ Free Software Foundation lending aid to support local free software groups
+FSF News 22 03 2021
+
+
+ Hyperreals *R: Ejemplo práctico. Potencias de Fermi-Dirac - Evaluación perezosa en python - Parte 6
+Python Hispano 21 03 2021
+Se llaman potencias de Fermi-Dirac a los números de la forma \(p^{2^k}\),
+ordenados de menor a mayor, donde p es un número primo y k es un número natural.
Vamos a ver cómo crear la sucesión de potencias Fermi-Dirac. Realizaremos las
+siguientes comprobaciones:
potencias: list[int]
+
+potencias[:14] == [2,3,4,5,7,9,11,13,16,17,19,23,25,29]
+potencias[60] == 241
+potencias[10**6] == 15476303
+Estudio previo
+Si sacamos la lista de potencias en función del exponente k tendríamos las
+siguientes sucesiones:
$$
+\begin{align*}
+P_0 &= 2,3,5,7,11,...\\
+P_1 &= 4,9,25,49,121,..\\
+P_2 &= 16,81,625,2401,14641,...\\
+P_3 &= 256,6561,390625,5764801,214358881,815730721,...
+\end{align*}
+$$
+Necesitamos combinar estas sucesiones en una sola. A priori, no sabemos cuántos +elementos vamos a necesitar de cada sucesión. Como máximo, para sacar las +primeras 14 potencias nos basta con los primeros 14 números primos y crear 14 +secuencias, de \(P_0\) a \(P_{13}\), ordenarlos sus elementos en una única lista y +escoger los primeros 14 elementos. Con este proceso habremos calculado 196 +potencias para sólo 14 elementos que necesitamos al final.
+from primes import primes
+
+potencias = sorted(p**2**k for p in primes[:14] for k in range(0, 14))
+print(potencias[:14])
+
+[2, 3, 4, 5, 7, 9, 11, 13, 16, 17, 19, 23, 25, 29]
+Aún en el caso de que tuviéramos algún medio de reducir el número de elementos a +usar de cada secuencia, seguimos sin saber cuántos números primos serán +necesarios. Para sacar los 14 primeros elementos de las potencias de Fermi-Dirac +sólo se necesitaban los 10 primeros números primos.
+Es evidente que una estrategia por fuerza bruta es complicada y termina por +hacer muchos cálculos innecesarios, una complejidad del \(O({n^2})\) no resoluble +con un ordenador normal. Veamos cómo nos puede ayudar la evaluación perezosa.
+Modelos
+Por intentar crear un modelo, intentemos ver las sucesiones como un iterador de iteradores:
+from itertools import count
+
+from primes import primes
+
+potencias = ((p**2**k for p in primes) for k in count())
+Pero el problema con las expresiones generadora es similar al que tienen las +expresiones lambda: carecen de su propia clausura y cualquier variable libre +queda alterada por el entorno donde se evalúan.
+Se puede comprobar el fallo si intentamos extraer dos iteradores:
+p0 = next(potencias)
+p1 = next(potencias)
+next(p1) # --> 4
+next(p0) # --> 4
+next(p0) # --> 9
+El exponente k ha cambiado de valor con el segundo iterador, lo que afecta a
+las potencias del primero. Tenemos que dotar a los iteradores de su propia clausura:
from collections.abc import Iterator
+from itertools import count
+
+from primes import primes
+
+def potencias_gen(k: int) -> Iterator[int]:
+ yield from (p**2**k for p in primes)
+
+potencias = (potencias_gen(k) for k in count())
+Para obtener una única secuencia a partir de este iterador de iteradores en un +único iterador, operación que se conoce como “aplanar la secuencia”.
+Definimos la siguiente función para mezclar dos listas ordenadas:
+# tipo para secuencias ordenadas
+SortedIterator = Iterator[int]
+
+def zipsort(s1: SortedIterator, s2: SortedIterator) -> SortedIterator:
+ x = next(s1)
+ y = next(s2)
+ while True:
+ if x <= y:
+ yield x
+ x = next(s1)
+ else:
+ yield y
+ y = next(s2)
+La función zipsort combina dos listas ordenadas SortedIterator para devolver
+otra lista ordenada SortedIterator. Si quisiéramos combinar tres listas,
+bastaría con volver repetir con zipsort:
zipsort(zipsort(s1, s2), s3)
+En general, podríamos combinar todas las listas de esta manera:
+def flat(iterators: Iterator[SortedIterator]) -> SortedIterator:
+ it1 = next(iterators)
+ it2 = flat(iterators)
+ yield from zipsort(it1, it2)
+
+potencias = flat(potencias_gen(k) for k in count())
+El problema es que se entra en un bucle infinito de llamadas recursivas a flat
+que habrá que evitar.
Si observamos las sucesiones \(P_0\), \(P_1\), \(P_2\),…, el primer elemento de una +sucesión es siempre inferior a cualquier elemento de sucesiones posteriores. +Usando esta propiedad, podemos redefinir nuestra función aplanadora:
+def flat(iterators: Iterator[SortedIterator]) -> SortedIterator:
+ it1 = next(iterators)
+ yield next(it1)
+ yield from zipsort(it1, flat(iterators))
+
+potencias = flat(potencias_gen(k) for k in count())
+La función flat devuelve siempre un elemento antes de invocarse por
+recursividad, suficiente para frenar la cadena de llamadas recursivas. Visto de
+otro modo, se ha convertido la función en perezosa, devolviendo elementos a
+medida que sean necesarios. De todos modos, seguimos limitados por el nivel de
+recursividad en python (~3000 niveles en CPython), aunque no vamos a superar
+este límite en las pruebas1.
Código final
+Descarga: potencias.py
+from collections.abc import Iterator
+from itertools import count
+from typing import TypeVar
+
+from lazyseq import LazySortedSequence
+from primes import primes
+
+
+SortedIterator = Iterator[int]
+
+
+def join(s1: SortedIterator, s2: SortedIterator) -> SortedIterator:
+ x = next(s1)
+ y = next(s2)
+ while True:
+ if x <= y:
+ yield x
+ x = next(s1)
+ else:
+ yield y
+ y = next(s2)
+
+
+def flat(it: Iterator[SortedIterator]) -> SortedIterator:
+ s1 = next(it)
+ yield next(s1)
+ yield from join(s1, flat(it))
+
+
+def mkiter(k):
+ yield from (p ** 2 ** k for p in primes)
+
+potencias = LazySortedSequence(flat(mkiter(k) for k in count()))
+Para las comprobaciones:
+>>> potencias[:14]
+[2, 3, 4, 5, 7, 9, 11, 13, 16, 17, 19, 23, 25, 29]
+>>> potencias[60]
+241
+>>> potencias[10 ** 6]
+15476303
+>>> primes.size
+999432
+Para obtener el elemento \(10^6\) tarda bastante al necesitar obtener casi un +millón de números primos. Una vez obtenidos, el cálculo es bastante rápido.
++
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
ANOTACIONES:
+
+
+
+ +
-
+
-
+
Es posible que en posteriores artículos veamos técnicas para superar las +limitaciones de la recursivad en python. ↩
+
+
+
+ Hyperreals *R: Introducción a la “Evaluación Perezosa” - Evaluación perezosa en python - Parte 1
+Python Hispano 21 03 2021
+Introducción a la Evaluación Perezosa
+Podemos definir “Evaluación Perezosa” como aquella evaluación que realiza los +mínimos cálculos imprecindibles para obtener el resultado final.
+La evaluación perezosa es una de las característica del languaje haskell, aunque +vamos a ver que también se puede hacer en otros lenguajes como python.
+Por ejemplo, imaginemos que queremos obtener todos los número cuadrados menores +de 100:
+cuadrados = [x**2 for x in range(1, 100)]
+resultado = [y for y in cuadrados if y < 100]
+Para obtener el resultado, antes hemos calculado la lista completa
+cuadrados, a pesar de que sólo necesitábamos unos 10 elementos.
Una posible mejora sería usar una expresión generadora:
+cuadrados = (x**2 for x in range(1, 100))
+resultado = [y for y in cuadrados if y < 100]
+Aquí los elementos de la lista cuadrados se calculan a medida que son
+necesarios, sin gastar memoria para almacenar la secuencia a medida que se
+obtiene, algo que pasaba con el ejemplo anterior. Aún así, se vuelven a calcular
+los 100 cuadrados, ya que no se corta la iteración en ningún momento.
+Necesitamos un modo de limitarnos únicamente a los elementos que vamos a utilizar.
Para quedarnos sólo con los primeros elementos vamos a usar la función
+itertools.takewhile:
from itertools import takewhile
+
+cuadrados = (x**2 for x in range(1, 100))
+resultado = list(takewhile(lambda y: y<100, cuadrados))
+En este caso, obtenemos únicamente los cuadrados necesarios, lo que supone un +importante ahorro de tiempo de cálculo.
+Si no se tiene cuidado, es muy fácil hacer más cálculos de la cuenta, e incluso +acabar en bucles infinitos o agotando los recursos de la máquina. Como veremos +en esta serie de artículos, en python se puede tener evaluación perezosa usando +correctamente iteradores y generadores.
+Tipo Range
+Veamos el siguiente código:
+>>> r = range(2,100,3)
+>>> r[10]
+32
+Normalmente, se usa la función range para crear bucles sin tener en cuenta que
+realmente es un constructor de objetos de tipo Range. Estos objetos responden
+a los mismos métodos que una lista, permitiendo obtener un elemento de cualquier
+posición de la secuencia sin necesidad de generar la secuencia completa. También
+se pueden hacer otras operaciones habituales con listas:
>>> len(r) # obtener el tamaño
+33
+>>> r[20:30] # obtener un rango
+range(62, 92, 3)
+>>> r[30:20:-1] # obtener un rango inverso
+range(92, 62, -3)
+>>> r[::-1] # la misma secuencia invertida
+range(98, -1, -3)
+>>> r[20:30:-1] # umm, secuencia vacía???
+range(62, 92, -3)
+>>> r[::2] # una nueva secuencia con distinto paso
+range(2, 101, 6)
+>>> 3 in r # comprobar si contiene un elemento
+False
+>>> r.index(65) # buscar la posición de un elemento
+21
+Como vemos, de algún modo calcula los nuevos rangos y los pasos según +necesitemos. Es suficientemente inteligente para cambiar el elemento final por +otro que considere más apropiado.
+Digamos que un objeto de tipo Range conoce cómo operar con secuencias
+aritméticas, pudiendo obtener un elemento cualquiera de la secuencia sin tener
+que calcular el resto.
Secuencias con elemento genérico conocido
+Probemos a crear algo similar a Range para la secuencia de cuadrados. Derivará
+de la clase abstracta Sequence, por lo que tenemos que definir, por lo menos,
+los métodos __len__ y _getitem__. Nos apoyaremos en un objeto range para
+esta labor (patrón Delegate):
from collections.abc import Sequence
+from typing import Union
+
+
+class SquaresRange(Sequence):
+ def __init__(self, start=0, stop=None, step=1) -> None:
+ if stop is None:
+ start, stop = 0, start
+ self._range = range(start, stop, step)
+
+ @staticmethod
+ def from_range(rng: range) -> "SquaresRange":
+ """
+ Constructor de SquaresRange a partir de un rango
+ """
+ instance = SquaresRange()
+ instance._range = rng
+ return instance
+
+ def __len__(self) -> int:
+ return len(self._range)
+
+ def __getitem__(self, idx: Union[int, slice]) -> Union[int, "SquaresRange"]:
+ i = self._range[idx]
+ return i ** 2 if isinstance(i, int) else SquaresRange.from_range(i)
+
+ def __repr__(self) -> str:
+ r = self._range
+ return f"SquaresRange({r.start}, {r.stop}, {r.step})"
+Podemos probar su funcionamiento:
+>>> for i in SquaresRange(-10, 1, 3):
+... print(i)
+...
+100
+49
+16
+1
+>>> list(SquaresRange(-1, 50, 4)[:30:2])
+[1, 49, 225, 529, 961, 1521, 2209]
+>>> SquaresRange(100)[::-1]
+SquaresRange(99, -1, -1)
+>>> 16 in SquaresRange(-10, 1, 3)
+True
+Hay que tener en cuenta que, a diferencia de un iterador, este rango no se +“agota” por lo que se puede usar repetidas veces sin ningún problema.
+Siguiendo más allá, podemos generalizar esta secuencia para se usar cualquier +función. Creamos la siguiente clase abstracta:
+from abc import abstractmethod
+from collections.abc import Sequence
+from typing import Type, Union
+
+
+class GenericRange(Sequence):
+ def __init__(self, start=0, stop=None, step=1) -> None:
+ if stop is None:
+ start, stop = 0, start
+ self._range = range(start, stop, step)
+
+ @abstractmethod
+ def getitem(self, pos: int) -> int:
+ """
+ Método abstracto.
+ Función para calcular un elemento a partir de la posición
+ """
+ return pos
+
+ @classmethod
+ def from_range(cls: Type["GenericRange"], rng: range) -> "GenericRange":
+ """
+ Constructor de un GenericRange a partir de un rango
+ """
+ instance = cls()
+ instance._range = rng
+ return instance
+
+ def __len__(self) -> int:
+ return len(self._range)
+
+ def __getitem__(self, idx: Union[int, slice]) -> Union[int, "GenericRange"]:
+ i = self._range[idx]
+ return self.getitem(i) if isinstance(i, int) else self.from_range(i)
+
+ def __repr__(self) -> str:
+ classname = self.__class__.__name__
+ r = self._range
+ return f"{classname}({r.start}, {r.stop}, {r.step})"
+Con esta clase abstracta creamos dos clases concretas, definiendo el método
+abstracto .getitem() con la función genérica:
class SquaresRange(GenericRange):
+ def getitem(self, i):
+ return i ** 2
+
+class CubicsRange(GenericRange):
+ def getitem(self, i):
+ return i ** 3
+Que podemos emplear de este modo:
+>>> for i in SquaresRange(-10, 1, 3):
+... print(i)
+...
+100
+49
+16
+1
+>>> for i in CubicsRange(-10, 1, 3):
+... print(i)
+...
+-1000
+-343
+-64
+-1
+>>> list(CubicsRange(-1, 50, 4)[:30:2])
+[-1, 343, 3375, 12167, 29791, 59319, 103823]
+>>> SquaresRange(100)[::-1]
+SquaresRange(99, -1, -1)
+>>> SquaresRange(100).index(81)
+9
+Resumen
+La Evaluación Perezosa realiza únicamente aquellos cálculos que son necesarios +para obtener el resultado final, evitando así malgastar tiempo y recursos en +resultados intermedios que no se van a usar.
+El tipo Range es algo más que una facilidad para realizar iteraciones. A +partir de un objeto range se pueden crear nuevos rangos sin necesidad de +generar ningún elementos de la secuencia.
+Si conocemos el modo de obtener cualquier elemento de una secuencia a partir de +su posición, entonces podemos crear secuencias para operar con ellas igual que +haríamos con un rango, sin necesidad de generar sus elementos.
+En el próximo artículo veremos cómo podemos ir más lejos para crear y trabajar +con secuencias infinitas de elementos.
++
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
+
+
+
+ HTML sobre WebSockets, una nueva esperanza
+República Web 21 03 2021
+En este episodio partimos del interesante artículo de Matt E. Patterson llamado «The Future of Web Software Is HTML-over-WebSockets» En el artículo se explica con detalle la evolución de la arquitectura de las aplicaciones web y la aparición de un nuevo enfoque basado en usar WebSockets. Según el autor «este nuevo enfoque basado en WebSockets está llamando la atención de los desarrolladores web. Es un enfoque que reafirma las promesas de los frameworks clásicos de server-rendering (creación rápida de prototipos, gestión del estado del lado servidor, sólido rendimiento de renderizado) y que permite la colaboración multiusuario y los diseños reactivos, sin tener que construir dos aplicaciones separadas».
+ + + +Este nuevo enfoque de HTML sobre WebSockets es complicado de asimilar cuando venimos de un arquitectura que separa claramente el lado cliente y servidor. Una gran preocupación de muchos desarrolladores es evitar soluciones complejas de lado cliente, evitando esos cientos de KB que se acumulan en el navegador. La solución es sustituir JSON por HTML, en un ciclo donde el encargado de renderizar sea siempre el servidor y envíe de forma inmediata por WebSockets el nuevo HTML a mostrar.
+ + + + + + + +Este episodio surge principalmente de un artículo de Andros Fenollosa acompañado de vídeo, donde explica este concepto de WebSockets. Aquí hablamos sobre la información compartida con Andros sobre HTML sobre WebSockets y al mismo tiempo exploramos ventajas, inconvenientes, conceptos de seguridad y frameworks. También vemos la demo creada por Andros en Django para ver el ejemplo de funcionamiento en un blog de 100 entradas.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Free Software Awards winners announced: CiviCRM, Bradley Kuhn, and Alyssa Rosenzweig
+FSF News 20 03 2021
+
+
+ Cómo usar Pam_Tally2 para gestionar los intentos fallidos de acceso en SSH
+ochobitshacenunbyte 18 03 2021
+Recientemente he tenido que gestionar en un cliente el bloqueo de ciertos usuarios, cuando querían acceder a diferentes servidores de un entorno vía SSH. Esto era debido a que, seguramente, habían puesto de forma...
+La entrada Cómo usar Pam_Tally2 para gestionar los intentos fallidos de acceso en SSH se publicó primero en ochobitshacenunbyte.
+ +
+
+ Season of Docs announces the successful 2020 long-running projects
+Google Open Source Blog 18 03 2021
+
+
+ Keyword argument functions now also accept maps
+Clojure News 18 03 2021
+
+
+To date, Clojure’s support for keyword arguments forces programmers to choose between creating APIs that better support people (accepting keyword args) or APIs that better support programs (by taking a map of those args).
+
+
+Introduced in Clojure 1.11, a function specified to take keyword arguments may be passed a single map instead of or in addition to (and following) the key/value pairs. When a lone map is passed, it is used outright for destructuring, else a trailing map is added to the map built from the preceding key/values via conj. For example, a function that takes a sequence of optional keyword arguments and returns a vector containing the values is defined as:
+
+
+
+(defn destr [& {:keys [a b] :as opts}]
+ [a b opts])
+
+(destr :a 1)
+->[1 nil {:a 1}]
+
+(destr {:a 1 :b 2})
+->[1 2 {:a 1 :b 2}]
+
+In Clojure 1.11 the call to destr accepts a mixture of key/value pairs and/or a lone (or trailing) map benefitting both programmer and program.
+
+
+ This enhancement is available now in org.clojure/clojure "1.11.0-alpha1".
+
+ Ready for QA
+MonkeyUser 18 03 2021
+
+
+
+
+ LIDERAZGO Y LA MAYÉUTICA DE SÓCRATES
+Diario Estoico 17 03 2021
+
+
+
+
+ Content Management Made Simple
+The History of the Web 16 03 2021
+Content Management Systems — software that helps people author and publish websites — likely dates back farther than you think. The problem is, it wasn't quite called that yet.
+The post Content Management Made Simple appeared first on The History of the Web.
+ +
+
+ Errores convertidos en calidad de producto con Firebase Crashlytics
+En Mi Local Funciona 16 03 2021
+
+ 
+
+
+ Trolley Conundrum
+MonkeyUser 16 03 2021
+
+
+ Hyperreals *R: Formalización de la Secuencia Perezosa - Evaluación perezosa en python - Parte 5
+Python Hispano 15 03 2021
+Refactorización
+Hasta ahora hemos visto cómo crear una secuencia perezosa que va guardando en +una caché los resultados de una operación (proceso de memoización). Así mismo, +cuando la secuencia es una secuencia ordenada podemos optimizar algunas +búsquedas, tal como vimos con la secuencia de números primos.
+Vamos a intentar darle una forma a todo esto creando las clases LazySequence y
+LazySortedSequence.
El código refactorizado final se puede descargar a continuación:
+ +LazySequence
+La clase LazySequence crea una secuencia perezosa a partir de un iterador.
+A medida que obtenga elementos del iterador, los va almacenando en una caché:
T = TypeVar("T", covariant=True)
+
+class LazySequence(Iterator[T]):
+ def __init__(self, iterator: Iterator[T]):
+ self._cache: list[T] = []
+ self.iterator = iterator
+
+ def __next__(self) -> T:
+ x = next(self.iterator)
+ self._cache.append(x)
+ return x
+Cada vez que se calcule un nuevo elemento a través de next(), éste se añadirá
+a la caché.
Para que funcione como secuencia, se implementan los métodos __getitem__:
@singledispatchmethod
+ def __getitem__(self, idx):
+ return NotImplemented
+
+ @__getitem__.register
+ def __getitem_int__(self, idx: int) -> T:
+ if idx < 0:
+ raise OverflowError
+ elif idx >= self.size:
+ self._cache.extend(islice(self.iterator, idx - self.size + 1))
+
+ return self._cache[idx]
+
+ @__getitem__.register
+ def __getitem_slice__(self, sl: slice) -> list[T]:
+ rng = range(INFINITE)[sl]
+ return [self[i] for i in rng]
+Y añadimos el método __iter__ para cumplir con el protocolo iterator:
def __iter__(self) -> Iterator[T]:
+ yield from self._cache
+ yield from (self[i] for i in range(len(self._cache), INFINITE))
+LazySortedSequence
+Derivando de LazySequence, se crea la clase LazySortedSequence para cuando
+el iterador produzca una secuencia ordenada. Tal como hemos visto, cuando la
+secuencia está ordenada podemos realizar búsquedas por bisecciones que
+resultan bastante eficiente.
La operación principal será el método insertpos() que nos indica la posición
+en la que se insertaría un elemento en la secuencia, manteniendo el orden de los
+elementos. Si no son suficientes con los elementos de la caché, se extraerán más
+del iterador mediante next(), que irán añadiéndose progresivamente a la caché:
Ord = TypeVar("Ord", bound=int, covariant=True)
+
+class LazySortedSequence(LazySequence[Ord]):
+ def insertpos(self, x: int) -> int:
+ if self.size > 0 and x <= self.last:
+ idx = bisect_left(self._cache, x)
+ else:
+ while x > next(self):
+ pass
+ idx = self.size - 1
+
+ return idx
+Con el método insertpos() ya podemos definir los métodos __contains__() e
+index() típicos de la secuencias:
def __contains__(self, x: int) -> bool:
+ idx = self.insertpos(x)
+ return x == self._cache[idx]
+
+ def index(self, x: int) -> int:
+ idx = self.insertpos(x)
+ if x == self._cache[idx]:
+ return idx
+ raise ValueError(f"{x} is not in {self.__class__.__name__}")
+No existe un protocolo para elementos ordenables (Sortable, Ordered). Para
+ordenar elementos se usan los métodos de comparación __eq__, __ne__,
+__lt__, __le__, __gt__ y __ge__. Pero se suele considerar estos métodos
+redundantes ya que basta con definir sólo dos (eg: __eq__ y __lt__) para
+establecer una ordenación.
Como no hay una forma mejor, hemos creado el tipo genérico Ord enlazado con
+int para que al menos el chequeador de tipos no se queje en la comparaciónes,
+aunque no tiene porqué limitarse su aplicación a números enteros.
Números primos
+Como caso práctico, veamos cómo se puede redefinir la clase Primes:
@final
+class Primes(LazySortedSequence[Prime]):
+ def __init__(self):
+ super().__init__(self.__genprimes())
+ self._cache.extend([2, 3])
+
+ def __genprimes(self) -> Iterator[Prime]:
+ _primes = self._cache
+ start = 5
+ top = 1
+ while True:
+ stop = _primes[top] ** 2
+ for n in range(start, stop, 2):
+ for p in islice(_primes, 1, top):
+ if n % p == 0:
+ break
+ else:
+ yield n
+
+ start = stop + 2
+ top += 1
+Si dejamos así la codificación, la clase Primes usará el método __contains__
+de LazySortedSequence. Este método añadirá primos a la caché hasta alcanzar el
+argumento solicitado.
Si recordamos de la implementación anterior que teníamos de la clase Primes,
+el método __contains__() estaba optimizado para comprobar la pertencia de un
+número, sin añadir más elementos a la caché. Vamos a recuperar esta codificación:
def __contains__(self, n: int) -> bool:
+
+ if n <= self.last:
+ return super().__contains__(n)
+
+ root = isqrt(n)
+ _primes = self._cache
+
+ top = self.size if root > self.last else self.insertpos(root)
+
+ if any(n % prime == 0 for prime in islice(_primes, 1, top)):
+ return False
+
+ # "one-shot" check
+ if any(n % i == 0 for i in range(self.last + 2, root + 1, 2)):
+ return False
+
+ return True
++
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
+
+ Hyperreals *R: Evaluación perezosa en python - Apéndice
+Python Hispano 15 03 2021
+Apéndice: sobre el tipado de datos utilizado
+Durante esta serie de artículos he procurado usar el tipado gradual de python, +no sólo para mejorar la compresión, sino porque lo considero buena práctica para +detectar algunos problemas en el momento de escribir el código. El intérprete de +python realmente no realiza ningún chequeo de estas anotaciones de tipos, +dejando por completo su comprobación a alguna otra herramienta que pueda estar +usando el desarrollador.
+He utilizado las clases abstractas del módulo collections.abc como base para
+definir los iterables, secuencias e iteradores. He creído que así quedaba
+mejor documentado, además de ser el modo más conocido por programadores de otros
+lenguajes. Por derivar de la clase abstracta Sequence, sabemos que
+GenericRange implementa varios métodos abstractos como son __len__ y
+__getitem__.
Sin embargo, en python se considera supérfluo y poco recomendable este uso de +clases abstractas. El modo pythónico consiste en implementar esos métodos sin +más indicación. Sólo por el hecho de contar con estos métodos, nuestra clase ya +será considerada como secuencia, se podrá usar donde haga falta una +secuencia y, en definitiva, se comportará como si fuera una secuencia. Son los +llamados duck types o tipos estructurales que tanto caracterizan a python y +que, a partir de ahora, nos vamos a tener que acostumbrar a denominar +Protocolos.
+Por ejemplo, podíamos haber declarado la clase GenericRange sin indicar
+ninguna superclase:
class GenericRange:
+ def __init__(self, start=0, stop=None, step=1) -> None:
+ ...
+
+ def __len__(self) -> int:
+ ...
+
+ def __getitem__(self, idx: Union[int, slice]) -> Union[int, "GenericRange"]:
+ ...
+Al tener el método __len__() se dice que cumple con el protocolo Sized,
+algo que se puede comprobar del mismo modo que si fuera una subclase:
>>> from collections.abc import Sized
+>>> issubclass(GenericRange, Sized)
+True
+En cambio, nos puede sorprender que no cumpla con el protocolo Sequence, a
+pesar de que se comportaba como tal:
>>> from collections.abc import Sequence
+>>> issubclass(GenericRange, Sequence)
+False
+Resulta que para cumplir con el protocolo Sequence, además de __getitem__(),
+debe tener implementados los métodos __iter__(), __reversed__() e
+index().
Cuando GenericRange derivaba de Sequence, estos métodos se heredaban de la
+superclase como métodos mixin, para cuya implementación básica utiliza
+únicamente el método __getitem__(). También implementa otros métodos como
+__contains__() (Container) y count() (Countable). Ése era el motivo por
+el que sólo hacía falta definir __getitem__() para que funcionara como secuencia.
Como protocolo, estos métodos no se adquieren por herencia y necesitan una implementación para cumplir con el protocolo Sequence. No obstante, algunas funciones, como reversed, admiten objetos con implementaciones parciales del protocolo Sequence, algo que únicamente sabremos si recurrimos a la documentación de la función.
Secuencia de enteros
+He empleado el tipo Sequence sin indicar de qué tipo son los elementos. Un
+chequeador de tipos asume que se trata de un iterable de elementos de tipo
+Any, por lo que no debería dar problemas. Pero siempre podemos ser más
+precisos y usar Sequence[int] como tipo de datos para nuestras secuencias de
+números enteros.
Referencia forward
+En la anotaciones de tipos, a veces necesitamos referenciar una clase antes de +que esté definida, las conocidas como referencias forward de tipos. El modo +normal de hacer este tipo de referencias es escribir el nombre de la clase entre +comillas, como una string.
+A partir de python 3.10 no hará falta acudir a este remedio pudiendo usar
+referencias forward sin mayor problema. Para las versiones anteriores, se
+puede obtener esta funcionalidad del módulo __future__:
from __future__ import annotations
+Unión de tipos
+En el método __getitem__() de GenericRange he utilizado dos uniones de tipos:
def __getitem__(self, idx: Union[int, slice]) -> Union[int, "GenericRange"]:
+ i = self._range[idx]
+ return self.getitem(i) if isinstance(i, int) else self.from_range(i)
+La unión idx: Union[int, slice] se puede interpretar como que idx puede ser
+de tipo int o de tipo slice. La notación común de expresar esta unión de
+tipos en varios lenguajes sería idx: int | slice, nomenclatura que también
+será aceptada en python 3.10.
La otra unión, Union[int, "GenericRange"] indica que el resultado será de tipo
+int o de tipo GenericRange.
De todos modos, en estas anotaciones no se está reflejando la dependencia que
+hay entre tipos. Si idx es entero, el resultado siempre será un entero. Si
+idx es slice, el resultado siempre será GenericRange. En lenguajes con
+tipado estático, es normal disponer de varias definiciones del mismo métodos,
+con diferentes signaturas, que se seleccionan según sean los tipos de los
+argumentos y resultados que tengamos.
Python tiene una facilidad para hacer algo similar. Con
+functools.singledispathmethod podemos definir varios métodos que se invocarán
+según el tipo de dato del primer argumento. De este modo, el método
+__getitem__() lo podríamos expresar así:
from functools import singledispatchmethod
+
+class GenericRange(Sequence):
+ ...
+
+ @singledispatchmethod
+ def __getitem__(self, idx):
+ return NotImplemented
+
+ @__getitem__.register
+ def _(self, idx: int) -> int:
+ i = self._range[idx]
+ return self.getitem(i)
+
+ @__getitem__.register
+ def _(self, idx: slice) -> "GenericRange":
+ i = self._range[idx]
+ return self.from_range(i)
+Lamentablemente nos saldrá un error ya que no existe aún la clase GenericRange
+cuando es aplicado el decorador singledispatchmethod. Una solución es sacar el
+último registro fuera, una vez que ya se ha definido la clase:
@GenericRange.__getitem__.register
+def _(self, idx: slice) -> GenericRange:
+ i = self._range[idx]
+ return self.from_range(i)
+Código final
+Con estos cambios, tendríamos nuestro código corregido de esta manera:
+from abc import abstractmethod
+from collections.abc import Sequence
+from typing import Type, Union
+from functools import singledispatchmethod
+from __future__ import annotations
+
+class GenericRange(Sequence[int]):
+ def __init__(self, start=0, stop=None, step=1) -> None:
+ if stop is None:
+ start, stop = 0, start
+ self._range = range(start, stop, step)
+
+ @abstractmethod
+ def getitem(self, pos: int) -> int:
+ """
+ Método abstracto.
+ Función para calcular un elemento a partir de la posición
+ """
+ return pos
+
+ @classmethod
+ def from_range(cls: Type[GenericRange], rng: range) -> GenericRange:
+ """
+ Constructor de un GenericRange a partir de un rango
+ """
+ instance = cls()
+ instance._range = rng
+ return instance
+
+ def __len__(self) -> int:
+ return len(self._range)
+
+ @singledispatchmethod
+ def __getitem__(self, idx):
+ return NotImplemented
+
+ @__getitem__.register
+ def _(self, idx: int) -> int:
+ i = self._range[idx]
+ return self.getitem(i)
+
+ def __repr__(self) -> str:
+ classname = self.__class__.__name__
+ r = self._range
+ return f"{classname}({r.start}, {r.stop}, {r.step})"
+
+
+@GenericRange.__getitem__.register
+def _(self, idx: slice) -> GenericRange:
+ i = self._range[idx]
+ return self.from_range(i)
+Conclusión
+Python está realizando un gran esfuerzo en incorporar anotaciones de tipo sin +perder con ello sus característicos tipos ducking. De igual modo, vamos a ver +cómo se incorporan más elementos de otros lenguajes como las dataclasses, +programación asíncrona o los patrones estructurales, aunque tardarán en ser +adoptados por la mayor parte de programadores python.
+Si algo tiene python es no tener demasiada prisa en que se apliquen sus cambios. +Como decía un gran sabio: “Vamos a cambiarlo todo para que todo siga igual”.
++
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
+
+ Hyperreals *R: Evaluación perezosa avanzada - Evaluación perezosa en python - Parte 4
+Python Hispano 15 03 2021
+Evaluación perezosa avanzada
+Haskell tiene una librería, Data.Numbers.Primes, que ofrece tanto una
+secuencia con todos los números primos, primes, como la función isprime con
+la que chequear si un número es primo. Gracias a la evaluación perezosa,
+haskell sólo calcula los elementos de primes que necesite.
Vamos a intentar hacer en python lo que hace sencillo haskell:
+> take 100 primes
+[2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97,101,103,
+107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,
+223,227,229,233,239,241,251,257,263,269,271,277,281,283,293,307,311,313,317,331,
+337,347,349,353,359,367,373,379,383,389,397,401,409,419,421,431,433,439,443,449,
+457,461,463,467,479,487,491,499,503,509,521,523,541]
+
+> primes!!90000
+1159531
+
+> isPrime (2^31-1)
+True
+Calculo de números primos
+Por definición, un número primo sólo es divisible por 1 y por sí mismo:
Prime = int # un alias para números primos
+
+def isprime(n: int) -> bool:
+ return not any(n % i == 0 for i in range(2, n))
+
+def primes(to: int) -> list[Prime]:
+ return [i for i in range(2, to+1) if isprime(i)]
+Podemos aplicar algunas optimizaciones a estos cálculos:
+-
+
- Excepto el 2, podemos descartar como primos todos los números pares +
- Al comprobar divisores de \(n\), basta con probar hasta \(\sqrt{n}\), y únicamente + con aquellos que sean primos +
Con estas premisas, podemos ir ya diseñando una estrategia para obtener una +secuencia de primos por evaluación perezosa:
+import sys
+from collections.abc import Generator, Iterable
+from itertools import islice
+
+INFINITE = sys.maxsize # una aproximación 'mala' para infinito
+Prime = int # un alias para números primos
+
+# lista de números primos que vayamos obteniendo
+primes: list[Prime] = [2, 3]
+
+
+def isdivisible(n: int, divisors: Iterable[int]) -> bool:
+ """
+ Comprobar si 'n' es divisible por
+ los elementos de un iterable ordenado
+ """
+
+ divisible = False
+ for d in divisors:
+ if n % d == 0:
+ divisible = True
+ break
+ if d * d > n:
+ break
+ return divisible
+
+
+def isprime(n: int) -> bool:
+ """Comprobar si 'n' es un número primo"""
+
+ if n <= primes[-1]:
+ return n in primes
+
+ # probando primos como divisores
+ if isdivisible(n, primes):
+ return False
+
+ # seguir con el resto de números impares
+ start = primes[-1] + 2
+ return not isdivisible(n, range(start, n, 2))
+
+
+def genprimes() -> Generator[Prime, None, None]:
+ """Generador de números primos"""
+
+ start = primes[-1] + 2
+ for n in range(start, INFINITE, 2):
+ if not isdivisible(n, primes):
+ primes.append(n)
+ yield n
+El generador genprimes nos dará un iterador con el que ir obteniendo los
+números primos siguientes al último de la lista. A medida que obtiene un primo,
+se añade a la lista primes.
La lista primes actua como caché de los números primos obtenidos y la
+empleará isprime para sus comprobaciones. Si isprime se queda sin primos,
+continua con los siguientes números impares hasta obtener un resultado, sin
+pararse a calcular los primos intermedios.
Secuencia de números primos
+Vistas estas funciones vamos a armar con ellas la estructura de una clase
+secuencia. isprime pasará a ser el método __contains__ y el generador
+genprimes lo usaremos para ampliar automáticamente la lista de números primos
+según sea necesario:
import sys
+from collections.abc import Generator, Iterable
+from itertools import islice
+from typing import Union
+
+INFINITE = sys.maxsize # una mala aproximación de infinito
+Prime = int # un alias para los primos
+
+
+def isdivisible(n: int, divisors: Iterable[int]) -> bool:
+ """
+ Comprobar si 'n' es divisible por
+ los elementos de un iterable ordenado
+ """
+
+ divisible = False
+ for d in divisors:
+ if n % d == 0:
+ divisible = True
+ break
+ if d * d > n:
+ break
+ return divisible
+
+
+def nth(it: Iterable, n: int):
+ """Obtener de un iterable el elemento en la posición 'n'"""
+ return next(islice(it, n, None))
+
+
+class Primes:
+ """
+ Collection of primes numbers
+ """
+
+ def __init__(self):
+ self._primes: list[Prime] = [2, 3]
+
+ @property
+ def last(self) -> Prime:
+ return self._primes[-1]
+
+ @property
+ def size(self) -> int:
+ return len(self._primes)
+
+ def __len__(self) -> int:
+ return INFINITE
+
+ def __contains__(self, n: int) -> bool:
+ """Comprobar si 'n' es un número primo"""
+
+ if n <= self.last:
+ return n in self._primes
+
+ # probando primos como divisores
+ if isdivisible(n, self._primes):
+ return False
+
+ # seguir con el resto de números impares
+ start = self.last + 2
+ return not isdivisible(n, range(start, n, 2))
+
+ def genprimes(self) -> Generator[Prime, None, None]:
+ """Generador de números primos"""
+
+ start = self.last + 2
+ for n in range(start, INFINITE, 2):
+ if not isdivisible(n, self._primes):
+ self._primes.append(n)
+ yield n
+
+ def __getitem__(self, idx: Union[int, slice]) -> Prime:
+ if isinstance(idx, int):
+ if idx < 0:
+ raise OverflowError
+
+ return (
+ self._primes[idx]
+ if idx < self.size
+ else nth(self.genprimes(), idx - self.size)
+ )
+ else:
+ rng = range(INFINITE)[idx]
+ return [self[i] for i in rng]
+
+# Secuencia de los números primos
+primes = Primes()
+isprime = primes.__contains__
+Como infinito se usa sys.maxsize que es el mayor tamaño que puede tener una
+lista para la versión CPython. Si tratamos de usar índices mayores para una
+lista nos dará error.
Cuando se solicita un número primo que no está en la lista, el método
+__getitem__ invoca automáticamente al iterador que devuelve genprimes hasta
+alcanzarlo. A medida que se descubren números primos, se val almacenando para su
+posterior uso.
Pruebas de uso:
+>>> from primes import primes, isprime
+>>> print(primes[:100])
+[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73,
+ 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157,
+ 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241,
+ 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347,
+ 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439,
+ 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541]
+>>> primes[90000]
+1159531
+>>> isprime(2**31-1)
+True
+>>> (2**31-1) in primes._primes
+False
+>>> primes.last
+1159531
+Para cumplir con el protocolo Sequence podemos añadir los métodos que nos
+faltan, cosa que animo hacer al lector. El método count() es trivial: si es
+primo, habrá 1 ocurrencia; si no es primo, 0 ocurrencias. El método index() es
+algo más complicado. En cambio el _reversed__() es imposible ya que no se
+puede invertir una secuencia infinta. A pesar de ello, la clase Prime se
+comportará casi como una secuencia siempre y cuando no itentemos acceder a la
+secuencia por el final.
Más optimizaciones
+Bisecciones
+La lista de primos que vamos generando siempre será una lista ordenada, por lo
+que se pueden optimizar mucho las búsquedas usando bisecciones, para lo que
+tenemos el módulo bisect (\(O(\log{n})\) en lugar de \(O(n)\)).
Por ejemplo, para comprobar si un elemento está en una lista ordenada:
+from bisect import bisect_left
+
+def bs_contains(lst: list, x) -> bool:
+ idx = bisect_left(lst, x)
+ return idx < len(lst) and lst[idx] == x
+Programación dinámica
+En el generador de números primos podemos observar que se están comprobando los
+cuadrados de los divisores más veces de las necesarias. Podemos delimitar rangos
+en los que se van a usar los mismos divisores. Por ejemplo, si tenemos la
+secuencia [2, 3] como divisores podemos chequear números hasta el 23. Para
+seguir con el 25 tenemos que añadir un primo más, [2, 3, 5] con los que ya
+podemos chequear hasta el 47. Y así sucesivamente. El rango range(start,
+INFINITE, 2) lo podemos fraccionar según el grupo de primos que emplearemos
+como divisores.
La programación dinámica tiene sus riesgos y es bastante fácil que no funcione +bien a la primera, pero mejoran mucho la eficiencia de un algoritmo.
+Multiproceso
+Como opción de mejora está el uso de técnicas de concurrencia y multiproceso. +Como primera medida que podemos pensar sería crear varios workers que chequeen +en paralelo la divisibilidad para chequear varios números a la vez. El problema +es que estos workers tendrían que tener su copia de la lista de primos y +actualizarla conforme se obtenien, algo que es sumamente costoso y poco eficiente.
+Una estrategia mejor sería especializar cada worker en un subconjunto de +números primos de modo que todos los workers intervengan colaborativamente en +el chequeo del mismo número.
+En concurrencia, hay muchas estrategias posibles y ninguna mejor. Al final, cada +problema tiene su solución particular que no sirve como solución general.
+Código final optimizado
+El código final optimizado, sin usar concurrencia, se puede obtener del +siguiente enlace:
+
+
+Descarga
+ +Por hacernos una idea, esta sería la comparativa de tiempos de la versiones haskell y python:
+ + + + +| operación | +haskell | +python | +python opt | +
|---|---|---|---|
| primo 90000 | +310ms | +1450ms | +860ms | +
| es primo \(2^{31}-1\) | +20ms | +10ms | +3ms | +
| index 1159531 | +240ms | +N/A | +820ms | +
+
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
+
+ Hyperreals *R: Memoización - Evaluación perezosa en python - Parte 3
+Python Hispano 15 03 2021
+Cachés y Memoización
+En el pasado artículo vimos que para obtener un elemento de la sucesión +fibonacci necesitábamos calcular los anteriores. Veámoslo con más detalle.
+Podemos definir la siguiente función para obtener un elemento de esta sucesión:
+def fib(n):
+ if n < 2:
+ return n
+ return fib(n-1) + fib(n-2)
+Esta función tiene un terrible problema de eficacia, puesto que se llama a sí
+misma demasiadas veces para calcular el mismo elemento. Por ejemplo, para
+calcular fib(10) llama una vez a fib(9) y a fib(8), pero para calcular
+fib(9) también llama a fib(8). Si sumamos todas las llamadas, habrá
+necesitado llamar:
-
+
fib(9)1 vez
+fib(8)2 veces
+fib(7)3 veces
+fib(6)5 veces
+fib(5)8 veces
+fib(4)13 veces
+fib(3)21 veces
+fib(2)34 veces
+fib(1)55 veces
+fib(0)34 veces
+
Para elementos mayores, todavía serán más las llamadas que se habrán repetido.
+Un mejora nos la da la propia documentación de python como aplicación de la
+función functools.lru_cache:
from functools import lru_cache
+
+@lru_cache(maxsize=None)
+def fib(n):
+ if n < 2:
+ return n
+ return fib(n-1) + fib(n-2)
+Básicamente, lru_cache es un decorador que detecta los argumentos que se
+pasa a una función y guarda en un caché el resultado que devuelve. Un caché
+LRU (Least Recently Used ) tiene la estrategia de eliminar de la caché los
+elementos que hayan sido menos utilizados recientemente. En este caso, con
+maxsize=None no se impone ningún límite de tamaño, por lo que guardará todos
+los elementos de la caché 1.
A este proceso de guardar los resultados de una evaluación en función de los +argumentos de entrada se conoce por “memoize” o “memoización”, y es +fundamental para la evaluación perezosa.
+Podemos obtener información de la caché:
+>>> fib(10)
+>>> fib.cache_info()
+CacheInfo(hits=8, misses=11, maxsize=None, currsize=11)
+Nos dice que la caché tiene 11 elementos (la serie de fib(0) a fib(10)), que
+ha fallado 11 veces, una por elemento de la sucesión, pero sí que ha acertado 8.
+Una importante mejora de como lo teníamos antes.
Aún así, en python tenemos limitado el número de llamadas recursivas que se +pueden hacer, que suele estar en torno a unas 3000 llamadas recursivas 2:
+>>> fib(10000)
+...
+RecursionError: maximum recursion depth exceeded in comparison
+Para no tener este problema, en la documentación hacen el truco de ir visitando +en orden todos los elementos de la sucesión hasta llegar al que queremos.
+>>> [fib(n) for n in range(16)]
+[0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610]
+Con este truco se instruye a la caché con todos los elementos de la sucesión +hasta llegar al que queremos. Para el cálculo de un elemento sólo se necesitarán +los dos elementos anteriores de la sucesión, que ya tendremos en la caché, lo +que evita múltiples llamadas recursivas.
+Con este mismo propósito, podemos probar a calcular el elemento 10000 aplicando +las técnicas ya aprendidas hasta ahora:
+from itertools import count, islice
+from functools import lru_cache
+
+ℕ = count(0)
+suc_fib = (fib(n) for n in ℕ)
+fib10k = next(islice(suc_fib, 10000, None))
+Esta gestión de la caché es totalmente opaca para nosotros. Si pudiéramos +acceder a ella sería un modo de obtener la sucesión de fibonacci hasta el mayor +elemento que se haya calculado.
+Vamos a itentar crear una caché similar capaz de generar automáticamente los +elementos de la sucesión:
+def fibcache(f):
+ cache = []
+ def wrap(n):
+ for i in range(len(cache), n + 1):
+ cache.append(f(i))
+ return cache[n]
+
+ wrap.cache = cache
+
+ return wrap
+
+@fibcache
+def fib(n):
+ if n < 2:
+ return n
+ return fib(n-1) + fib(n-2)
+Hemos creado el decorador, fibcache que añade una caché a la función que
+decora. Al hacer la llamada fib(n), este decorador se asegura que todos los
+elementos anteriores de la sucesión estén en la caché. La caché es accesible
+mediante el atributo fib.cache, que no será otra cosa que la sucesión de fibonacci.
>>> fib(10000)
+3364476487643178326662161200510754331030214846068006390656476997468008144216....
+...
+>>> fib.cache[10000]
+3364476487643178326662161200510754331030214846068006390656476997468008144216....
+...
+Lo genial de esta estrategia es que sólo calculamos los mínimos elementos +necesarios para obtener el resultado buscado, algo que es el fundamento de lo +que conocemos por evaluación perezosa.
+Resumen
+Aplicando técnicas de memoización, hemos conseguido que una función recursiva +almacene los cálculos que hace para así evitar repetirlos, con lo que es posible +reducir los niveles de recursividad.
+Con un decorador, hemos asociado una caché a una función que se rellena +automáticamente, y en orden, con los resultados intermedios hasta llegar al +resultado solicitado. Esta caché será una sucesión ordenada de resultados, que +crece a medida que se necesite.
+A este proceso de realizar cálculos según sea necesario es lo que conocemos por +Evaluación Perezosa.
++
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
ANOTACIONES:
+
+
+
+ +
-
+
-
+
Existe un decorador equivalente,
+functools.cache, que también sirve para +crear cachés sin límite, pero no contabiliza el número de aciertos. ↩
+ -
+
El límite de llamadas recursivas se obtiene con la función +
+sys.getrecursionlimit()y se podría alterar consys.setrecursionlimit, +aunque no es recomendable. ↩
+
+
+ Hyperreals *R: Secuencias infinitas - Evaluación perezosa en python - Parte 2
+Python Hispano 15 03 2021
+Algunas definiciones
+Puede ser interesante dejar claras algunas definiciones para distinguir entre +iteradores e iterables (se pueden ver las definiciones completas en el +glosario de python):
+-
+
- Iterable +
- cualquier objeto capaz de devolver sus miembros de uno en uno +
- Iterador +
- iterable que representa un flujo de datos, cuyos elementos se +
- obtienen uno detrás de otro +
- Secuencia +
- iterable con acceso eficiente a sus elementos mediante un índice entero +
- Generador +
- función que devuelve un iterador +
- Expresión generadora +
- expresión que devuelve un iterador +
Lo importante a tener en cuenta es que tenemos dos grandes grupos de +iterables: los iteradores y las secuencias.
+Los elementos de una secuencia son accesibles por su posición, mientras que +los elementos de un iterador sólo se pueden acceder en serie. Iterable sería +el concepto más general que englobaría ambos términos.
+En el resto del artículo hablaremos de “secuencias” como término matemático, +aunque su implementación podría corresponder con cualquier iterable de los mencionados.
+Secuencias infinitas
+En python, para crear secuencias infinitas se suelen usar generadores. Por +ejemplo, para obtener la secuencia de Números Naturales se podría hacer así:
+from collections.abc import Iterable
+
+def ℕ() -> Iterable[int]:
+ n = 0
+ while 1:
+ yield n
+ n += 1
+No podemos tratar las secuencias infinitas del mismo modo que con una lista. +Necesitamos las funciones del módulo itertools capaces de operar con +iteradores para pasar a una lista en el momento que realmente la necesitemos. Al +final de la documentación del módulo se incluyen algunas +recetas que dan idea de lo que pueden hacer.
+Por ejemplo, podríamos redefinir la secuencia de número naturales con
+itertools.count:
from itertools import count
+
+ℕ = count(0)
+Para obtener los primeros 100 números naturales
+from itertools import islice
+
+print(list(islice(ℕ, 100)))
+
+[100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199]
+Emular la función enumerate:
from collections.abc import Iterable, Iterator
+
+def enumerate(it: Iterable) -> Iterator:
+ ℕ = count(0)
+ return zip(ℕ, it)
+¿Y si quisiéramos obtener la lista de cuadrados en el intérvalo [100, 200).
+Veamos (NO PROBAR):
ℕ = count(0)
+cuadrados = (n**2 for n in ℕ)
+res = [x for x in cuadrados if 100<=x<200]
+Si probabos es posible que se quede en un bucle infinito. Necesita comprobar +todos los elementos, por lo que se pondrá a calcular todos lo elementos de la +sucesión para ver si cumplen la condición.
+Como sabemos que la sucesión de cuadrados es creciente, podemos pararla en el +momento que se salga de límites:
+from itertools import dropwhile, takewhile
+
+ℕ = count(0)
+cuadrados = (n ** 2 for n in ℕ)
+mayores_100 = dropwhile(lambda x: x < 100, cuadrados)
+menores_200 = takewhile(lambda x: x <= 200, mayores_100)
+res = list(menores_200)
+En definitiva, hemos encadenado varias funciones hasta conseguir el iterador que +necesitábamos. En programación funcional, a este encadenado de funciones se +denomina como composición de funciones y es bastante utilizado. +Lamentablemente, en python no existe este tipo de operaciones.
+Ejemplo: sucesión de Fibonacci
+La sucesión de Fibonacci se define de la siguiente manera:
+$$f_0=1$$
+$$f_1=1$$
+$$f_n = f_{n-1} + f_{n-2}$$
+Operando, podemos obtener la sencuencia:
+1
+1
+1+1 -> 2
+1+2 -> 3
+2+3 -> 5
+...
+La lista de los 20 primeros:
+[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765]
+Un modo simple de construir la serie es usar un generador:
+from collections.abc import Iterator
+from itertools import islice
+
+def fib() -> Iterator[int]:
+ a, b = 1, 1
+ while True:
+ yield a
+ a, b = b, a+b
+
+# primeros 20 elementos
+print(list(islice(fib(), 20)))
+Para obtener un elemento en una posición dada tenemos que consumir el +iterador, elemento a elemento, hasta llegar a la posición que queremos.
+Por ejemplo, para obtener el elemento de la posición 1000:
+>>> next(islice(fib(), 1000, None))
+70330367711422815821835254877183549770181269836358732742604905087154537118196933
+57974224949456261173348775044924176599108818636326545022364710601205337412127386
+7339111198139373125598767690091902245245323403501
+Ha sido necesario calcular todos los elementos anteriores hasta llegar al que +deseamos, algo que hay que repetir para cada uno de los elementos que queramos extraer.
+Afortunadamente, la sucesión de fibonacci tiene elemento genérico que se expresa +en función de el número áureo \(\varphi\) y que tiene la siguiente formulación:
+$$\varphi ={\frac {1+{\sqrt {5}}}{2}}$$
+Usando el número áureo, un elemento de la serie fibonacci se puede calcular +con la siguiente fórmula de Édouard Lucas,:
+$$f_n=\frac{\varphi^n-\left(1-\varphi\right)^{n}}{\sqrt5}$$
+Que podemos ajustar el redondeo y expresar como:
+$$f_{n}=\operatorname {int} \left({\frac {\varphi ^{n}}{\sqrt {5}}}+{\frac {1}{2}}\right)$$
+Así pues, podemos echar mano de la secuencia GenericRange que vimos en el
+artículo anterior para definir una secuencia para fibonacci:
class FibRange(GenericRange):
+ def getitem(self, n):
+ sqrt5 = 5**(1/2)
+ φ = (1 + sqrt5) / 2
+ return int(φ**n/sqrt5 + 1/2)
+
+
+>>> list(FibRange(100,110))
+[354224848179263111168,
+ 573147844013818970112,
+ 927372692193082081280,
+ 1500520536206901248000,
+ 2427893228399983329280,
+ 3928413764606884839424,
+ 6356306993006868692992,
+ 10284720757613753532416,
+ 16641027750620622225408,
+ 26925748508234379952128]
+Lamentablemente, aunque al final se obtenga un número entero, para hacer el +cálculo hemos recurrido al cálculo numérico de coma flotante, lo que produce +desbordamiento cuando trabajamos con números grandes. Tenemos que buscar otros +métodos para mantenernos en el dominio de los número enteros. Pero lo dejaremos +ya para el próximo artículo, donde veremos las memoizaciones o el modo de +guardar los resultados de un función para evitar repetir el mismo cálculo cuando +se vuelva a necesitar.
+Resumen
+Las secuencias numéricas se pueden expresar en forma de iterables, de las que
+tenemos dos tipos: iteradores y secuencias.
Normalmente en python, para trabajar con secuencias infinitas se usan
+iteradores. Para poder manejar estos iteradores se usan las funciones del módulo
+itertools que podemos combinar para obtener como resultado un iterable que ya
+podemos manejar mejor.
Si la secuencia tiene definido un elemento genérico, entonces podemos utilizar +los rangos que ya habíamos visto anteriormente para crear la secuencia infinita.
++
Serie Evaluación Perezosa en Python
+-
+
- Parte 1 - Introducción a la evaluación perezosa +
- Parte 2 - Secuencias infinitas +
- Parte 3 - Memoización +
- Parte 4 - Evaluación perezosa avanzada +
- Parte 5 - Formalización de la Secuencia Perezosa +
- Parte 6 - Ejemplo práctico: Potencias de Fermi-Dirac +
- Apéndice: sobre el tipado de datos utilizado +
+
+La serie unificada como Jupyter Notebook en:
+ ++
+
+ Rethinking the JavaScript ternary operator
+James Sinclair 15 03 2021
+
+
+ Rethinking the JavaScript ternary operator
+Web Development - James Sinclair 15 03 2021
+
- 
+
-
Itinerario de Desarrollador Backend
-Podcast República Web 30 11 2019
+freeCodeCamp ya habla español con Rafael Hernandez
+República Web 14 03 2021
Recientemente freeCodeCamp, una de las comunidades de aprendizaje tecnológico más importantes en internet, anunció las versiones en español y en chino de sus contenidos. Este anuncio fue recibido con entusiasmo entre el público hispanohablante, ya que freeCodeCamp es un recurso imprescindible para aprender desarrollo web. Gracias a sus contenidos cada día miles de personas en todo el mundo pueden aprender de manera abierta y sin coste, habilidades relacionadas con las tecnologías de internet y conocimientos técnicos.
+ + + +Para hablar sobre esta iniciativa de freeCodeCamp, por indicación del propio fundador Quincy Larson, invitamos al podcast a Rafael Hernández, coordinador desde Los Ángeles, del equipo encargado de la comunidad hispanohablante. Con Rafael discutimos entre otras cosas:
+ + + +-
+
- El origen de freeCodeCamp y sus principales objetivos. +
- Las perspectivas con respecto al idioma español y a otros idiomas en la comunidad de freeCodeCamp. +
- Requisitos y solicitudes para participar como voluntario. +
- El trabajo de los voluntarios y su coordinación. +
- Financiación de freeCodeCamp y formas de donación. +
- Certificaciones de freeCodeCamp y valoraciones a nivel profesional. +
- Colaboraciones con empresas tecnológicas y acuerdos de colaboración. +
- Edición y gestión de contenidos. +
- Futuro y acciones próximas de freeCodeCamp. + + +
En esta charla Rafael Hernández nos cuenta cosas muy relevantes sobre la organización de esta comunidad. Desde su propia historia y la de Quincy Larson, además también de todo lo relacionado con los contenidos y la dirección estratégica de freeCodeCamp en la parte de idiomas.
+ + + + + + + +Agradecer la atención y la disponibilidad de Rafael y Quincy para realizar esta entrevista. Os animamos a visitar los enlaces que nos deja Rafael y a participar en la comunidad de aprendizaje en línea de freeCodeCamp. Por último, animar a todo el mundo a crear contenidos en español o a colaborar con el proyecto con alguna aportación económica.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
-
+
-
Construye tu contenido en internet con independencia de las plataformas
-Podcast República Web 18 11 2019
+Serving our customers more effectively with new release cycles for Microsoft Edge
+Microsoft Edge Blog 12 03 2021
Innovation has been part of Microsoft Edge since day one, whether you’re seamlessly accessing corporate apps online for work or saving money shopping with built-in coupons. As contributors to the Chromium project, we look forward to Serving our customers more effectively with new release cycles for Microsoft Edge appeared first on Microsoft Edge Blog.
+
-
+
-
Itinerario de Desarrollador Frontend
-Podcast República Web 16 09 2019
+Evercade and The Oliver Twins raise over £11.000 for the National Videogame Museum
+Evercade 12 03 2021
Evercade, Codemasters and The Oliver Twins are delighted to share the news of the first donation to the National Videogame Museum. Following the launch of The Oliver Twins Collection cartridge, exclusively for the Evercade Retro Gaming console, it was announced that all profits from this would be donated to the National Videogame Museum in Sheffield.... View Article
+The post Evercade and The Oliver Twins raise over £11.000 for the National Videogame Museum appeared first on Evercade.
+
-
+
-
¿Qué deberíamos exigir a un contratista en un desarrollo web?
-Podcast República Web 04 08 2019
+EL VALOR DE LA AMISTAD EN EL ESTOICISMO
+Diario Estoico 12 03 2021
-
+
-
Los podcasts que escuchamos en República Web
-Podcast República Web 26 07 2019
+Build images on GitHub Actions with Docker layer caching
+Martian Chronicles, Evil Martians’ team blog 11 03 2021
+
+
+
+ Google Cloud pierde mucha pasta y más noticias sobre hardware y sistemas
+República Web 10 03 2021
+Nueva edición de Informe Nube con David Vaquero y Antony Goetzschel. Un episodio dedicado a repasar una colección de noticias recientes sobre las tecnologías cloud, hardware y sistemas.
+ + + +Entre las noticias:
+ + + +-
+
- 00:03:28 Google Cloud pierde mucha pasta +
- 00:13:38 Filtración masiva de contraseñas +
- 00:29:12 Precios de los Threadripper Pro y placas base +
- 00:52:08 Hackean el dominio de Perl +
- 00:57:42 RoadMap de Rocky Linux +
- 01:09:53 Almalinux 8.3 beta 1 +
- 01:13:29 Liberado Longhorn 1.1 +
- 01:17:43 Comparativa Backups en la nube +
- 01:20:07 Rapid API +
- 01:22:52 Remotive.io +
- 01:31:11 Despedida +
Os recordamos que los episodios de Informe Nube también están disponibles en su formato original de vídeo, en el canal de YouTube de Cursos de desarrollo.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Digging Into CSS Logical Properties
+Ahmad Shadeed Blog 10 03 2021
+
+
+ Google Summer of Code 2021 Mentoring Orgs announced!
+Google Open Source Blog 09 03 2021
+
+
+
+
+ Microsoft Edge Legacy desktop application support ends today
+Microsoft Edge Blog 09 03 2021
+Our new modern browser, Microsoft Edge, debuted over a year ago and today can be found on hundreds of millions of devices. Last August, Microsoft Edge Legacy desktop application support ends today appeared first on Microsoft Edge Blog.
+ +
+ 
+
+
+ Masochism
+MonkeyUser 09 03 2021
+
+
+ Phil Libin: Find a new way to ski
+tonsky.me 09 03 2021
+
+
+ Quick starting is a bendy road
+Manuel Uberti 08 03 2021
+After more than a year with straight as my package manager, recently I have +decided to sit down and look closely at how I handle my Emacs packages.
+ +For all the interesting design choices and splendid documentation straight
+offers, I have never used neither its version freezing capabilities nor the
+chances to edit the source code of a package to try possible fixes before
+sending patches upstream. Two reasons, mainly:
-
+
- I update my packages on a daily basis, accepting the risk of breakages in +order to signal them to the maintainers and offer some help; +
- when I want to send a patch, I have the source code of the package I am +working on outside of my Emacs configuration to avoid leaving something messy +around. +
These are not issues with straight, of course. It all depends on what one needs
+from their package manager.
One of the major benefits that straight brought to my setup is a boost in
+startup speed. However, why don’t give package-quickstart a try? Setting
+package-quickstart to t instructs package.el to pre-compute an autoload
+file so that the activation of packages can be done much faster, resulting in a
+faster startup1. And indeed it does, resulting in more or less the same 0.4
+seconds that I was getting with straight.
One thing to be aware of is that, as the documention of package-quickstart
+suggests, “the use of ‘package-quickstart-refresh’ every time the activation
+need to be changed, such as when ‘package-load-list’ is modified” is required.
+Hence, I added an :after-while advice to package-menu-execute (bound to
+x in Package Menu) to make sure package-quickstart-refresh is run
+after every upgrade.
Again, mine is not an argument against straight. It’s still a great package
+manager and a fantastic alternative to the built-in package.el. However, these
+days my Emacs interactions do not need the fine-grained control straight
+provides.
Notes
+ +
+
+
+ -
+
-
+
See the relevant commit. ↩
+
+
+
+ Quick starting is a bendy road
+Manuel Uberti 08 03 2021
+After more than a year with straight as my package manager, recently I have +decided to sit down and look closely at how I handle my Emacs packages.
+ +For all the interesting design choices and splendid documentation straight
+offers, I have never used neither its version freezing capabilities nor the
+chances to edit the source code of a package to try possible fixes before
+sending patches upstream. Two reasons, mainly:
-
+
- I update my packages on a daily basis, accepting the risk of breakages in +order to signal them to the maintainers and offer some help; +
- when I want to send a patch, I have the source code of the package I am +working on outside of my Emacs configuration to avoid leaving something messy +around. +
These are not issues with straight, of course. It all depends on what one needs
+from their package manager.
One of the major benefits that straight brought to my setup is a boost in
+startup speed. However, why don’t give package-quickstart a try? Setting
+package-quickstart to t instructs package.el to pre-compute an autoload
+file so that the activation of packages can be done much faster, resulting in a
+faster startup1. And indeed it does, resulting in more or less the same 0.4
+seconds that I was getting with straight.
One thing to be aware of is that, as the documention of package-quickstart
+suggests, “the use of ‘package-quickstart-refresh’ every time the activation
+need to be changed, such as when ‘package-load-list’ is modified” is required.
+Hence, I added an :after-while advice to package-menu-execute (bound to
+x in Package Menu) to make sure package-quickstart-refresh is run
+after every upgrade.
Again, mine is not an argument against straight. It’s still a great package
+manager and a fantastic alternative to the built-in package.el. However, these
+days my Emacs interactions do not need the fine-grained control straight
+provides.
Notes
+ +
+
+
+ -
+
-
+
See the relevant commit. ↩
+
+
+
+ How the ARPANET Protocols Worked
+Two-Bit History 08 03 2021
+
+
+
+
+ Conseguir un sencillo efecto de desplazamiento (scroll) para cualquier navegador con polyfill
+Javier Archeni 07 03 2021
+
+
+
+
+ Llamen al de seguridad con Néstor Angulo de Ugarte
+República Web 06 03 2021
+Justo después de un año desde su participación en otro episodio del podcast, volvemos a hablar con Néstor Angulo de Ugarte. En esta ocasión aprovechamos la sección de seguridad del informe de O’Reilly Media para tratar sobre las amenazas de seguridad en internet, hablamos también de WAF (Web Application Firewall), de educación sobre ciberseguridad y también sobre su trabajo diario en GoDaddy defendiendo aplicaciones y sitios web.
+ + + +Néstor Angulo es un profesional de la seguridad muy interesado en todo lo relativo a la tecnología. Ofrece charlas con frecuencia sobre seguridad informática y trabaja de manera diaria solucionando problemas de seguridad en sitios web.
+ + + +Con Néstor hablamos también de certificación en seguridad, discutimos sobre privacidad en internet y sobre hacking ético. Como siempre un auténtico gusto poder compartir con él un rato en este podcast.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ February 2021 Monthly Update
+News on Clojurists Together 05 03 2021
+
+
+
+
+ Microsoft Edge 89: Delivering improved browser performance to get the job done
+Microsoft Edge Blog 04 03 2021
+Note: We’re in the process of deploying features mentioned in this post, starting with Stable 89, so it might be a little while before you see them in your channel and build.
+Nowadays, it’s not unusual
+The post Microsoft Edge 89: Delivering improved browser performance to get the job done appeared first on Microsoft Edge Blog.
+ +
+
+ Clojure 1.10.3 release
+Clojure News 04 03 2021
+
+
+
+
+
+
+Clojure 1.10.3 is a small release with the following changes:
+
+
+-
+
-
+
Reverted the case error message change from 1.10.2 due to backwards compatibility concerns
+
+ -
+
Added prepl support for reader conditionals
+
+
+
+
+ Detailed changelog
+
+
+
+
+See the change log for a complete list of all changes in Clojure 1.10.3.
+
+
+
+
+ Terraform en Amazon Web Services
+República Web 03 03 2021
+David Vaquero y Antony Goetzschel vuelven con su Informe Nube, con una sesión completa sobre Terraform en Amazon Web Services. En este extenso episodio nos cuentan todo lo que debes tener en cuenta para gestionar Terraform en AWS. Explican conceptos básicos como son la gestión de credenciales, la creación de buckets S3, conocer las VPC (redes privadas virtuales en la nube) y el servicio de gestión DNS de AWS Route 53.
+ + + +Esta primera parte ofrece una buena base para tratar Terraform sobre la tecnología de Amazon Web Services. Recuerda que este episodio es una versión en audio de los vídeos disponibles en el canal de YouTube de Cursos de Desarrollo.
+ + + +Contenidos del episodio:
+ + + +00:00:00 Intro
00:00:11 Sumario
00:03:06 Credencias IAM a AWS
00:16:57 Creación de un Bucket S3
00:19:08 Explicación VPC en AWS
00:25:24 Route 53
00:27:49 Seguimos con Bucket S3
00:42:07 Terraform con AWS y S3
00:59:30 Creación de la VPC
01:24:18 Security Groups y Reglas de red
01:29:33 Definición máquina EC2
01:42:07 Manejo de user_data
01:48:11 Alta disponibilidad
01:54:34 Volumen compartido EFS
02:09:14 Fe de Erratas
02:11:08 Despedida y novedades
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Season of Docs 2020: 5 Technical communication learnings as an open source contributor
+Google Open Source Blog 03 03 2021
+
+
+ Exciting New Features in Django 3.2
+Haki Benita 02 03 2021
+Django 3.2 is just around the corner and it's packed with new features. Django versions are usually not that exciting (it's a good thing!), but this time many features were added to the ORM, so I find it especially interesting!
+
+
+ PRESS: Hardware hacker and academic Nadya Peek to keynote LibrePlanet 2021
+FSF News 02 03 2021
+
+
+ Clojurists Together board nominations and annual members meeting
+News on Clojurists Together 02 03 2021
+
+
+ SoD and technical documentation in an open source organization
+Google Open Source Blog 02 03 2021
+
+
+
+
+ La importancia de elegir una herramienta SEO adecuada
+No sin mis cookies 02 03 2021
+Una cosa que está clara y es que para hacer SEO necesitas hacerte con herramientas que te ayuden en la tarea de recopilar datos para analizar y medir resultados, entre otras funciones.
+The post La importancia de elegir una herramienta SEO adecuada appeared first on No sin mis cookies.
+ +
+
+
+
+ The Most Ill-Timed Website in History
+The History of the Web 02 03 2021
+There are a near infinite number of sites that have launched that you've never heard about. This is likely one of them. But if not for poor timing, it may have been primed for success.
+The post The Most Ill-Timed Website in History appeared first on The History of the Web.
+ +
+ 
+
+
+ Promotion
+MonkeyUser 02 03 2021
+
+
+ Things I wish I knew when I started in elixir development
+(ノ°Д°）ノ︵ ┻━┻ 01 03 2021
+
+
+ Things I wish I knew when I started in elixir development
+(ノ°Д°）ノ︵ ┻━┻ 01 03 2021
++These are some things I commonly use in my elixir development workflow that might be interesting for someone.
+
+
++Managing multiple versions of elixir and erlang +
+
+
+
+When you have to work in more than one project at time that could probably means you have to handle different elixir and erlang versions so installing the default version that your OS provides won't be helpful. Here is where asdf shines to solves this problem, asdf allow us to have different versions of elixir, erlang and other languages in the same machine so we can easily switch between them.
+In macOS you can install it with brew install asdf and then follow the instructions that the installer prints out to set up the PATH, more info in its Github page https://github.com/asdf-vm/asdf
+Now we have asdf installed we need to install the plugins to handle erlang and elixir, we can install them with:
+
+
+asdf plugin add erlang
+asdf plugin add elixir+Once we have those installed we need to define which versions we're going to use in our project, there is more than one way to do that:
+
+
++Using environment variables +
+
+
+
+We can set up the required versions by defining environment variables with the ASDF_ prefix so if we need version elixir 1.10 we need to define the variable ASDF_ELIXIR_VERSION with the value 1.10 the same applies for erlang or other programming languages as well.
+For example we can define variables for elixir and erlang as the example below:
+
+
+
+export ASDF_ELIXIR_VERSION=1.10.3-otp-22
+export ASDF_ERLANG_VERSION=22.3++To handle environment variables in a easy way we can use direnv, it allows to define environment variables in a file
+.envrcand it will loaded automatically as soon as we enter to out project folder.
+
++File based config file +
+
+
+
+asdf allow us to define a .tool-versions file where we can put all the versions needed for our project, we can define one as the example below:
+
+
+erlang 23.0.2
+elixir 1.10.4-otp-23
+
++Creating a new project +
+
+
+
+Because we have first to define the versions used in a project we can't just run mix new my_app because asdf doesn't know yet which versions we want. To do this we have 2 options:
-
+
-
+
Define global versions of elixir and erlang using for example
+asdf global elixir 1.9.0and the same for erlangasdf global erlang 22.3and then we can executemix new my_appnormally
+ -
+
Define the versions just for the
+mix newcommand execution, for exampleASDF_ELIXIR_VERSION=1.9.0 ASDF_ERLANG_VERSION=22.3 mix new my_app, this way we don't affect the global scope and then we can define these same versions inside the created project.
+
I like the second one because I don't have to change the global version each time I want to create a new project and I can easily access to that command from bash history.
+
+
++Notes about erlang compilation +
+
+
+
+asdf uses kerl under the hood to handle erlang compilation and when we are installing a new version it will ask for a java installation 😕, to avoid this behaviour we can define the following environment variable:
+
+
+export KERL_CONFIGURE_OPTIONS="--disable-debug --without-javac"
+
++Ecto database url +
+
+
++If we are dealing with databases in our project we will probably be using Ecto. And Ecto allow us to define database credentials in two ways, the first one is define them separately as the example below:
+
+
+
+config :my_app, Repo,
+ database: "ecto_simple",
+ username: "postgres",
+ password: "postgres",
+ hostname: "localhost"+And the second one is using a unique parameter:
+
+
+
+config :my_app, Repo,
+ url: "postgres://postgres:postgres@localhost/ecto_simple"+This is my favorite option for these reasons:
+-
+
-
+
Just one value to maintain
+
+ -
+
This format is also accepted in
+psql, for example we can executepsql postgres://postgres:postgres@localhost/ecto_simpleand we're connected to the database. I just discovered this a few weeks ago 😅
+ -
+
We can change credentials for example when we're running a mix command just prepending the value
+DATABASE_URL=postgres://postgres:postgres@localhost/test_db mix somethingin the case we're loading it from an environment variable
+
Then if you have the connection url in a variable called DATABASE_URL, using direnv of course 😉, you can just execute psql $DATABASE_URL to database session.
+
++Using iex +
+
+
+
+
++Enable shell history +
+
+
+
+A cool feature of elixir is iex, you can load modules, recompile them and so on, but when sometimes we execute "large" pieces of code or some cases that we're trying out to understand the code or something else and when we have to restart the session we lost all the history 😢, we can avoid this by adding a flag -kernel shell_history enabled in the environment variable ERL_AFLAGS before we start our iex session. I just put following code in my .zshrc to have it enabled for all my projects:
+
+
+export ERL_AFLAGS="-kernel shell_history enabled"
+
++Preload aliases +
+
+
+
+Another thing than could be annoying to deal with is aliasing a large module name, for example if we have MyApp.Contexts.Authentication.User and we are using this module pretty often it could be easier to have it already loaded when we start a iex session, we can make this by defining a .iex.exs file in the project root with the desired aliases, for example:
+
+
+alias MyApp.Contexts.Authentication.User
+And now when we start a new iex session we will have that module aliased from the beginning so we can use User.whatever without a problem.
++Keep in mind that even if we can make an alias(a module name is just an atom) when we starting a session using just
+iexwe cannot access to its functions. We need to start ouriexsession usingiex -S mix
+
++Recompiling modules +
+
+
+
+Within a iex sessions we can recompile a module just writing r module_name and if the want to recompile the whole project we can execute recompile, this is useful when we are making some changes in the code and we need to test it right away with all the values that we already had defined. It's also called "REPL based development" and it's most used with lisp based programming languages but having iex in elixir we can use those nice features as well.
+
++Mix tasks +
+
+
+
+These are tasks that mix can run, duhh.. But we can create them and use them in our projects. For example maybe we are debugging some code and we don't want to execute a long process(business process) instead of that we can just extract some function calls and execute them from a mix task using existing data. We can create a mix task with the following code:
+
+
+defmodule Mix.Tasks.Foo do
+ @moduledoc false
+ use Mix.Task
+
+ def run(_args) do
+ Application.ensure_all_started(:my_app)
+ IO.puts("runnning...")
+ end
+end
+We have to name this file foo.ex and place it inside lib folder and now we can run mix foo and we'll get a running... message.
+I use this many times, actually I have some defined tasks in many projects than I reuse to debug some workflows.
+++I know that we "should" be defining the cases that we are debugging in a test, run it and then try to fix the code and then run the tests again but this way works for me so I'm OK with that 🙃
+
+
+
+ +Working with local third party libraries +
+
+
++In some cases we could found some weird behaviour, a bug of just want to know a little more deep about how a third party library works. In that case it could be difficult to setup a local version of a library that we use in our project.
+
+I remember using just pip install -e path_to_library in python and just starting to changing the library code.
+In elixir when we want to install a local version of a library we can specify the path of it in the mix.exs file, for example:
+
+
+defmodule MyApp.MixProject do
+ use Mix.Project
+
+ def project() do
+ [
+ app: :my_app,
+ version: "0.0.1",
+ elixir: "~> 1.0",
+ deps: deps(),
+ ]
+ end
+
+ def application() do
+ []
+ end
+
+ defp deps() do
+ [
+ {:ecto, "~> 2.0"},
+ {:postgrex, "~> 0.8.1"},
+ {:ecto_sql, path: "ecto_sql_local_path"}
+ ]
+ end
+end
+In this case we're telling our project to install ecto_sql from the given path, this will work but just the first time because it will load and compile ecto_sql at the beginning and then when we're making some changes in the code placed in ecto_sql_local_path these changes won't be recompiled automatically because mix is only watching for changes inside our project. In this case we can force to recompile some modules by using for example r Ecto.Migrator from within an iex session but if we are modifying more modules it would be tedious to recompile manually every one of them, for this case we can define a Recompiler module that make this work for us, name it as you want, this will contains:
+
+
+defmodule Recompiler do
+ def run do
+ modules_to_recompile = [
+ Ecto.Migrator,
+ Ecto.SomeOtherModule
+ ]
+
+ for module <- modules_to_recompile do
+ IEx.Helpers.r(module)
+ end
+ end
+end
+We can place this module somewhere inside our lib folder and when we call Recompiler.run from within a iex session it will recompile all the defined modules.
+
+ Activate python virtualenv automatically with direnv
+(ノ°Д°）ノ︵ ┻━┻ 01 03 2021
+
+
+ Activate python virtualenv automatically with direnv
+(ノ°Д°）ノ︵ ┻━┻ 01 03 2021
+
+direnv is a tool to set up automatically environment variables as soon as we enter in a directory that contains a .envrc file. We can use this feature to activate our virtualenvs as well.
+Let's see what happens when we activate manually a virtualenv with source ./env/bin/activate:
-
+
-
+
A new new environment variable called
+VIRTUAL_ENVis exported.
+ -
+
The path is updated to include the
+bindirectory inside ourvirtualenvthis is made to allow us to point to the correct python installation and run cli interfaces exposed by the dependencies we have installed.
+
Because all the "magic" about activating a virtualenv is basically configuring some environment variables we can do it automatically using direnv.
+Let's assume we have a virtualenv installed in the path /Users/erick/.virtualenvs/demo, the virtualenv is located inside ~/.environments because I'm using virtualenvwrapper but it can be in any other location. Now we can use this location to configure our .envrc file as the following:
+
+
+export VIRTUAL_ENV=/Users/erick/.virtualenvs/demo
+export PATH=/Users/erick/.virtualenvs/demo/bin:$PATH+Now when we enter our project folder the virtualenv will be "activated" automatically and when we leave the project folder it will be "deactivated".
++Also when we use this method is easiest for our editor(emacs in my case) to recognize the current python installation and be able to run tests, execute files, etc.
+ +
+
+ January 2021 Monthly Update
+News on Clojurists Together 28 02 2021
+
+
+ December 2020 Monthly Update
+News on Clojurists Together 28 02 2021
+
+
+ Find file under cursor in emacs
+(ノ°Д°）ノ︵ ┻━┻ 27 02 2021
+
+
+
+
+ Front-end insatisfecho es mi profesión
+República Web 27 02 2021
+La velocidad de los cambios en el ámbito del front-end, ha generado una sensación de hastío o insatisfacción entre los profesionales del diseño web. No son pocos los profesionales que expresan su descontento con la complejidad o la sobre ingeniería que ha sufrido la capa de presentación de los sitios web. En este episodio nos hacemos eco de este sentimiento, a través de otro acertado artículo de Chris Coyier titulado Front-End Dissatisfaction (and Backing Off), que a su vez hace referencia a otros artículos similares.
+ + + +Muchos profesionales ven con escepticismo las ventajas de aplicar las últimas tecnologías a su stack de herramientas. A fin de cuentas, como se explica la web sigue funcionando con HTML y CSS, y la progresiva incorporación de frameworks y otras herramientas, diluye la sencillez del medio. Existe una presión en ocasiones infundada, por estar al día en las últimas tendencias, a menudo también debido al temor de no quedarse atrás en la carrera o mercado profesional. En el episodio comentamos este artículo sobre la evolución del front-end y nuestra opinión acerca de cómo afrontar tanto cambio.
+ + + +En la segunda parte del episodio volvemos (min 36:30) con la sección Backlog, donde contamos recientes experiencias relacionadas con nuestro trabajo. Hablamos sobre una aplicación de citas que le solicitaron desarrollar a Andros y también de lo poco profesional que resulta dejar textos «lorem ipsum» en una web publicada.
+ + + +Por último vuelve también (min 50:43) la sección Radar al podcast con algunos enlaces de recursos y herramientas de interés, relacionadas con el desarrollo web.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ My Home Office
+Blogs on Tom Spencer 27 02 2021
+
+
+ My Home Office
+Blogs on Tom Spencer 27 02 2021
+
+
+ DuckDuckGo logo redesign
+tonsky.me 26 02 2021
+
+
+ CSS: @media para detectar dispositivo táctil
+Bufa 24 02 2021
+
+
+ Embracing modern image formats
+Josh Comeau's blog 24 02 2021
+
+
+ Macs and 4K 120Hz displays compatibility list
+tonsky.me 24 02 2021
+
+ 
+
+
+ Time To Merge
+MonkeyUser 23 02 2021
+
+
+
+
+ Eleventy es mucho más que un generador de sitios web estáticos
+Javier Archeni 22 02 2021
+
+
+
+
+ Aprendiendo Rust con Lorenzo Carbonell (Atareao)
+República Web 21 02 2021
+Rust es un lenguaje de programación de sistemas orientado a crear aplicaciones de alto rendimiento. Las principales ventajas de Rust son su enfoque en la velocidad, su entorno seguro de ejecución en memoria y la concurrencia. Usado por las principales empresas de tecnología como Google, Mozilla, Dropbox o Microsoft, Rust sigue apareciendo año tras año entre los lenguajes más apreciados por la comunidad de desarrollo.
+ + + +Rust ha dado origen a un montón de proyectos innovadores que van desde sistemas operativos, motores para juegos, controladores y bases de datos. Rust soporta WebAssembly, un entorno de ejecución que permite desplegar aplicaciones nativas en el navegador sin necesidad de JavaScript, por cierto creado también en Mozilla. WebAssembly permite compilar y desplegar tus proyectos Rust a servidores, dispositivos IoT, móviles y al navegador.
+ + + +Aunque Rust sea visto como un lenguaje de sistemas más situado en reemplazar a C y C++, en ámbitos como sistemas operativos o librerías nativas, muchos desarrolladores de Rust están trabajando en gran medida en backends para la creación de aplicaciones web. No es por tanto extraño que frameworks web como Hyper, Actix y Rocket se encuentren entre los proyectos más populares entre los desarrolladores de Rust.
+ + + +Para este episodio invitamos a Lorenzo Carbonell, más conocido por la comunidad como Atareao. Lorenzo es un gran divulgador de las tecnologías de código abierto y especialista en GNU/Linux y Android. A través de su web atareao.es y su podcast, Lorenzo comparte valiosa información sobre infinidad de tecnología y también sus proyectos. Precisamente no hace mucho, Lorenzo contaba que había decidido aprender Rust, así que nos ofrece una gran excusa para invitarlo al programa para hablar sobre este lenguaje.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ The styled-components Happy Path
+Josh Comeau's blog 21 02 2021
+
+
+ Basis Universal Textures - Khronos Ratification and <model-viewer> Support
+Google Open Source Blog 18 02 2021
+
+ 
+
+
+ Fractals in WebAssembly, Async Iteration for Node.js Streams, TDD, Scroll to Text Fragment, and Immutable code 🥺 — Pony Foo Weekly
+Pony Foo Weekly 18 02 2021
+
|
|
|
|
|
|
+
+ A new resource for coordinated vulnerability disclosure in open source projects
+Google Open Source Blog 17 02 2021
+
+
+
+
+ Qué es la afinidad en los enlaces y para qué nos sirve en SEO
+No sin mis cookies 17 02 2021
+Ante todo, agradecer a Carlos de No sin mis cookies el poder escribir en este blog. Para quien no me conozca, mi nombre es David Ayala y llevo trabajando en el mundo del SEO desde el año 2003. Soy un amante del link building y de los enlaces y por ello hoy he venido a ... Read more
+The post Qué es la afinidad en los enlaces y para qué nos sirve en SEO appeared first on No sin mis cookies.
+ +
+
+
+
+ Serverless TypeScript: A complete setup for AWS SAM Lambdas
+Martian Chronicles, Evil Martians’ team blog 17 02 2021
+
+
+
+
+ IRA, ENFADO Y ESTOICISMO: DOMA EL DRAGÓN
+Diario Estoico 16 02 2021
+
+
+ Riding the Struggle Bus that was the Table of Contents
+blog.karenying.com 16 02 2021
+
+ 
+
+
+ Adoption
+MonkeyUser 16 02 2021
+
+
+
+
+ La salud de internet en el 2020 según Mozilla
+República Web 13 02 2021
+Vuelve el Internet Health Report de Mozilla al podcast en su edición 2020. En este episodio hablamos de los puntos principales que se tratan en este último informe de la Fundación Mozilla. El informe anual compila investigaciones e historias que buscan sugerir cómo internet podría ser más saludable en todo el mundo. En su última edición el informe Mozilla apunta como es ineludible, a la pandemia como uno de los factores que ha influido en el uso de internet. En otros puntos, sigue centrado en la necesidad de garantizar un acceso libre y universal a la red, el poder las grandes tecnológicas, los movimientos sociales y la búsqueda de un equilibrio que ayude a explorar la doble naturaleza de internet, la saludable y la no saludable.
+ + + +Como en otras ediciones, se trata de un informe largo, con diferentes fuentes y apoyado con ilustrativos gráficos. En el episodio nos limitamos a contar lo que nos ha parecido más destacable, con especial mención a cuestiones educativas, la desinformación y el poder las grandes compañías de internet.
+ + + +Os animamos a visitar la web de la Fundación Mozilla, donde poder consultar toda la información disponible y explorar los vínculos a las noticias y estudios que complementan este informe 2020. También se puede descargar en formato PDF o ePub.
+ + + ++ + + +SORTEO Libro Python ? La editorial @EdicionesENI colabora con el podcast ofreciendo algunos de sus títulos Consigue el libro online Python 3 haciendo RT de esta publicación #sorteoLibroPythonRW y siguiendo a @EdicionesENI @republicawebes Hasta 20/02 12pm https://t.co/gBhCzb3EoN pic.twitter.com/fpB6EehX4w
— Podcast República Web (@republicawebes) February 13, 2021
En este episodio también damos la bienvenida a la editorial de libros informáticos Ediciones ENI, que como colaboración con el podcast ofrece el acceso a algunos de sus libros. Este acceso se brindará a las personas que vayan ganando los concursos que periódicamente realizaremos en el podcast.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
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+ React Performance, Effortless Web Security, TypeScript Unions, WebAssembly, and MORE! 🤪 — Pony Foo Weekly
+Pony Foo Weekly 12 02 2021
+
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+
+ Updates on the Tsunami Security Scanning Engine
+Google Open Source Blog 10 02 2021
+
+
+ The 2021 Season of Docs application for organizations is open!
+Google Open Source Blog 09 02 2021
+
+
+ CSS: múltiples :not()
+Bufa 09 02 2021
+
+
+
+
+ El «no code» cambiará la industria del software pero necesitará programadores
+Javier Archeni 08 02 2021
+
+
+ Google joins the Rust Foundation
+Google Open Source Blog 08 02 2021
+
+
+ Writing fuzz tests with ease using Bazel
+Google Open Source Blog 08 02 2021
+
+ 
+
+
+ State of the Common Lisp ecosystem, 2020 🎉
+Lisp journey 08 02 2021
+This is a description of the Common Lisp ecosystem, as of January, 2021, +from the perspective of a user and contributor.
+ +The purpose of this article is both to give an overview of the +ecosystem, and to help drive consolidation in each domain.
+ +Each application domain has recommendations for consolidating that +part of the ecosystem, and pointers for interesting future work.
+ +This article is derived from +Fernando Borretti’s State of the Common Lisp ecosystem from 2015, hence the introduction that sounded familiar. +This new one will be an opportunity to look at what was achieved, or what is +still lacking.
+ +Disclaimer: This article is not a list of every project or article of interest that came out in the last years. I wrote an overview of 2018 closer to that goal here. More libraries can be discovered on the Awesome-cl list, on GitHub and on Cliki.
+ +Acknowledgements I would like to thank @borodust, @ambrevar and @digikar for their kind feedback.
+ + + +Table of Contents
+ +-
+
- Application domains + + +
- Languages interop
+
+
-
+
- APL +
- C, C++, Objective C +
- Clojure +
- Python +
- .Net Core +
+ - Development + + +
- Community
+
+
-
+
- Online presence + + +
- New books +
- Companies +
- Growth +
+ - Last words +
Application domains
+ +Command line
+ +There used to be several options to ease building and distribution of command line programs, +but now Roswell has gained most momentum, +and that’s a good thing. Roswell is an implementation +manager, installer and a script runner, and one of its neat features is support for +very easily compiling tiny scripts into executables.
+ +Now, GNU Guix has gained many CL libraries, and becomes a contender to Roswell. Guix can be used as a package manager on top of your Unix distribution. It brings reproducible builds, rollbacks, the ability to install exact versions of any library (including system dependencies), contained environments and user profiles. It makes it easy too to install the latest version of a CL implementation and libraries and, to a certain extent, to share scripts. See the article A Lisp REPL as my main shell for insights.
+ +To parse command line arguments, unix-opts shows decent activity. As a reminder, the CLI arguments are stored portably in uiop:command-line-arguments.
Adams is a new UNIX system administration tool, not unlike Chef or Ansible.
+ +Consolidation
+ +More features to the sripting libraries.
+ +Future work
+ +The Lem editor has built a great user interface and REPL on top of ncurses, with the cl-charms library. It would be great to re-use its components, so that Lispers could easily build similar rich terminal-based interfaces.
+ +Databases
+ +Mito is an ORM for Common Lisp +with migrations, relationships and PostgreSQL support. It is based on +cl-dbi (a uniform interface to the various database server-specific +libraries such as cl-postgres and cl-mysql) and SxQL (a DSL for +building safe, automatically parameterized SQL queries).
+ +It also has a tutorial in the Cookbook: +Cookbook/databases.
+ + + + + + + +There are of course more libraries in that field. Some new ones since 2015 are:
+ +cl-yesql (by the author of +Serapeum, Spinneret and other great libraries) is based on Clojure’s +Yesql.
+ +vivace-graph is a graph +database and Prolog implementation, taking design and inspiration from +CouchDB, neo4j and AllegroGraph.
+ +Vsevolod Dyomkin, the author of Rutils, the Programming Algorithms +book and other libraries, is writing +cl-agraph, a minimal client +to Franz Inc’s AllegroGraph. AllegroGraph is a +“horizontally distributed, multi-model (document and graph), +entity-event knowledge graph technology”. It is proprietary and has a +free version with a limit of 5 million triples. Surely one of those Lisp hidden gems we should know more about.
+ +A general migration tool was lacking. We now have +cl-migratum, a “system which +provides facilities for performing database schema migrations, +designed to work with various databases”.
+ +And of course, pgloader is still a Common Lisp success story.
+ +Achievement
+ +Among the emerging ORMs, Mito is the one actively maintained that Lispers seem to have chosen. Good. CLSQL certainly still works, but we don’t hear about it and it looks outdated. So, Mito it is.
+ +Consolidation
+ +Mito has 11 contributors and is actively watched, but it probably should have another(s) core maintainers.
+ +Future work
+ +Bindings for the new databases coming out.
+ +Concurrency
+ +In the last year, Manfred Bergmann developed +cl-gserver. It is a +“message passing” library/framework with actors similar to +Erlang or Akka. It is an important achievement.
+ +Its v1 features:
+ +-
+
- actors can use a shared pool of message dispatchers which effectively allows to create millions of actors. +
- the possibility to create actor hierarchies. An actor can have child actors. An actor now can also “watch” another actor to get notified about its termination. +
Many other libraries exist in this area:
+ +-
+
- BordeauxThreads - Portable, shared-state concurrency
+
+
-
+
- the “de-facto” concurrency library. +
+ - lparallel - A library for parallel programming.
+
+
-
+
- also solid, battle-tested and popular, aka de-facto. +
+ - calispel - CSP-like channels for common lisp. With blocking, optionally buffered channels and a “CSP select” statement. ISC-style.
+
+
-
+
- “It is complete, flexible and easy to use. I would recommend Calispel over Lparallel and ChanL.” @Ambrevar. discussion +
+ - ChanL - Portable, channel-based concurrency. +
- cl-async - A library for general-purpose, non-blocking programming.
+
+
-
+
- works atop libuv +
+ - Moira - Monitor and restart background threads. In-lisp process supervisor. +
- trivial-monitored-thread - +a Common Lisp library offering a way of spawning threads and being +informed when one any of them crash and die. +
- lfarm - distributing work across machines (on top of lparallel and usocket). +
- cl-gearman - a library for the Gearman distributed job system.
+
+
-
+
- Alexander Artemenko used it instead of lfarm for Ultralisp: +https://40ants.com/lisp-project-of-the-day/2020/06/0095-cl-gearman.html, +because “lfarm is not well suited to environments where worker +hosts can go down and return back later”. +
+ - swank-crew - distributed computation framework implemented using Swank Client. +
- cl-coroutine - a coroutine library. It uses the CL-CONT continuations library in its implementation. +
- CMTX: high performance transactional memory for Common Lisp.
+
+
-
+
- In our opinion, a library not well known and under-appreciated. +
+
(see awesome-cl#parallelism-and-concurrency)
+ +Consolidation
+ +Bordeaux-Threads is the “de-facto” library, but there is some choice +paralysis between Lparallel, Calispel, Bordeaux-Threads and SBCL’s +contribs. Use the libraries in the wild and write about them.
+ +File formats
+ +There exist Common Lisp libraries for all the major file formats:
+ +-
+
- XML: Plump (and Lquery), as well as CXML, which can parse large files incrementally. +
- JSON: Jonathan, cl-json or more. With utilities:
+
+
-
+
- json-pointer - A JSON Pointer implementation. +
- json-mop - A metaclass for bridging CLOS and JSON objects (remind that JSON libraries can already serialize your own objects). +
- json-schema +
+ - YAML: cl-yaml +
- CSV: cl-csv +
Achievement
+ +New in 2015, Jonathan is now a good first choice for an easy to use and fast JSON encoder and decoder.
+ +Consolidation
+ +There is not a predominant JSON library. This leads to choice paralysis.
+ +They all represent null values differently. We need a library that +“does the right thing”. See maybe the massive web-toolkit for its JSON handling ?
+ +++ +It distinguishes null, false and [] from Lisp’s NIL thus supports identical transformation between JSON values. It provides object constructor and accessor to build and access nesting JSON objects.
+
Give the XPath library some love and documentation.
+ +Future Work
+ +Still valid from 2015:
+ +++ +A YAML parser so that cl-yaml doesn’t depend on the libyaml library would make distribution far simpler.
+
GUI
+ +A usual complain in Common Lisp land is the lack of a complete, +cross-platform GUI solution. Ltk is a very good library, but Tk is +limited. Qtools is great, but is only for Qt4.
+ +A lot has happened, and is still happening (if you watch the right +repositories, you know that a Qt5 wrapper is in the works (ECL already has Qt5 bindings: EQL5, with an Android port)).
+ +edit: see also EQL5-sailfish for Sailfish OS. Here are two example apps.
+ +Matthew Kennedy wrote excellent FFI bindings to the IUP Portable User +Interface library: IUP. IUP is +cross-platform (Windows, macOS, GNU/Linux, with new Android, iOS, +Cocoa and Web Assembly drivers), has many widgets (but less than Qt), has a small API and +is actively developed. IUP was created at the PUC university of Rio de Janeiro.
+ +Nicolas Hafner started Alloy, a +new user interface protocol and toolkit implementation, which he uses in his Kandria game.
+ +Very recently, David Botton released CLOG, “the Common Lisp Omnificent GUI”:
+ +++ +CLOG uses web technology to produce graphical user interfaces for applications locally or remotely. CLOG can take the place, or work alongside, most cross-platform GUI frameworks and website frameworks. The CLOG package starts up the connectivity to the browser or other websocket client (often a browser embedded in a native template application.)
+ +It is complete enough for most uses.
+
There are more GUI libraries and frameworks: https://github.com/CodyReichert/awesome-cl#Gui (and more under the works). In particular, LispWorks’ CAPI is still presented as the best in town by the ones who tried it.
+ +Consolidation
+ +Since roughly October, 2020, Nicolas Hafner works full time on +Kandria. Supporting his work, through GitHub +sponsors or +ko-fi would be 1) a great sign of recognition and 2) useful for the ecosystem, especially for Alloy.
+ +I wrote an introduction to these frameworks in the Cookbook: +Cookbook/gui. More +examples or demo projects would be welcome.
+ +There are two actively maintained diverged forks of the GTK bindings. A reunification effort is required.
+ +Future work
+ +Write a desktop application with IUP/your toolkit of choice for everyday use and make it a Common Lisp flagship.
+ +Study other approaches to GUI bindings. What about +gtk-server? GObject introspection? An +effort started for Qt: giqt (in +which we recognize @ambrevar from the Nyxt +browser).
+ +Machine Learning
+ +It seems that not much changed since 2015, but libraries are still being developed:
+ + + +++ +used by its author to win the Higgs Boson Machine Learning Challenge
+
-
+
- mgl-mat - a library for working with multi-dimensional arrays which supports efficient interfacing to foreign and CUDA code. BLAS and CUBLAS bindings are available. +
Others are less active:
+ +-
+
- Antik - a foundation for scientific and engineering computation in Common Lisp. It is designed not only to facilitate numerical computations, but to permit the use of numerical computation libraries and the interchange of data and procedures, whether foreign (non-Lisp) or Lisp libraries.
+
+
-
+
- more than 2000 commits, last update 2 years ago. +
+
System
+ +To quote Fernando:
+ +++ +UIOP, ASDF’s portable compatibility layer, contains a large set of tools for portably doing everything from querying the hostname to running external programs to manipulating environment variables.
+
We should not require cl-fad anymore (but we need Osicat, which unlike UIOP is POSIX friendly).
+ +Built on top of UIOP, Paul M. Rodriguez’s cmd brings in short and handy helpers to run and pipe programs.
+ +Web Development
+ +Backend
+ +Common Lisp’s main web servers are Hunchentoot and Clack. Since 2015, Clack’s documentation state barely improved and is still lacking.
+ +Clack is the equivalent of +WSGI/Rack. It has existed since 2009. It is an HTTP +server abstraction, that allows the user to write web applications +(or, more reasonably, web application frameworks) without depending on +a particular server. Some web frameworks are built on top of +it, for example Caveman2.
+ +++ +The importance of using Clack cannot be understated: If you build an application directly on, say, Hunchentoot, you’re tied to Hunchentoot, and if a new, faster server – like Woo – comes out, you have to rewrite the entire application to use it. If you write a plugin for Clack – like clack-errors – it is automatically usable by all applications, regardless of framework, that are built on Clack, reducing useless duplication of code.
+ +With Clack, switching from Hunchentoot to Woo, and enjoying the incredible speedup, is a simple matter of installing libev and changing a keyword argument.
+
This still holds true, but the situation didn’t improve much. In comparison, Hunchentoot is very well documented (and you can read its documentation on a better looking readthedocs here), and it is “fast enough”.
+ +About Hunchentoot: Mariano Montone wrote easy-routes, a little but handy route handling facility on top of Hunchentoot. It brings:
+ +-
+
- dispatch by HTTP method, +
- arguments extraction from the URL path, +
- “decorators” to, for example, quickly add authorization checks, +
- integration with the Djula framework to generate URLs from route names. +
Achievement
+ +Several Clack plugins +were written, such as a single-sign on middleware.
+ +Consolidation
+ +Write more documentation for Clack. While Lispers know about it, +they don’t necessarily adopt it because of the lack of +documentation. We can expand this getting started +guide.
+ +Future work
+ +Build a batteries-included framework.
+ +Frontend
+ +Many HTML generators and template libraries exist (see the list below). However, some new and good ones appeared lately:
+ +-
+
- TEN, by Djula’s maintainer, brings the completness of Djula with the usability of Eco (by Fernando Borretti), aka: you write Django-like HTML templates but you can interleave any Lisp code. +
- markup - a JSX-like templating engine, where HTML tags are Common Lisp code. Comes with an Emacs package. +
Other HTML generators and templating engines include:
+ +-
+
- spinneret - Common Lisp HTML5 generator. +
- cl-who - The venerable HTML generator. +
- Djula - A port of Django’s template engine to Common Lisp. +
- cl-closure-template - Implementation of Google’s Closure templates. [LLGPL][8]. +
- clip - An HTML template processor where the templates are written in HTML. +
We have nice other building blocks, such as a nice form handling +library (cl-forms) and +libraries to create Open-API interfaces. An integrated, opinionated +all-in-one solution could be a productivity boom.
+ +Consolidation
+ +Djula is easy to work with. It could do with more built-in filters.
+ +As in 2015:
+ +++ +The foundation is finished, now it’s time to write higher-level layers. An extensible administration framework for Clack applications, like Django’s Admin, would be a good example.
+
JavaScript
+ +The two “historical” Common Lisp to JavaScript compilers are:
+ +-
+
- Parenscript, a DSL that compiles a subset of Common Lisp to idiomatic JavaScript, and +
- JSCL, a CL-to-JS compiler designed to be self-hosting from day one. JSCL is not complete (yet), it lacks CLOS, format and loop. +
Two new are in development:
+ +-
+
- Valtan, a CL to JS compiler. +
- JACL, JavaScript Assisted Common LispIt has a recording from ELS 2020. +
Consolidation
+ +Help develop one of the existing CL-to-JS implementations. Why not have a look at +JSCL’s issues?
+ +Bring some new macros to ParenScript for new JavaScript idioms, as Paren6. For example, allow to write async and await.
Isomorphic web frameworks
+ +Weblocks is an already old framework that allows to write dynamic web +applications without writing JavaScript (it isn’t as dynamic as modern +JS frameworks, there is no “double data binding”). Its server-based +components use Ajax if available or fallback to plain HTTP and +update the DOM. It is a framework in the vein of Smalltalk’s Seaside.
+ +Weblocks was getting old and unmaintained but Alexander Artemenko greatly updated and refactored it in his Reblocks branch. He uses it for the Ultralisp website, and more apps. You can reach users and developers on Gitter.
+ +Recently, a very new web framework appeared: +ISSR, for Interactive +Server-Side rendering. It links a client to the server with a +websocket connection and updates the DOM selectively. It is thus not +unlike Phoenix’s LiveView or +Hotwire.
+ +See this todo-app tutorial.
+ +Achievement
+ +Reviving Weblocks and releasing CLOG and ISSR are great achievements. However, work is only started to create a community of users around them.
+ +Languages interop
+ +New solutions arose to interoperate with other runtimes.
+ +APL
+ +April brings the APL programming language (a subset thereof) to Common Lisp. Replace hundreds of lines of number-crunching code with a single line of APL.
+ +C, C++, Objective C
+ +We had CFFI (a portable foreign function interface for CL), C2FFI (Clang-based FFI wrapper generator), then cl-autowrap, a c2ffi-based wrapper generator that makes creating C bindings real quick.
+ +Pavel Korolev is developing CLAW, started as a fork of cl-autowrap, which brings C++ support. For practice he generated bindings to GLM or to the Filament rendering engine.
+ +Achievement
+ +It will be a great achievement when CLAW is officially ready to use. This is not yet the case (though the GLM bindings basically do their hello world on Android, which is an achievement per se).
+ +Clojure
+ +ABCLJ provides a “dead easy Clojure to Common lisp interop”:
+ +++ +instead of rewriting the whole Clojure langugage on CL I’m embedding ABCL in Clojure. Since both are implemented in Java and Clojure has an awesome java interop is easy to have full access on the ABCL Common Lisp environment. This way we have complete support for both Clojure and Common Lisp.
+
But why?
+ +++ +The reason I wanted to see Clojure and Common Lisp working with each other was to use CL programs/libraries on Clojure, especially Maxima and ACL2. Since ABCL already compiles and runs Maxima it should be possible but we are very far from it 🤷.
+ +There are others of attempts to shorten the gap between clojure and common lisp like Cloture and clclojure. Once they are complete Clojure will benefit from native binaries and excelent compilers like SBCL, however they are far from complete.
+
On the topic, see this talk by Alan Dipert: “Common Lisp for the curious Clojurian”.
+ +Abstract:
+ ++ +
++ +“If I had to be stranded with something other than Clojure, I’d be happiest with a good Common Lisp and its source code.” - Rich Hickey, 2011
+
Common Lisp (CL) and Clojure are both dialects of Lisp. Rich Hickey, the creator of Clojure, learned CL and used it professionally before creating Clojure.
+ +What can Clojure do that CL can’t, and vice versa? Why would anyone use CL today, when both Clojure and ClojureScript exist?
+ +In this talk, I will try to answer these questions and more, from the perspective of a long-time Clojurian with a growing passion for CL.
+ ++ +
Python
+ +py4cl is the new lib in town. It allows Common Lisp code to access Python libraries. It is basically the inverse of cl4py.
+ +See also async-process and, +while we’re at it, my comparison of Python VS Common +Lisp, where we look at the differences of workflows and +ecosystems.
+ +Achievement
+ +Calling to Python and hooking into its ecosystem is easier than ever.
+ +Future work
+ +Improving CL libraries such as +Numcl (a Numpy clone) is what’s +required to drive Common Lisp forward.
+ +.Net Core
+ +Bike is a cross-platform .Net Core interface.
+ +Development
+ +Implementations
+ +All implementations saw new releases, except CLisp, whose development however continues.
+ +Active implementations include: ABCL, CCL, CLASP, ECL, LispWorks, AllegroCL, SBCL. And to a certain extent, GNU CLisp, SICL (which is the newest one) and Corman Lisp (a CL development environment for Windows) (regenerated here).
+ +ABCL jumped to v1.8.0 to support openjdk15.
+ +SBCL still ships monthly releases. It turned 20 and keeps improving (RISC-V port, M1 port, block compilation, more compile-time type checking…). We can read a blog on the party held in Vienna here. Did you know that Doug Katzman of Google fame contributes to SBCL?
+ +(edit:)
+ +++ + + +Doug Katzman talked about his work at Google getting SBCL to work with Unix better. For those of you who don’t know, he’s done a lot of work on SBCL over the past couple of years, not only adding a lot of new features to the GC and making it play better with applications which have alien parts to them, but also has done a tremendous amount of cleanup on the internals and has helped SBCL become even more Sanely Bootstrappable. That’s a topic for another time, and I hope Doug or Christophe will have the time to write up about the recent improvements to the process, since it really is quite interesting.
+ +Anyway, what Doug talked about was his work on making SBCL more amenable to external debugging tools, such as gdb and external profilers. It seems like they interface with aliens a lot from Lisp at Google, so it’s nice to have backtraces from alien tools understand Lisp. It turns out a lot of prerequisite work was needed to make SBCL play nice like this, including implementing a non-moving GC runtime, so that Lisp objects and especially Lisp code (which are normally dynamic space objects and move around just like everything else) can’t evade the aliens and will always have known locations.
+
Editors
+ +Here too, great progress has been made. While a usual complain of non-Lispers was the lack of editor support besides Emacs (and Vim), we now nearly reach choice paralysis:
+ +-
+
- Portacle is the easiest way to get started with Emacs. It is portable and multi-platform, ready-to-use in three clicks. It ships Emacs, SBCL, Slime, Quicklisp and git. +
- SLIMA is the Atom extension. It is nearly as good as Slime for Emacs. +
- VSCode has two extensions: commonlisp-vscode, using the Language Server Protocol, and Alive, more recent, using a Lisp backend (Swank) as traditional extensions. +
- Sublime Text got a good extension: Slyblime is an implementation of SLY and it uses the same backend (SLYNK). It ships advanced features including a debugger with stack frame inspection. +
- Lem is an editor written in Common Lisp. It allows to start developing in CL at once, and it supports other languages. +
- we have a Jupyter kernel for CL. +
- the Dandelion Eclipse plugin was re-discovered. While it isn’t as feature-rich as others (no interactive debugger for example), it has its users. It specifically targets beginners. +
Last but not least, if you want to play in your iPhone or iPad, the CodePlayground app got Lisp support via CCL.
+ +Consolidation
+ +SLY might need more praise. It has sound features such as SLY stickers and the new SLY stepper.
+ +Developer utilities
+ +Life continues to improve for the developper. We will cite some new tools:
+ +-
+
- cl-flamegraph is a wrapper around SBCL’s statistical profiler to generate FlameGraph charts from Common Lisp programs. +
- tracer is a tracing profiler for Common Lisp, with output suitable for display in Chrome’s/Chromium’s Tracing Viewer. +
- GTFL is a graphical terminal for Lisp, meant for Lisp programmers who want to debug or visualize their own algorithms. It is a graphical trace in the browser. +
- Lisp REPL core dumper is a portable wrapper to generate Lisp cores on demand to start a REPL blazingly fast. It can preload provided systems to help build a collection of specialized Lisp cores.
+
+
-
+
- if you are used to working in different environments that require their own set of libraries, this core dumper (optionally along with SLY’s mrepl) can make switching from one another easier and faster. +
+
Package Management
+ +Quicklisp is the de-facto package manager. However, we now have:
+ +-
+
- Ultralisp, a Quicklisp distribution that builds every 5 minutes. We can add our project in two clicks. +
- CLPM, a new package manager that is compatible with Quicklisp, that allows to pin exact versions of dependencies, that is usable from the command line and that supports HTTPS. +
Not forgetting Qlot, to install Quicklisp libraries relative to a directory.
+ +Last but not least, as said earlier, many CL libraries were packaged for Guix (most notably by Pierre Neidhart of Nyxt).
+ +Achievement
+ +Ultralisp solves the 1-month release schedule of Quicklisp (which is a feature, but not to everyone’s taste) and makes it straightforward and quick to publish a library. CLPM by tackling a different approach solves other Quicklisp limitations. Both are great achievements.
+ +Ultralisp also has a search box that searches a symbol on all its registered libraries. Very useful.
+ +Future work
+ +Alexander is working on allowing every Ultralisp user to create his own Quicklisp dist in a few clicks.
+ +Build System
+ +Same as 2015, ASDF is the de-facto build system.
+ +++ + + +Every project has an .asd file, called a system definition file, which defines project metadata (author, maintainer, homepage, etc.) and the components.
+ +This, to me, is one of the major selling points of Common Lisp. With languages like Python, every file imports whatever it needs, and your project becomes a massive graph of interdependent files. In ASDF, you basically list the files in your project in the order in which they are defined. Or, you can specify the dependencies between the files, and let ASDF figure out a linear ordering. The point is that dependencies are explicit, and clearly spelled out.
+
Type system
+ +Quoting Fernando:
+ +++ +There’s not much to say here, except that Common Lisp has a pretty great type system that is not exploited nearly enough.
+
And to our greatest pleasure, SBCL’s type system continues to improve. For example, SBCL 1.5.9 now gives type warnings when a slot declared type doesn’t match its initform. It continued to improve on SBCL 2.0 and onwards.
Moreover, the Coalton library is bringing a dialect of ML on top of CL, in order to write statically typed programs similar in spirit to Standard ML, OCaml, and Haskell.
+ +Consolidation
+ +Help develop Coalton.
+ +Testing, CI
+ +Fernando cited FiveAM and recommended it along with the much newer +Prove. Prove has a couple issues and is now deprecated by its author, +and its younger brother Rove is not in par yet.
+ +So, use FiveAM.
+ +Moreover, Common Lisp has good support for the CI/CD services out there.
+ +CL Foundation’s Docker images have integrated best practices over the +years and are recommended: +https://common-lisp.net/project/cl-docker-images/
+ +CI-Utils regroups +utilities for various platforms (Travis, Circle, Gitlab, Github, +Appveyor, Bitbucket, Azure) and test frameworks.
+ +We got a comprehensive blog post for GitHub actions: part1 and part2.
+ +For Travis CI, you can also see cl-travis (for ABCL, Allegro CL, SBCL, CMUCL, CCL and ECL).
+ +You will find an example for Gitlab CI on the Cookbook.
+ +Consolidation
+ +Rove or Parachute would be great alternatives if developed a bit further.
+ +Further work
+ +Integration with the CI services’ advanced features such as Gitlab’s auto DevOps.
+ +Community
+ +Online presence
+ +Common Lisp is very well documented through its standard, the Common +Lisp Hyper Spec and many books. However, we felt it was lacking good +on-line material. Good news is, the situation improved tremendously in +the last three or four years.
+ +New common-lisp.net website
+ +https://common-lisp.net was written anew. It looked dated. This is now fixed. Well done!
+ +Cookbook
+ +The Common Lisp Cookbook on GitHub got revived by many new contributors, included myself. It got many new content and a new UI. It is also now available in ePub and PDF, for free or as a “pay what you want” option.
+ +Consolidation
+ +Write content on the Cookbook. Don’t write tutorials on your blog. Everyone can help, even new Lispers (and in fact: mostly new Lispers can write content best suited to the Cookbook’s target audience).
+ +Future work
+ +Make it look world-class with a real and modern theme.
+ +Help revive the minispec ?
+ +awesome-cl
+ +The awesome-cl list saw continuous updates and is now a great solution to have an overview of the ecosystem and choose a library.
+ +One of its goals is to break choice paralysis by recommending libraries, with its “+1” marks.
+ +Consolidation
+ +Help furnish and curate it.
+ +More
+ +A first Common Lisp User survey was run, we can consult its results here on Google docs and read comments on reddit as well as feedback on the questions here.
+ +I agree with /u/defunkydrummer here:
+ +++ +Note that many, many things that people wish to see, are already available, so perhaps we, as a community, are not fully communicating the state of our ecosystem even to our insiders (!)
+
Several popular libraries have been ported to readthedocs, so the reading experience is more pleasant: https://common-lisp-libraries.readthedocs.io/.
+ +Michal “phoe” Herda organized many online Lisp meetings, and we can find the videos on Youtube: https://www.youtube.com/c/OnlineLispMeetings/videos
+ +Alexander Artemenko started lisp project of the day, a blog to review a library every day for a month, and he is now at post #219. Lately he reviewed many documentation builders for CL.
+ +On a sadder note, Quickdocs closed :(
+ +New books
+ +We got 3 new books on Common Lisp in 2020:
+ +-
+
- Programming Algorithms, originally published by Vsevolod Dyomkin on his website, then self-published in paperback and then published by Apress. +
- the Common Lisp Condition System, by Michal “phoe” Herda, was also published by himself and then by Apress. +
- The Cookbook that was made available in ePub and PDF :) +
And also:
+ +-
+
- the book Calendrical calculations, 4th edition, by Edward M. Reingold, Nachum Dershowitz, Cambridge Press. It provides Lisp sources. +
- Building Problem Solvers, by Kenneth Forbus and Johan de Kleer, MIT Press, was made available. +
Companies
+ +We now have a curated list of companies using CL: awesome-cl-companies. Before that list, the situation was embarassing:
+ +++ +Everyone says “Nobody uses Lisp” and Lispers say “Yes they do, there’s ITA, and, um, Autocad, and, uh, oh yeah, Paul Graham wrote Viaweb in Lisp!” Not very helpful for either side. It’s about time there was a better resource.
+
Peter Christensen in his first list
+ +And see also lisp-lang.org’s success stories.
+ +Some additions of this year include +GraphMetrix (automation of document extraction and publishing for construction, property and logistics), +Doremir Music Research AB (developing ScoreCloud, a music notation software: you sing, it writes the score), +Keepit (a cloud-to-cloud backup service provider), +Mind AI (an artificial intelligence engine and ecosystem), +Virtual Insurance Products Ltd (insurance MGA with a bespoke business to business web platform) or again +the Mimix Company (creators of MSL and Nebula, new tools for working with facts and documents).
+ +Growth
+ +We are able to compare the number of downloads of the 100 most popular Quicklisp libraries between 2015 and 2020:
+ +
We can observe a 3x growth in five years. Of course, these figures need to be taken with a grain of salt, what they really represent is subject to interpretation. What is the role of Continuous Integration here?
+ +Check it yourself: snippet, JSFiddle.
+ +Last words
+ +Many things are happening in the CL universe. Stay tuned!
+ ++ +
The article source.
+ +
+
+ The Why of technology
+Murilo Pereira 07 02 2021
+
+ 
+
+
+ En qué ando últimamente
+Onda Hostil 07 02 2021
+
+
+ The Real Novelty of the ARPANET
+Two-Bit History 07 02 2021
+
+
+
+
+ Tendencias en Programación, Ops, IA y Web en 2021 según O’Reilly Media
+República Web 06 02 2021
+Recientemente O’Reilly Media publicó un completo informe titulado Where Programming, Ops, AI, and the Cloud are Headed in 2021. Este informe, escrito por Mike Loukides, responsable de estrategia de contenidos en O’Reilly, ha sido realizado con datos obtenidos en su plataforma de aprendizaje en línea. Tal y como explica el responsable, este estudio está limitado a los usuarios de la plataforma, según las búsquedas realizadas, filtrando y agrupando por categorías. El objetivo consiste en detectar tendencias según el interés por encontrar ciertas materias, ofreciendo información sobre el uso de los materiales formativos, dentro de la plataforma, su crecimiento y las búsquedas realizadas en la misma.
+ + + +O’Reilly Media es una de las empresa de contenidos tecnológicos más importante a nivel mundial, y un referente para muchos profesionales del ámbito de la programación y las nuevas tecnologías. Para este episodio hemos querido compartir varios apartados del estudio y para ello, también contamos con la compañía de Antony Goetzschel.
+ + + +Como explican en el artículo, O’Reilly tuvo que cerrar su división de organización de conferencias en marzo y la reemplazó por «superstreams virtuales». O’Reilly ha experimentado un considerable aumento en el uso de la plataforma durante el último año debido a la COVID (en especial el formato de formación en vivo que creció un 96%, los libros subieron un 11% y el vídeo un 24%).
+ + + +Debido a la extensión del artículo hemos decidido limitarlo a: lenguajes de programación, operaciones, desarrollo web y por último inteligencia artificial. No obstante el artículo también aborda cuestiones como la seguridad, la nube y la privacidad. Es por eso que os recomendamos al 100% su lectura.
+ + + + + + + +Se trata de un valioso documento donde dan buenas pistas acerca de las tendencias más notables en el ámbito tecnológico. El informe contiene interesantes apreciaciones por parte de Mike Loukides, en especial las relacionadas con la IA y sus implicaciones. Aunque este informe esté limitado a los datos obtenidos en la plataforma de O’Reilly Media, su influencia y alcance, le otorga una indudable validez para comprender las tendencias más sólidas en los próximos años.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Updated Debian 10: 10.8 released
+Debian News 06 02 2021
+buster). +This point release mainly adds corrections for security issues, +along with a few adjustments for serious problems. Security advisories +have already been published separately and are referenced where available. + +
+
+ CSS: efecto Marquee
+Bufa 05 02 2021
+
+
+ Launching OSV - Better vulnerability triage for open source
+Google Open Source Blog 05 02 2021
+
+ 
+
+
+ Accidents in space, React app bugs, Color vision in Chrome DevTools, and RegExp DoS! 🛰 — Pony Foo Weekly
+Pony Foo Weekly 04 02 2021
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
|
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|
|
+
+
+
+ Descubriendo la programación funcional – Swift con Valentina Rubane
+República Web 04 02 2021
+Con este séptimo episodio cerramos esta serie especial sobre programación funcional. En esta ocasión Andros Fenollosa vuelve con una habitual de este podcast: la desarrolladora y diseñadora Valentina Rubane. Ella es compañera de Andros en Sapps, su estudio de aplicaciones web y móviles en Valencia. Valentina viene para hablar del lenguaje Swift, un lenguaje de propósito general, multiparadigma y compilado desarrollado por Apple y la comunidad de código abierto.
+ + + +Como es habitual con otros invitados en esta serie sobre programación funcional, seguiremos el habitual turno de preguntas para hablar sobre este lenguaje:
+ + + +- ¿Qué pasó por tu cabeza para meterte en la programación funcional?
- Dime algunas características que te rompieron la cabeza y te enamoraron.
- ¿Qué es Swift y cuál es su origen?
- ¿Por qué hay tanto objeto si es funcional?
- ¿Es open? ¿Quién es el autor? ¿se desarrolla por comunidad?
- ¿Qué lo hace especial respecto al resto?
- ¿Quién lo usa? ¿Para quién está orientado?
- Hablemos de MacOS. Solo podemos usarlo para hacer APP de iOS. ¿Es cierto?
- ¿Cuáles son tus frameworks favoritos?
- ¿Cuál crees que es el futuro del ecosistema?
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Know, Prevent, Fix: A framework for shifting the discussion around vulnerabilities in open source
+Google Open Source Blog 03 02 2021
+
+
+ JavaScript: contar número «pulsaciones» de una tecla
+Bufa 02 02 2021
+
+ 
+
+
+ Negligible Error
+MonkeyUser 02 02 2021
+
+
+
+
+ Cambios en los RHEL de Red Hat, AMD Threadripper, Amazon libera EKS y Elastic cambia su licencia
+República Web 01 02 2021
+Este nuevo episodio de Informe Nube, David Vaquero y Antony Goetzschel ofrecen un recorrido de diversas noticias relacionadas con la nube. Para este episodio:
+ + + +Red Hat presenta nuevos programas para acceder a los programas Enterprise. Más informacion de Red Hat Developer Program.
+ + + +AMD presenta los microprocedadores Ryzen Threadripper Pro con tres nuevas placas WRX80. Más información.
Amazon libera EKS Distro (EKS-D), una distribución basada en Kubernetes y usada por el servicio Elastic Kubernetes de Amazon para crear confiables y seguros clusters de Kubernetes. Más información en el Github de AWS.
+ + + +Elastic cambia su licencia. https://www.elastic.co/es/blog/license-change-clarification y el papel que juega AWS.
+
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ CÓMO VENCER LA PROCRASTINACIÓN CON ESTOICISMO
+Diario Estoico 01 02 2021
+
+
+ The Unexpected Find That Freed 20GB of Unused Index Space
+Haki Benita 31 01 2021
+In this article I describe the process we took to identify potential free space, and one surprising find that helped up clear up ~10GB of unused indexed values!
+
+
+ Emacs: from catching up to getting ahead
+Murilo Pereira 31 01 2021
+
+
+ video html5: «autoplay» no funciona en iphone
+Bufa 30 01 2021
+
+
+ Google Summer of Code 2021 is open for mentor organization applications!
+Google Open Source Blog 29 01 2021
+
+
+ Clojure 1.10.2 release
+Clojure News 26 01 2021
+
+
+
+
+
+
+Clojure 1.10.2 includes a number of improvements for Java interop/compatibility:
+
+
+-
+
-
+
Fixes an issue in the
+lockingmacro to satisfy more stringent Java verifiers (particularly, Graal)
+ -
+
Fix for invocation of static interface methods with primitives
+
+ -
+
+proxywas incorrectly emitting Java 5 bytecode, now will be Java 8 to match all other code gen
+ -
+
Spec now compiled to Java 8 bytecode instead of Java 5 bytecode
+
+ -
+
Many fixes for reflection, javadoc urls, Java deprecation warnings, etc
+
+
+
+Other important Clojure fixes:
+
+
+-
+
-
+
Fix
+caseexpression branch analysis resulting in compilation error
+ -
+
Fix
+nthwith not-found value on regex matcher
+ -
+
Improve
+vector-ofimpls with equals, hashing, metadata support to match other colls
+ -
+
Fix printing of some maps with namespace syntax
+
+ -
+
Various doc string and error message fixes
+
+ -
+
Perf improvement - use transients in
+zipmap
+
+
+
+ Detailed changelog
+
+
+
+
+See the change log for a complete list of all changes in Clojure 1.10.2.
+
+
+ Fullstack Adventure
+MonkeyUser 26 01 2021
+
+
+
+
+ DESAMOR DESDE EL ESTOICISMO
+Diario Estoico 24 01 2021
+
+
+ Cathedrals, Bazaars, and Fusion Reactors
+Murilo Pereira 24 01 2021
+
+
+
+
+ Descubriendo la programación funcional – Lisp con Diego Sevilla
+República Web 23 01 2021
+Sexta entrega de la travesía de descubrimiento por la programación funcional. En esta ocasión Andros invita a Diego Sevilla, profesor en la Universidad de Murcia para hablar de Lisp, uno de los lenguajes de programación más longevos y raíz de otros dialectos como Scheme, Clojure, Common Lisp o Emacs Lisp.
+ + + +Se puede asegurar que familia de Lisp tiene una larga historia que ha ayudado a modelar a otros lenguajes. Todo un pionero para lenguajes tan conocidos como Perl, Python, Javascript, Lua, Scala, Ruby, R, Elixir, Haskell… entre otros. Y que, a pesar de haber nacido en 1958 continúa gozando de salud juvenil. Lisp se puede utilizar en 10 dialectos diferentes, como por ejemplo Clojure, del que ya hablamos en el primer episodio de la serie programación funcional.
+ + + +Con Diego Sevilla hablamos mucho sobre GNU Emacs, la situación actual de Lisp, de Common Lisp, del invierno de la IA y su renacimiento, de la perenne habilidad de Lisp para continuar siendo un lenguaje valioso, altamente expresivo, con su particular sintaxis y con unas bases profundamente sólidas en conceptos matemáticos.
+ + + +Como en anteriores episodios de la serie, conversamos sobre los comienzos de Diego en la programación funcional, su uso actual, recursos de interés para conocer el lenguaje y su comunidad.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Vanilla JS: on load
+Bufa 20 01 2021
+
+
+ Vanilla JS: clonar elemento
+Bufa 19 01 2021
+
+
+
+
+ LOGRA TUS PROPÓSITOS DESDE EL ESTOICISMO
+Diario Estoico 19 01 2021
+
+
+ The Common Lisp Cookbook Is Now Available in EPUB and PDF
+Lisp journey 19 01 2021
+I am glad to announce that the Common Lisp Cookbook is now available in ePub and PDF.
+ +It is available for free, and you can pay what you want[1] to say a +loud “thank you” and to further support its development. Thanks!
+ +This EPUB represents the work on the span of three years where I have been constantly reading, experimenting, asking, discovering tips, tools, libraries and best-practices, built-in or not, all of which should have been easily accessible but were not. Now they are. Reviving the Cookbook project resonated in the community, as other lispers sent great contributions.
+ ++ Donate and download the EPUB version +
+ +=> https://lispcookbook.github.io/cl-cookbook/ <=
+ ++ +
[1]: above 6 USD actually.
+ +
+ 
+
+
+ Pending Approval
+MonkeyUser 19 01 2021
+
+
+
+
+ Los put?s amos de internet con Eduardo Collado
+República Web 17 01 2021
+Recientes acontecimientos como la expulsión conjunta en redes sociales del todavía Presidente Trump y el bloqueo global de servicios como Parler en AWS, ofrecen una excelente oportunidad para comprender mejor un aspecto fundamental del funcionamiento de Internet, ¿Quién o quiénes gobiernan internet? ¿Quién decide cómo y de qué forma se accede a la red? ¿Hay límites a lo que las grandes empresas de internet puedan decidir en materia de libertad de expresión?
+ + + +Para este episodio contamos con la compañía de Eduardo Collado, un gran profesional de las telecomunicaciones, consumado podcaster y todo un evangelista de las tecnologías de internet. Con él hablamos del poder de las operadores para inspeccionar el tráfico y de cómo podemos como usuarios, protegernos del formidable poder de las empresas de internet sobre nuestras comunicaciones.
+ + + +Con Eduardo Collado hablamos sobre de aspectos técnicos como DNS, VPN, BGP, pero en especial sobre la idoneidad de fiar nuestros datos a empresas de telecomunicaciones y grandes empresas que dominan nuestros destinos en la red.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ The values of Emacs, the Neovim revolution, and the VSCode gorilla
+Murilo Pereira 17 01 2021
+
+
+ Vanilla JS: reproducir videos html5 automáticamente al hacer scroll
+Bufa 17 01 2021
+
+ 
+
+
+ Learning new Codebases, PR Collaboration, fun with Unit Testing, GraphQL, and Maintainable React Apps! 🥦 — Pony Foo Weekly
+Pony Foo Weekly 14 01 2021
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
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+
+ State of Clojure 2021 Survey
+Clojure News 14 01 2021
+
+
+It’s time for the annual State of Clojure Community Survey!
+
+
+If you are a user of Clojure or ClojureScript, we are greatly interested in your responses to the following survey:
+
+
+-
+
- + + +
+
+The survey contains five pages:
+
+
+-
+
-
+
General info
+
+ -
+
Tool usage
+
+ -
+
Questions specific to JVM Clojure (skip if not applicable)
+
+ -
+
Questions specific to ClojureScript (skip if not applicable)
+
+ -
+
Final comments
+
+
+
+Only the first two questions are required, please skip any questions that are not applicable.
+
+
+
+ The survey will close January 29th, after which all of the data will be released with some analysis. We greatly appreciate your input!
+
+
+
+
+ Introducción a Terraform sobre Digital Ocean
+República Web 13 01 2021
+Para este segundo episodio de Informe Nube, David Vaquero y Antony Goetzschel, ofrecen una introducción a Terraform y un despliegue de una infraestructura sobre la plataforma de cloud Digital Ocean.
+ + + +Terraform es una interfaz de línea de comandos que permite gestionar cientes de servicios en la nube. Terraform codifica las API de los servicios cloud en ficheros de configuración declarativos. Esta introducción permite comprender los aspectos básicos de Terraform y se utilizan como ejemplos los servicios de Digital Ocean.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ A rabbit hole full of Lisp
+Murilo Pereira 13 01 2021
+
+ 
+
+
+ Task, Story, Epic, Quest
+MonkeyUser 13 01 2021
+
+
+ reCAPTCHA v3: ocultar insignia
+Bufa 11 01 2021
+
+
+ What's good about staying inside Emacs?
+Murilo Pereira 11 01 2021
+
+
+ Re-Introducing Hash Indexes in PostgreSQL
+Haki Benita 10 01 2021
+There is a type of index you are probably not using, and may have never even heard of. It is wildly unpopular, and until a few PostgreSQL versions ago it was highly discouraged and borderline unusable, but under some circumstances it can out-perform even a B-Tree index.
+
+
+ Hyperreals *R: Clausuras en python - Parte 2
+Python Hispano 10 01 2021
+Ámbitos anidados
+La importancia de disponer de clausuras va más allá de saber dónde se evalúa +la función. Si fuera posible encapsular una función junto con su propio entorno +de ejecución, podríamos conseguir que la función tenga “memoria” o, dicho de +otro modo, que sea capaz de conservar sus propios estados entre llamadas a la +función. Este empaquetado de función y entorno de ejecución se denomina a +veces clausuras verdaderas y suele ser la principal característica de los +llamados Lenguajes Funcionales.
+En python podemos crear estas clausuras verdaderas con *funciones anidadas, +donde una función está definida dentro del ámbito de la otra.
+Un ejemplo sencillo:
+def incr(n):
+ def aux(x):
+ return x + n
+
+ return aux
+
+
+inc5 = incr(5)
+
+print(inc5(10)) # -->15
+Como resultado se devuelve la función aux, definida dentro del ámbito de
+incr y que emplea de éste la variable n. Internamente, se conserva la
+referencia a la variable n, pero no será accesible desde fuera de la función
+aux. Hemos podido empaquetar la función junto con el entorno donde se definió.
Pongamos otro ejemplo:
+def count():
+ num = 0
+
+ def aux():
+ num += 1
+ return num
+
+ return aux
+
+
+c1 = count()
+
+c1() # --> 1
+c1() # --> 2
+c1() # --> 3
+Si pruebas este código te dará error. La función anidada aux intenta modificar
+la variable num. Para este caso, la variable se crea dentro del ámbito más
+interno, en lugar de usar la variable disponible. Y como se intenta modificar la
+variable antes de asignarle un valor, entonces se produce el error.
Como solución, podríamos hacer la variable num global para que fuera accesible
+por todos los ámbitos. Pero esta solución no es buena ya que nos abriría el
+empaquetado. Para python3 podríamos declarar la variable como nonlocal para
+que se busque en los ámbitos superiores:
def count():
+ num = 0
+
+ def aux():
+ nonlocal num
+ num += 1
+ return num
+
+ return aux
+Como solución para salir del paso, se puede evitar la reasignación de variables. +Por ejemplo, usando una lista:
+def count():
+ num = [0]
+
+ def aux():
+ num[0] += 1
+ return num[0]
+
+ return aux
+Ya sé que no es muy elegante, pero hay otras formas de hacerlo mejor.
+Generadores
+Una de las formas más comunes de usar clausuras es a través de generadores.
+Básicamente, son funciones que en lugar de usar return utilizan yield para
+devolver un valor. Entre invocaciones, se conserva el entorno de ejecución y
+continúan desde el punto desde donde estaba. Para el ejemplo anterior:
def count():
+ num = 0
+ while True:
+ num += 1
+ yield num
+
+
+c1 = count()
+next(c1) # --> 1
+next(c1) # --> 2
+Objetos funciones
+En los ejemplos que hemos visto, podríamos tener varias clausuras de una misma +función. Si hemos hecho bien las tareas, la ejecución de estas clausuras son independientes:
+c1 = count()
+c2 = count()
+
+next(c1) # -->1
+next(c1) # -->2
+next(c2) # -->1
+next(c2) # -->2
+next(c1) # -->3
+Con ello es posible establecer una analogía con clases y objetos. La definición +de la función sería la clase y la clausura la instancia de la clase.
+¿Y si lo hacemos posible? En python se denominan callables a todo objeto que
+tenga un método __call__, comportándose como si fueran funciones
+(Functores). Contruyamos una callable que funcione como una función con clausura:
class Count(object):
+ def __init__(self):
+ self.num = 0
+
+ def __call__(self):
+ self.num += 1
+ return self.num
+
+
+c1 = Count()
+c1() # -->1
+c1() # -->2
+c1() # -->3
+Sin duda es la manera más elegante de usar clausuras que tenemos en python. +Evita muchos problemas y nos da una gran potencia a la hora de resolver algunos problemas.
+Por ejemplo: imagina que queremos recorrer una lista de números, excluyendo los +que sean pares, y siempre que la suma total de los números que ya hemos visitado +no supere cierto límite.
+En una primera aproximación se podría crear un generador:
+def recorr(lista, maximo):
+ total = 0
+ for i in lista:
+ if i % 2 != 0:
+ if total + i < maximo:
+ total += i
+ yield i
+ else:
+ break
+
+
+recorr([3, 6, 7, 8, 11, 23], 30) #-->[3,7,11]
+Está bien, pero no es fácil de usar. Aunque sólo necesitemos algunos elementos,
+seguramente estemos obligados a crear una lista completa con todos los
+valores1. Encima, no tenemos acceso a la variable total para saber cuánto
+han sumado el resultado.
Una alternativa con objetos funciones, mucho más elegante:
+class RecorrFunc(object):
+ def __init__(self, maximo):
+ self.maximo = maximo
+ self.total = 0
+
+ def filter(self, item):
+ res = item % 2 != 0 and self.total + item < self.maximo
+ if res:
+ self.total += item
+ return res
+
+ def __call__(self, lista):
+ return [x for x in lista if self.filter(x)]
+
+
+recorr = RecorrFunc(30)
+recorr([3, 6, 7, 8, 11, 23]) # -->[3,7,11]
+print(recorr.total) # -->21
+Las posibilidades de los objetos función son muchas. Del mismo modo que se
+devuelve una lista, sería posible devolver un iterador. Empleando las funciones
+del módulo itertools, y algunos trucos más, podríamos aplicar los principios
+de la programación funcional en python sin problemas.
Pero éso lo veremos en próximos artículos.
+
+
+
+ +
-
+
-
+
No sabemos de antemano cuántos items vamos a obtener. Si, por ejemplo, +necesitamos sólo los tres primeros, tendremos que iterar elemento a elemento +hasta llegar a los tres que necesitamos o, bien, hasta que quede exhausto el +iterador. Con la solución con funtores el proceso es mucho más directo y +eficiente. ↩
+
+
+
+ Hyperreals *R: Clausuras en python - Parte 1
+Python Hispano 10 01 2021
+Funciones Lambda
+Antes de ver qué son las clausuras (closures), veamos qué tienen las +funciones lambda que las hacen tan polémicas algunas veces.
+Comencemos con un ejemplo. Te recomiendo que te esfuerces en deducir cómo +funciona sin ir a probar cómo funciona. A continuación te pondré algunos valores +para que elijas los valores de las tres listas:
+ i = 1
+ add_one = lambda x: x + i
+
+ lista1 = [add_one(i) for i in [0, 1, 2]]
+
+ i = 0
+ lista2 = [add_one(i) for i in [0, 1, 2]]
+
+ i = 2
+ lista3 = [add_one(i + 1) for i in [0, 1, 2]]
+Valores para lista1:
-
+
[0, 1, 2]
+[1, 2, 3]
+[0, 2, 4]
+[1, 3, 5]
+
Valores para lista2:
-
+
[0, 1, 2]
+[1, 2, 3]
+[0, 2, 4]
+[1, 3, 5]
+
Valores para lista3:
-
+
[0, 1, 2]
+[1, 2, 3]
+[2, 3, 4]
+[1, 3, 5]
+
Las soluciones están al final del artículo1, pero puedes probarlo ahora para +que lo veas tú mismo.
+¿Qué es lo que ha pasado?
+Contrariamente a lo que estamos acostrumbrados con las funciones normales, la
+evaluación de una función lambda se hace dentro del entorno donde se ejecuta,
+independiente del entorno donde se ha definido. Así pués, en la función lambda
+lambda x: x+i, la variable i toma el valor de esta variable en el momento de
+evaluar la función. Como se usa esta variable para la compresión de la lista,
+irá cambiando de valor a medida que se recorre la lista [0,1,2], por lo que la
+expresión add_one(i) termina convirtiéndose en la expresión i+i, y la
+expresión add_one(i+1) en i+1+i.
Tiene un funcionamiento similar a los macros, donde se sustituye +literalmente la llamada a la función por la expresión equivalente. En python3, +se hace más evidente al denominarse expresiones lambda en lugar de funciones +lambda.
+Clausuras
+En una función podemos distinguir dos partes:
+-
+
- Código ejecutable +
- Entorno de evaluación, más conocido por Ámbito o Scope +
Antes de ejecutar el código de la función, se aumenta el entorno de evaluación +con los argumentos de entrada de la función.
+Según en qué entorno se evalua la función, tenemos dos ámbitos:
+-
+
- Clausura, también llamado Ámbito léxico o Ámbito + Estático, cuando la función se evalua en el entorno donde se ha definido. +
- Ámbito dinámico cuando se evalua en el entorno donde se invoca la función. +
Con esta definición, podemos afirmar que en python las funciones tienen ámbito +léxico, con excepción de las funciones lambda que tienen ámbito dinámico.
+No voy a considerar las ventajas de uno u otro tipo. Por lo general, las +clausuras se consideran mejores para desacoplar el código de la función del +código donde se invoca, lo que ayuda mucho al mantenimiento y corrección de +errores. Es por ello la manera normal de crear funciones en la mayoría de +lenguajes de programación.
+¿Cómo hacer que una función lambda se comporte como si tuviera clausura?
+La forma de hacer que un función lambda se evalue en el entorno donde se define +consiste en pasar las variables de ese entorno que necesite en los argumentos de +entrada, casi siempre como argumentos por defecto.
+En el ejemplo anterior sería:
+ i = 1
+ add_one = lambda x, i=i: x + i
+que equivaldrá a
+ add_one = lambda x, i=1: x + i
+En este caso i se toma de los argumentos de la función, y tendrá por defecto
+el valor de i en el momento de la definición de la función lambda.
No es perfecto, pero es lo mejor que tenemos. Lo recomendable es evitar las +funciones lambda complejas si no queremos llevarnos algunas sorpresas.
+
+
+
+ +
-
+
-
+
Los valores de las listas son las opciones 3, 3 y 4, respectivamente. ↩
+
+
+
+
+
+ Descubriendo la programación funcional – Scala con David Vaquero
+República Web 09 01 2021
+Para el quinto episodio sobre la serie de programación funcional, Andros Fenollosa presenta junto al compañero David Vaquero el lenguaje Scala, otro gran lenguaje que también hace uso de la máquina virtual de Java y es multiparadigma. Esto es una las diferencias con los otros lenguajes funcionales que se han tratado en esta serie. Scala es un lenguaje diseñado por Martin Odersky y que trae juntos dos paradigmas: la orientación a objetos y la programación funcional.
+ + + +Entre las cuestiones discutidas en el episodio:
+ + + +- ¿Qué pasó por tu cabeza para meterte en la programación funcional?
- Dime algunas características que te rompieron la cabeza y te enamoraron.
- ¿Qué es Scala?
- ¿Cuál es su origen?
- ¿Qué lo hace especial respecto a Clojure?
- ¿Quién lo usa? ¿Para quién está orientado?
- ¿Cuáles son tus frameworks favoritos?
- Hablemos sobre el Front-End. ¿Existe implementación?
- ¿Cuál crees que es el futuro del ecosistema?
- ¿Existe una comunidad?
- Recursos y consejos para grumetes.
- Anécdotas, ¿qué es lo peor y lo mejor que te has encontrado?
No te pierdas los otros episodios de la serie sobre programación funcional sobre Clojure, Elixir, Haskell y Elm.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ GitHub Commit Bot to Stack Your Contributions Graph
+blog.karenying.com 04 01 2021
+
+ 
+
+
+ The Hero
+MonkeyUser 04 01 2021
+
+
+ 2020 Year in Review
+Haki Benita 03 01 2021
+What I've been up to in 2020...
+
+
+ How to open a file in Emacs
+Murilo Pereira 03 01 2021
+
+
+ Re-solutions
+Manuel Uberti 03 01 2021
+I’ve been studying philosophy at Ca’ Foscari for about a year and half now, +devoting most of my spare time to wonderful and wonderfully difficult books, and +enjoying every part of this journey. There is still a lot of ground to cover +because I see many gaps to fill and thoughts to process, but there is one thing +that I am sure of: it’s going to be the journey of a lifetime.
+ +I’ve not been so deeply fascinated and involved with something in a long while. +Ask my wife and she is going to tell you that perhaps my love for cinema can +match this passion for philosophy. I could agree, but cinema has not really been +on my side lately1. Beside few exceptions2, 2020 will not be remembered for the +films or the directors that inspired me to write.
+ +The last days of 2020 were dedicated to planning new year’s resolutions. To be +perfectly honest, I am not a great fan of new year’s resolutions. Most of the +time I forget about them in a couple of months. To circumvent my poor will, +I decided to keep the resolutions simple, small, and practical. This is what +I wrote down on my BuJo:
+ +-
+
- More books and less films +
- More philosophy and less fiction +
- Running +
The first two are easy to adopt side by side. I watched way too many forgettable +films last year, leaving the couch with the horrible feeling of time wasted. +I do not want to repeat that. If there isn’t a film to watch, I want to turn off +the TV, forget about my Blu-ray collection, and grab the book next to me.
+ +As for the kind of book to pick up, I want to avoid contemporary fiction. There +is nothing wrong with contemporary fiction, of course, but most of the +contemporary books I read in 2020 proved to be little more than decent +entertainment. There is so much to read, and it’s not just philosophy. I want +more classics on my bedside table, and I want to read more from authors I love. +Consider it a sabbatical. I intend to come back to contemporary fiction next +year.
+ +Finally, running. Let’s just say I stopped for no good reason and I am waiting +for my contact lens to start again. As simple as this resolution looks, +it’s also the most necessary one. Between work and studies the time I spend at +my desk has become unhealthy, and I know how fresh air and exercise make me +feel.
+ +For all the good things in this planning, I see a couple of drawbacks here. If I +manage to stick to these resolutions, computing is going to play a different +role in my life. I will still be in front of my Emacs five days a week, but +that’s about it. Whereas this means less tinkering and less githubbing, it also +means less writing for my blogs. Nevertheless, for the sake of my priorities, +I am willing to sacrifice writing just as I am willing to put cinema aside.
+ +Happy new year.
+ +Footnotes
+ +
+
+
+ -
+
-
+
The small number of articles published last year on my other blog, Films in +Words, is telling. ↩
+
+ -
+
See Films in Words. ↩
+
+
+
+ Re-solutions
+Manuel Uberti 03 01 2021
+I’ve been studying philosophy at Ca’ Foscari for about a year and half now, +devoting most of my spare time to wonderful and wonderfully difficult books, and +enjoying every part of this journey. There is still a lot of ground to cover +because I see many gaps to fill and thoughts to process, but there is one thing +that I am sure of: it’s going to be the journey of a lifetime.
+ +I’ve not been so deeply fascinated and involved with something in a long while. +Ask my wife and she is going to tell you that perhaps my love for cinema can +match this passion for philosophy. I could agree, but cinema has not really been +on my side lately1. Beside few exceptions2, 2020 will not be remembered for the +films or the directors that inspired me to write.
+ +The last days of 2020 were dedicated to planning new year’s resolutions. To be +perfectly honest, I am not a great fan of new year’s resolutions. Most of the +time I forget about them in a couple of months. To circumvent my poor will, +I decided to keep the resolutions simple, small, and practical. This is what +I wrote down on my BuJo:
+ +-
+
- More books and less films +
- More philosophy and less fiction +
- Running +
The first two are easy to adopt side by side. I watched way too many forgettable +films last year, leaving the couch with the horrible feeling of time wasted. +I do not want to repeat that. If there isn’t a film to watch, I want to turn off +the TV, forget about my Blu-ray collection, and grab the book next to me.
+ +As for the kind of book to pick up, I want to avoid contemporary fiction. There +is nothing wrong with contemporary fiction, of course, but most of the +contemporary books I read in 2020 proved to be little more than decent +entertainment. There is so much to read, and it’s not just philosophy. I want +more classics on my bedside table, and I want to read more from authors I love. +Consider it a sabbatical. I intend to come back to contemporary fiction next +year.
+ +Finally, running. Let’s just say I stopped for no good reason and I am waiting +for my contact lens to start again. As simple as this resolution looks, +it’s also the most necessary one. Between work and studies the time I spend at +my desk has become unhealthy, and I know how fresh air and exercise make me +feel.
+ +For all the good things in this planning, I see a couple of drawbacks here. If I +manage to stick to these resolutions, computing is going to play a different +role in my life. I will still be in front of my Emacs five days a week, but +that’s about it. Whereas this means less tinkering and less githubbing, it also +means less writing for my blogs. Nevertheless, for the sake of my priorities, +I am willing to sacrifice writing just as I am willing to put cinema aside.
+ +Happy new year.
+ +Footnotes
+ +
+
+
+ -
+
-
+
The small number of articles published last year on my other blog, Films in +Words, is telling. ↩
+
+ -
+
See Films in Words. ↩
+
+
+
+ 2020 Blogging Recap
+blog.karenying.com 01 01 2021
+
+
+ I Tracked My Mood Every Day of 2020
+blog.karenying.com 31 12 2020
+
+
+
+
+ Descubriendo la programación funcional – Elm con David Hernández
+República Web 27 12 2020
+Cuarto episodio de la serie especial sobre programación funcional dirigida por Andros Fenollosa. En esta ocasión se dedica al lenguaje Elm, algo particular debido a que ha sido diseñado para funcionar solo en el navegador web. Entre otras características podemos destacar que es declarativo, está influenciado por Haskell y diseñado para obtener robustez, usabilidad y rendimiento. Este lenguaje funcional hizo su aparición en el año 2012 gracias a Evan Czaplicki, creador de Elm.
+ + + +Para este episodio sobre Elm, Andros cuenta con la compañía de David Hernandez, un profesional con más de 10 años programando para empresas de servicios y productos. Aunque principalmente ha estado con PHP, también ha podido tocar Javascript, Node, Python, Java y Elm, lenguaje que le ha traído a nuestro podcast. Sus roles han sido diversos: CTO, development manager y tech lead entre otros.
+ + + +Entre las cuestiones discutidas en el episodio:
+ + + +-
+
- ¿Cómo te metiste a la programación funcional? +
- Origen y características de Elm +
- Beneficios y diferencias de Elm +
- Desventajas de Elm +
- Frontend con Elm +
- Futuro, comunidad y recursos +
No te pierdas los otros episodios de la serie sobre programación funcional sobre Clojure, Elixir y Haskell.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Blogmas 2020
+blog.karenying.com 25 12 2020
+
+
+ Embarking in a new affair with completions
+Manuel Uberti 25 12 2020
+What a year this 2020. Beside the pandemic changing our lives in unpredictable
+ways, from the perspective of my Emacs usage much was going on in my init.el
+until I felt that a temporary break was necessary.
Most of my tinkering concerned the minibuffer and its completion mechanisms. +I finished last year and started this one with Helm, but I am about to close +2020 with the built-in minibuffer completion and Embark providing candidates. +A solution that Protesilaos Stavrou explored and which has been really suiting +me.
+ +Before detailing how I adapted his approach to my preferences, though, let me +give you a bit of rationale. First, Helm rocks and it rocks hard. Its power is +evident after a couple of hours with it. I briefly used Icomplete tweaked to +display its results vertically, but I didn’t find it responsive enough to stick +with it. Then I found out about Selectrum, which fixed the responsiveness but +eventually was not adding a significant difference compared to Helm. True, +Selectrum has a simpler codebase, but were I only to look at my daily +interactions with Emacs, only the user interface can tell Helm and Selectrum +apart.
+ +Protesilaos took a different path. He wants to understand the code in front of +him, so the less changes the better. In this regard Helm, Selectrum, and even +Icomplete add a layer of indirection between him and the minibuffer. He is right +in this. The minibuffer is more capable than the plethora of completion +frameworks may suggest, and one can leverage its strength without forcing it to +behave in a totally new way. Protesilaos’ reasoning got me thinking. Once again, +am I looking for a solution from the outside before having really understood +what lies underneath my beloved text editor?
+ +Following Protesilaos’ steps, I set up the minibuffer to rely only on orderless
+and Embark, with Consult chiming in for a some of operations like better history
+in shell-mode and an improved apropos. What I added to Protesilaos’ code is the
+only thing that I felt was missing: a command to search for the symbol at point
+in my project, with the results displayed in an embark-live-occur window in
+order to quickly jump to a specific entry. Over at the Consult’s GitHub there
+are talks about a consult-rg utility which would serves this purpose, and there
+has been suggestions of using project-find-regexp as well.
(defun mu-project-find-refs ()
+ "Use `project-find-regexp' to search for thing at point."
+ (interactive)
+ (if-let (tap (thing-at-point 'symbol))
+ (project-find-regexp tap)
+ (message "Nothing at point to search for")))
+Easy enough to understand. However, if you, like me, set up Embark like
+Protesilaos does you’ll notice that this command doesn’t show any candidate
+unless you type something at the Jump to definition prompt. The candidates are
+there already, though, so I have to avoid waiting for an input and display the
+candidate list immediately.
The solution is straightforward: just remove embark-live-occur-after-input from
+minibuffer-setup-hook and use embark-live-occur-after-delay instead. I added a
+:before advice on mu-project-find-refs for this. The beauty of this advice is
+that it works elsewhere as well. For instance, I have been using it for
+consult-flymake and flyspell-correct-at-point too.
Note that this advice requires a little change to the original
+minibuffer-setup-hook I have lifted from Protesilaos. Instead of adding
+embark-live-occur-after-input to it I am using this to ensure only
+embark-live-occur-after-input is present.
(defun mu-embark-live-occur-after-input ()
+ "Ensure only `embark-live-occur-after-input' is active."
+ (remove-hook 'minibuffer-setup-hook #'embark-live-occur-after-delay)
+ (add-hook 'minibuffer-setup-hook #'embark-live-occur-after-input))
+Without a dedicated completion framework the minibuffer may feel rather basic at
+first, but do not let it deceive you with its frugality. Like project.el, all it
+needs is love.
+
+ Embarking in a new affair with completions
+Manuel Uberti 25 12 2020
+What a year this 2020. Beside the pandemic changing our lives in unpredictable
+ways, from the perspective of my Emacs usage much was going on in my init.el
+until I felt that a temporary break was necessary.
Most of my tinkering concerned the minibuffer and its completion mechanisms. +I finished last year and started this one with Helm, but I am about to close +2020 with the built-in minibuffer completion and Embark providing candidates. +A solution that Protesilaos Stavrou explored and which has been really suiting +me.
+ +Before detailing how I adapted his approach to my preferences, though, let me +give you a bit of rationale. First, Helm rocks and it rocks hard. Its power is +evident after a couple of hours with it. I briefly used Icomplete tweaked to +display its results vertically, but I didn’t find it responsive enough to stick +with it. Then I found out about Selectrum, which fixed the responsiveness but +eventually was not adding a significant difference compared to Helm. True, +Selectrum has a simpler codebase, but were I only to look at my daily +interactions with Emacs, only the user interface can tell Helm and Selectrum +apart.
+ +Protesilaos took a different path. He wants to understand the code in front of +him, so the less changes the better. In this regard Helm, Selectrum, and even +Icomplete add a layer of indirection between him and the minibuffer. He is right +in this. The minibuffer is more capable than the plethora of completion +frameworks may suggest, and one can leverage its strength without forcing it to +behave in a totally new way. Protesilaos’ reasoning got me thinking. Once again, +am I looking for a solution from the outside before having really understood +what lies underneath my beloved text editor?
+ +Following Protesilaos’ steps, I set up the minibuffer to rely only on orderless
+and Embark, with Consult chiming in for a some of operations like better history
+in shell-mode and an improved apropos. What I added to Protesilaos’ code is the
+only thing that I felt was missing: a command to search for the symbol at point
+in my project, with the results displayed in an embark-live-occur window in
+order to quickly jump to a specific entry. Over at the Consult’s GitHub there
+are talks about a consult-rg utility which would serves this purpose, and there
+has been suggestions of using project-find-regexp as well.
(defun mu-project-find-refs ()
+ "Use `project-find-regexp' to search for thing at point."
+ (interactive)
+ (if-let (tap (thing-at-point 'symbol))
+ (project-find-regexp tap)
+ (message "Nothing at point to search for")))
+Easy enough to understand. However, if you, like me, set up Embark like
+Protesilaos does you’ll notice that this command doesn’t show any candidate
+unless you type something at the Jump to definition prompt. The candidates are
+there already, though, so I have to avoid waiting for an input and display the
+candidate list immediately.
The solution is straightforward: just remove embark-live-occur-after-input from
+minibuffer-setup-hook and use embark-live-occur-after-delay instead. I added a
+:before advice on mu-project-find-refs for this. The beauty of this advice is
+that it works elsewhere as well. For instance, I have been using it for
+consult-flymake and flyspell-correct-at-point too.
Note that this advice requires a little change to the original
+minibuffer-setup-hook I have lifted from Protesilaos. Instead of adding
+embark-live-occur-after-input to it I am using this to ensure only
+embark-live-occur-after-input is present.
(defun mu-embark-live-occur-after-input ()
+ "Ensure only `embark-live-occur-after-input' is active."
+ (remove-hook 'minibuffer-setup-hook #'embark-live-occur-after-delay)
+ (add-hook 'minibuffer-setup-hook #'embark-live-occur-after-input))
+Without a dedicated completion framework the minibuffer may feel rather basic at
+first, but do not let it deceive you with its frugality. Like project.el, all it
+needs is love.
+ 
+
+
+ Controlando el tiempo de arranque con systemd-analyze
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 24 12 2020
+Seguro que alguna vez nos hemos preguntado por que desde hace unos días nuestra distribución de Linux tarda mas de lo habitual en arrancar, o sencillamente nos hemos planteado hacer un arranque del sistema en tiempo record.
+Pues ahora os vamos a presentar una utilidad que nos lo va a poner mas facil que nunca!
+Con systemd-analyze vamos a poder identificar a los culpables de esos inicios lentos o que nos causan problemas.
+Si lo invocamos sin parametros con systemd-analyze obtendremos la siguiente salida:
No es muy impresionante, pero con esta vista general del firmware, gestor de arranque, kernel y espacio de usuario ya empezamos a tener una noción de donde se nos vá la mayor parte del tiempo.
+Si queremos mas detalles y ver los servicios uno a uno, vamos a utilizar el parametro blame: systemd-analyze blame
Esto ya es otra cosa y ya podemos señalar con el dedo a los culpables de nuestros lentos inicios del equipo. Ahora solo quedaría desactivar los servicios que nos estén causando problemas y a volar.
+Pero, y si a mi no me gusta todo este ladrillo de texto y se me hace de noche intentando descifrar numeros y servicios?..
+No digas más, el parametro plot viene al rescate. Si usamos este parametro y además redirigimos la salida a una imagen tal que así: systemd-analyze plot > analisisgrafico.svg
Obtendremos una gŕafica como esta que nos facilitiará aún mas si cabe el diagnostico e identificación de procesos lentos.
+Espero que el conocimiento de esta útil herramienta os sea de ayuda en vuestros diagnosticos!
+
+
+
+
+ 8 predicciones sobre cómo la tecnología continuará cambiando nuestras vidas en el 2021
+República Web 23 12 2020
+Episodio dedicado a comentar el estupendo artículo de Werner Vogels, CTO y vicepresidente de Amazon, titulado 8 predicciones sobre como la tecnología continuará cambiando nuestras vidas en el 2021. Este artículo publicado en su blog personal All Things Distributed, es un análisis de gran interés para comprender los cambios que la tecnología producirá no sólo en el 2021, sino también la próxima década.
+ + + +Werner Vogels demuestra un conocimiento global del impacto de la tecnología y cómo las tecnologías de Amazon Web Services están a la vanguardia de muchas tendencias tecnológicas. Otro punto muy destacable es la absoluta confianza en la capacidad de la tecnología para mejorar nuestras vidas. Al contrario que la visión pesimista de otras personas con respecto a la tecnología, Werner desborda optimismo y un total convencimiento de que el acceso asequible a la tecnología ayudará a que muchas regiones del planeta mejoren su calidad de vida.
+ + + +Las 8 predicciones de Werner Vogels para el 2021 y más adelante son:
+ + + +-
+
- Predicción 1. La nube estará en todas partes. +
- Predicción 2. La internet del aprendizaje automático +
- Predicción 3: En el 2021 imágenes, video y audio hablarán más que las palabras. +
- Predicción 4: La tecnología transformará nuestros mundos físicos tanto como los mundos digitales. +
- Predicción 5. El aprendizaje en remoto se gana su sitio en la educación. +
- Predicción 6. Los negocios pequeños se lanzarán a la nube y Sudeste asiático y el áfrica subsahariana liderarán el camino. +
- Predicción 7. La computación cuántica comenzará a florecer. +
- Predicción 8. La frontera final… +
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ 2020 In Review
+Josh Comeau's blog 23 12 2020
+
+ 
+
+
+ Tutorial para cancelación de ruido de fondo en Linux
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 23 12 2020
+Seguramente os habréis encontrado con que en Linux hay bastantes problemas con el tema del ruido de fondo en las grabaciones con micrófono. Y en las ultimas versiones se ha agrabado el inconveniente, hasta ahora!
+Con este sencillo tutorial vamos a crear una nueva entrada de audio filtrada para deshacernos del molesto ruido de fondo del micriófono. Estas indicaciones funcionan para los problemas con Ubuntu, Linux Mint, Debian, etc.
++
Abriremos una ventana de terminal, y editaremos el fichero /etc/pulse/default.pa para añadir el filtro de cancelación de ruido de pulseaudio al final del fichero donde veremos que se cargan otros módulos similares.
+Abriremos un terminal y escribimos:
+[code]sudo nano /etc/pulse/default.pa[/code]+
Nuestro fichero actual, al final del mimsmo, debería contener algo así, y es ahí donde debemos añadir el filtro de cancelación de ruido:
+[code]### Modules to allow autoloading of filters (such as echo cancellation)+
### on demand. module-filter-heuristics tries to determine what filters
### make sense, and module-filter-apply does the heavy-lifting of
### loading modules and rerouting streams.
load-module module-filter-heuristics
load-module module-filter-apply[/code]
Añadimos el filtro de cancelación de ruido "load-module module-echo-cancel" al final de esas opciones, quedando algo así:
+[code]### Modules to allow autoloading of filters (such as echo cancellation)+
### on demand. module-filter-heuristics tries to determine what filters
### make sense, and module-filter-apply does the heavy-lifting of
### loading modules and rerouting streams.
load-module module-filter-heuristics
load-module module-filter-apply
load-module module-echo-cancel[/code]
Una vez añadido, reiniciaremos el servicio de audio con el siguiente comando (Ojo, si conectamos un nuevo micrófono, posiblemente debamos recargar pulseaudio de nuevo este comando):
+[code]pulseaudio -k[/code]+
Veremos que nos han aparecido nuevos dispositivos de control en los ajustes de sonido de nuestra distribución, seleccionaremos la nueva entrada de micrófono con cancelación de audio activa.
+Espero que noteis una mejoría en vuestras grabaciones :)
+
+ 
+
+
+ Guia de instalación drivers propietarios Nvidia en Fedora
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 23 12 2020
+Seguramente mas de uno habréis querido instalar Fedora en vuestros equipos con potentes tarjetas graficas de Nvidia solo para terminar dejandolo por imposible por la cantidad de trabas y problemas que nos han puesto los de nvidia con su limitado soporte. Pues vamos a acabar con esto de golpe con un tutorial que nos permitirá cambiar el driver de codigo abierto nouveau por el propietario de Nvidia.
+Bueno, vamos al lío. Preparaos por que vienen curvas :)
+**Este tutorial solo funciona con escritorio x11**
+
1.- Antes de empezar con la instalación de nuestros drivers NVIDIA, vamos a comprobar que nuestra tarjeta esta soportada.
+Para ello vamos a lanzar en nuestra terminal (Ctrl + ALT + T) el siguiente comando:
+[code]lspci |grep -E "VGA|3D"[/code]+
Nos tiene que aparecer algo como esto:
+[code]01:00.0 VGA compatible controller: NVIDIA Corporation TU106 [GeForce RTX 2060 Rev. A] (rev a1)[/code]+
Chequea el mejor driver de tu tarjeta grafica en este enlace: lista
+Si tienes activado UEFI Secure BOOT, hay que desactivarlo desde la BIOS.
+
2.- Instalar los drivers propietarios de NVIDIA y desactivar el driver nouveau.
Para descargar el paquete instalador de NVIDIA iremos al siguiente enlace y buscamos la ultima versión del driver de nuestra tarjeta.
+Una vez hayamos buscado y descargado nuestro driver vamos a hacer ejecutable el .run que se nos ha descargado. Para ello ejecutamos en la terminal el siguiente comando:
+[code]chmod +x /Descargas/NVIDIA-Linux-*.run[/code]+
+
- Cambiamos al usuario root con:
++su -## O ##sudo -i
- Asegurate de que tu sistema esta actualizado y estas con el ultimo kernel.
[code]dnf update[/code]+
- Después de actualizar reinicia el equipo e inicia con el ultimo kernel.
reboot+
+
- Instalamos las dependencias necesarias:
+dnf install kernel-devel kernel-headers gcc make dkms acpid libglvnd-glx libglvnd-opengl libglvnd-devel pkgconfig+
+
- Desactivamos nouveau. Podemos crear o editar etc/modprobe.d/blacklist.conf
+Añadimos ‘blacklist nouveau’
+[code]echo "blacklist nouveau" >> /etc/modprobe.d/blacklist.conf[/code]+
-Editamos etc/default/grub
Añadimos ‘rd.driver.blacklist=nouveau’ al final de ‘GRUB_CMDLINE_LINUX=”…”‘.
++## Fedora 34 BTRFS ##GRUB_CMDLINE_LINUX="rhgb quiet rd.driver.blacklist=nouveau"## O CON LVM ##GRUB_CMDLINE_LINUX="rd.lvm.lv=fedora/swap rd.lvm.lv=fedora/root rhgb quiet rd.driver.blacklist=nouveau"
- Actualizamos grub2 conf
+## BIOS y UEFI ##grub2-mkconfig -o /boot/grub2/grub.cfg
+
- Borramos xorg-x11-drv-nouveau
+[code]dnf remove xorg-x11-drv-nouveau[/code]+
- Generamos initramfs
+## Copia de seguridad antigua imagen nouveau ##mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r)-nouveau.img"## Crear nueva imagen initramfs ##dracut /boot/initramfs-$(uname -r).img $(uname -r)"
- Reiniciar en runlevel 3
++systemctl set-default multi-user.targetreboot
- Ahora vamos a instalar los drivers propietarios en modo texto. Nos loguearemos y volvemos a entrar como usuario root de la siguiente manera:
++su -## O ##sudo -i
-Ejecutamos el instalador del driver que en este caso sera un .run de la siguiente manera:
+./NVIDIA-Linux-*.run## O ruta completa ##/home/usuario/Descargas/NVIDIA-Linux-x86_64-xxx.xxx.xx.run
- Registar los módulos fuente del núcleo con DKMS:
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
- Bibliotecas de compatibilidad de 32 bits:
+
- Instalando controladores y construyendo el módulo del kernel:
+
+
- Instalador automático de configuración y copia de seguridad de Xorg:
- Instalación de drivers completada:
+
- Ya está todo hecho y reiniciamos de nuevo en runlevel5
++systemctl set-default graphical.targetreboot
+
- Soporte VDPAU/VAAPI
+Habilitar el soporte de aceleración de vídeo (Nota: necesitas Geforce 8 o posterior).
+[code]sudo dnf install vdpauinfo libva-vdpau-driver libva-utils[/code]+
- Para poder abrir nvidia-settings, tienes que hacer lo siguiente:
ALT + F2 y escribir nvidia-settings
+
3.- Capturas de pantalla usando nvidia settings con kernel 5.11.16
+
+
** El driver de nvidia en el kernel 5.11.17 no funciona. Una vez pasas al kernel 5.11.18 vuelve a funcionar sin problemas, por ello mismo hemos bloqueado que suba o baje automáticamente de kernel. No obstante si quieres eliminar el bloqueo y poder escalar de kernel, te dejo el comando para hacerlo.**
[code]sudo dnf versionlock delete kernel-x.x.xx-xx.xxx[/code]+
+
+ SciCloj #18: Introducing Skija
+tonsky.me 23 12 2020
+
+
+
+
+ Cómo ha afectado la Covid-19 en la inversión publicitaria
+No sin mis cookies 22 12 2020
+La crisis derivada de la Covid-19 ha marcado un precedente en la economía global y un punto de inflexión en el ecosistema digital, con el consiguiente impacto en la inversión publicitaria como consecuencia del cambio en la forma en la que compramos, consumimos medios y trabajamos.
+The post Cómo ha afectado la Covid-19 en la inversión publicitaria appeared first on No sin mis cookies.
+ +
+
+
+
+ Red Hat mata CentOS y Kubernetes hace obsoleto a Docker
+República Web 21 12 2020
+Primer episodio de Informe Nube, una nueva serie dedicada a la actualidad de las tecnologías cloud y contenedores. David Vaquero y Antony Göetzschel repasan diferentes noticias relacionadas con la nube, ofreciendo su particular análisis. Este primer episodio de la serie, trae muchas cuestiones de gran interés para los profesionales del cloud.
+ + + +Para empezar la serie David y Antony comienzan con una de las noticias más controvertidas de los últimos meses: el cambio de dirección en CentOS Linux, la distribución surgida de un fork de Red Hat Entreprise Linux, hacia CentOS Stream. Este cambio deja en el aire muchas instalaciones de CentOS. Para entender este movimiento es importante comprender el flujo del desarrollo de este sistema y también los intereses de IBM como propietaria de Red Hat. Por supuesto, la comunidad de software libre no ha dudado en buscar alternativas.
+ + + +En la segunda parte del episodio se dedica a hablar sobre como Kubernetes no requiere Docker como entorno de ejecución. Sin duda, un movimiento que muestra la diversidad y velocidad de los cambios que existen en estas tecnologías.
+ + + +Otro tema de conversación en el episodio consiste en la idoneidad de presentarse a ofertas laborales, aunque no tengas todos los conocimientos que exigen.
+ + + +Como es un episodio de arranque, David y Antony continúan con más temas. Uno viene a raíz de un vídeo de Pelado Nerd. ¿Cuál es la mejor solución para un cluster de Kubernetes? y el último bloque se dedica a comentar que Rancher presenta Harvester una solución HCI (Hyper-Converged infrastructure).
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ Descubriendo la programación funcional – Haskell con Héctor Navarro
+República Web 18 12 2020
+Tercera entrega de la serie especial dedicada a la programación funcional presentada por Andros Fenollosa. En este tercer episodio le toca el turno a Haskell de la mano de Héctor Navarro, profesor e investigador en el área de Algoritmos y Lenguajes de Programación. Héctor Navarro actualmente trabaja como Ingeniero de Software en Amazon.com. Desde el año 2000 hasta 2018 ha desempeñado su labor de investigador y profesor en la Universidad Central de Venezuela. A pesar de usar primordialmente Java en trabajo diario, sigue siendo un gran entusiasta de Haskell y de la programación funcional.
+ + + +Haskell es un lenguaje de programación funcionalmente puro, con tipado estático y evaluación perezosa. Su nombre fue otorgado por Haskell Curry, matemático y lógico estadounidense que aportó el cálculo Lambda (un sistema para definir funciones y recursión creado por el matemático y lógico Alonzo Church), siendo este muy influyente dentro del lenguaje. Con Héctor Navarro tenemos oportunidad de tratar interesantes cuestiones del lenguaje:
+ + + +- ¿Qué pasó por tu cabeza para meterte en la programación funcional?
- Dime algunas características que te rompieron la cabeza y te enamoraron.
- ¿Qué es Haskell y cuál es su orgien?
- ¿Qué lo hace especial respecto a otros lenguajes?
- ¿Quién usa Haskell y para quién está orientado?
- ¿Qué son las monadas?
- ¿Cuáles son tus frameworks favoritos?
- Hablemos sobre el Front-End. ¿Existe implementación? ¿Tal vez Elm?
- ¿Cuál crees que es el futuro del ecosistema?
- ¿Existe una comunidad?
- Recursos y consejos para grumetes.
En esta interesante conversación Héctor Navarro nos cuenta detalles relevantes sobre Haskell, aplicaciones, usos, herramientas y recursos.
+ + + +No olvidéis escuchar y visitar los enlaces de los dos primeros episodios de la serie sobre programación funcional:
+ + + +-
+
- Descubriendo la programación funcional – Elixir con Erick Navarro +
- Descubriendo la programación funcional – Clojure con Vachi + +
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ Guía para comprar enlaces en blogs y periódicos
+No sin mis cookies 15 12 2020
+Aprende a invertir de forma inteligente en la compra de enlaces para cumplir los objetivos de tu negocio y sin tirar el dinero.
+The post Guía para comprar enlaces en blogs y periódicos appeared first on No sin mis cookies.
+ +
+
+ Another Common Lisp app in production
+Lisp journey 14 12 2020
+A quick post to celebrate the birth of another Common Lisp application +running in production©. This time, it is not open source, but I can describe it.
+ +It is used by bookshops in France and Belgium to upload there catalogue to online +platforms. And no, they don’t know, and don’t need to know, the +language it is implemented in!
+ +It is a simple application that reads data from an existing DB, builds +a text file with special rules, sends the file to an FTP server, and +does it every day. I used cl-dbi with raw SQL queries, +cl-ftp (does its job perfectly), and a CRON job. I +built a binary that I sent to my server. It is a stand-alone +application that reads a DB that is created by a bigger Python/Django +web app (that I also develop). I didn’t want to make this one more +bloated, so given the goals are complementary but orthogonal, I went +with a stand-alone tool.
+ +That’s it. One more!
+ +Another tool I am running connects to a SOAP service, shows data on a website (with Sentry configured in production), sells products with Stripe and sends emails with Sendgrid. And I (generally) update it while it runs by connecting to the Lisp REPL. Just throwing out buzzwords to you.
+ +While I’m at it, let me stress one point, to answer in advance a kind +of feedback I already had: no, the resulting application doesn’t use +any Lisp superpower and yes, I could have written it in Python. It +turns out Lisp is as suited as Python for this task (or then it is +more suited, since it is faster), the point is I benefited from Lisp’s +superpowers during development (by using the superior REPL, being able +to build a binary and all that). In conclusion: there are tons of +places where Lisp can be used for professional needs out there.
+ +Oh. In doing it, I built those two utilities:
+ +-
+
- progressons, a progress bar that holds on one line and works on the terminal as well as on Slime. It works for me©. My next goal is to make it output a prettier bar with unicode bars. +
- termp, a trivial utility that checks if we are on a real or on a dumb terminal (by checking the
TERMenvironment variable). So you canquitorerrorout.
+
Two more Lisp repositories on Github !
+ +
+
+ Pro mailing list: on Common Lisp and parallel GC
+Lisp journey 14 12 2020
+I recently enjoyed this discussion on the pro mailing list. It started with a call of recommendations on music software, and the discussion evolved in discussing parallel garbage collection. By the way, can you site an implementation that has parallel GC?
+ ++ +
Pascal Costanza:
+ +«When moving our elPrep software away from Common Lisp, we evaluated C++, Go and Java as potential candidates, and Go turned out to provide the best balance between performance and memory use. We are still using Common Lisp for prototyping, and then translate to Go. These two languages are actually much more similar than it appears at first. […]»
+ +«This was primarily for the lack of good parallel, concurrent garbage collectors in Common Lisp implementations. The CL version of elPrep was actually still a tad faster than any of the C++, Go, or Java versions, but we had to work hard to avoid long GC pauses. elPrep allocates a lot of memory, and the pause time hurts a lot. We solved this by, basically, disabling the garbage collector, and reusing memory manually as much as possible, which turned the program into almost a manually memory-managed affair.»
+ +«Manual memory management became a huge burden because we wanted to add more and more components to the software, and then it becomes almost impossible to predict object lifetimes.»
+ +«We evaluated Go and Java for their concurrent, parallel GCs, and C++ for its reference counting. Interestingly, reference counting is often described as more efficient than GC, but in our case that’s not true: Because there is a huge object graph at some stage that needs to be deallocated, reference counting incurs more or less the same pause that a non-concurrent GC does. That’s why we don’t expect Rust to fare better here either.»
+ +«Again, we’re still prototyping in Common Lisp, which is a huge win, because this makes us much more productive.»
+ +«In my opinion, prototyping in Common Lisp, and then translating to a +different programming language for creating the final product, is a +perfectly valid professional use of Common Lisp. It’s useful to know +which programming languages may be good targets for such an approach. This is, of course, not ideal, because this can easily be +misunderstood as a statement that Common Lisp is not fit for +purpose. However, I don’t see it that way, and you cannot control +people’s perceptions. In our particular case, our manager is on board with this approach, and this allows us to pay for regular licenses for LispWorks. The +approach works really well for us.»
+ +Didier Verna:
+ +«I’d be curious to know if there are particularities in CL itself that make this difficult, or if it’s simply because there’s no manpower to improve the GCs we have currently.»
+ +Stelian Ionescu:
+ +«It’s strictly a lack of manpower. Most CL implementations have GCs that were state-of-the-art 25 years ago: they’re either mark-and-sweep or copying & generational, and have to perform all collection while application threads are paused (i.e. stop-the-world), hence the collection pauses that are proportional to the heap size.»
+ +«The newer GCs of Go and the JVM (ZGC and Shenandoah) are not generational and employ techniques such as pointer coloring and store/load barriers by instrumenting all object read/write operations instead of using virtual memory protection (which tends to have a non-indifferent performance penalty), and because they rely heavily on atomic operations to maintain heap consistency the stop-the-world phase is much shorter and only required to update the internal GC metadata. +The result is that instead of 99th percentile pauses of 10+ seconds that we see with QPX or other allocation-heavy applications, these newer GCs show 99th percentile pauses of < 10ms, and perhaps medians going from ~500ms to 2ms (YMMV).»
+ +«Here’s a pretty good description of the difference between the two new JVM collectors and how they compare to the older ones: https://www.youtube.com/watch?v=WU_mqNBEacw.»
+ +Martin Cracauer:
+ +«No, it’s as possible as in other languages. Some people don’t want to pay the overall performance penalty for concurrent GC (as in total CPU time/energy spent for any given piece of work).»
+ +«This particularly applies to applications that are query-based, and hence want to be as fast as possible in the non-GC part, and can GC between queries. ITA’s QPX is an example (although they do desire concurrent GC for better monitoring in the production environment).»
+ +«Parallel GC is no problem and implemented.»
+ +Pascal Costanza:
+ +«Which CL implementations have a parallel GC?»
+ +Jeff Caldwell:
+ +«From Franz’s doc on Allegro CL: https://franz.com/support/documentation/10.0/doc/gc.htm#multi-threading-2»
+ +Martin Cracauer:
+ +«Clasp (via Boehm GC and MPS).»
+ +«I thought SBCL was there, but I just checked, not yet. I think Google +is pushing for a parallel GC instead, because of response times to +their production monitoring.»
+ +«Another untapped source of performance is userfaultfd(2) in the Linux kernel. It allows those GCs that implement a write barrier using page protections SIGSEGV to use the faster userfaultfd interface instead (as opposed to those using a bitmap). This won’t help concurrent GC, but parallel GC would benefit even more than single-thread GC because it uses faster system calls. Proof of concept is here: https://www.cons.org/cracauer/cracauer-userfaultfd.html»
+ +and:
+ +++ +Don’t the latest incarnations of ECL use the Bohem GC?
+
Daniel Kochmański:
+ +«They do, we plan to resurrect the homegrown gc as an alternative though.»
+ +
+
+ Refreshing Server-Side Props
+Josh Comeau's blog 14 12 2020
+
+
+ GitHub Dark Mode is Too Dark
+blog.karenying.com 12 12 2020
+
+
+
+
+ Desarrollando aplicaciones móviles y PWA con Vue.js
+República Web 12 12 2020
+Para este episodio vuelve a acompañarnos en el podcast la diseñadora y desarrolladora web Valentina Rubane. Ella trabaja junto a Andros en Sapps, el estudio de desarrollo de aplicaciones móviles y PWA en Valencia. En este episodio hablamos de los motivos por los que Vue.js es la elección de Sapps para estudio para trabajar el desarrollo de sus aplicaciones.
+ + + +Valentina y Andros nos cuentan entre otras muchas cosas:
+ + + +- Evolución de Vue.js
- Novedades de Vue.
- Herramientas de desarrollo con Vue.js
- Vue.cli y trabajo con componentes y librerías CSS.
- Aprendizaje y metodologías de uso.
- Trabajos y experiencias con proyectos de clientes.
Sapps es el estudio surgido de Pixel Mouse y está especializados en desarrollo de aplicaciones web, móviles y también PWA. En la actualidad lo forma un grupo de varias personas con experiencia en las diferentes capas de un proyecto en internet.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+ 
+
+
+ Cypress React Testing, Accessibility Tooling, Offline Websites, and Chaos Engineering! 👱♀️ — Pony Foo Weekly
+Pony Foo Weekly 10 12 2020
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
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+
+ Hands-Free Coding
+Josh Comeau's blog 09 12 2020
+
+
+ Exhaustiveness Checking with Mypy
+Haki Benita 07 12 2020
+What if mypy could warn you about possible problems at "compile time"? In this article I share a little trick to get mypy to fail when a value in an enumeration type is left unhandled.
+
+
+
+
+ El futuro de la profesión de desarrollador web
+República Web 06 12 2020
+Se acerca el final de un año que ha dejado más claro que nunca lo difícil que resulta realizar predicciones. Todavía más en un sector tan endiablado como el desarrollo web. Por eso hemos pensado para este episodio del podcast, tratar más sobre direcciones y tendencias profesionales, en lugar de hacerlo más sobre ciertas tecnologías. Para ello planteamos un episodio con dos cuestiones de gran interés.
+ + + +¿Qué habilidades o competencias tendrán más valor en el futuro de la profesión de desarrollo web?
+ + + +En esta primera parte del episodio aportamos nuestra opinión, acerca de las competencias que tendrán más importancia en la profesión del desarrollo web. Entre varias cuestiones que aportamos:
+ + + +- Trabajo en equipo, distribuido y en remoto.
- Competencia en comunicación y habilidades que impliquen responder mejor y más rápido a las necesidades del cliente.
- Capacidad de adaptación, concentración y flexibilidad mental.
- Herramientas de UI/UX.
- Interactividad con servicios o APIs de terceros.
- Configuración de herramientas No Code para uso final.
- Abuso de la figura de los becarios.
- Arquitectura
- Integración de sistemas.
- Desarrollo de producto.
- Conservación/atracción de equipos y talento
¿Qué tecnologías consideráis que serán absolutamente necesarias en los próximos años?
+ + + +En este segundo apartado ya intentamos hablar más sobre tecnologías y herramientas que ayudarán al trabajo del desarrollo web. Entre varias hablamos de:
+ + + +- Frameworks front y back.
- Herramientas todo en uno para computación en la nube (AWS)
- Seguridad.
- Testing.
- CI / CD.
- Web Components.
- Swagger open api
- Entornos desacoplados
- JWT – OAUTH
- Linux
- Docker
- Notion
- Emacs
En este apartado también hablamos sobre cómo los frameworks y las librerías CSS han cubierto gran parte de las necesidades de maquetación y animación que muchos proyectos web requieren.
+ + + +Por último indicar que estaremos encantados de recibir vuestras aportaciones a esta cuestión del futuro del desarrollo web.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+
+
+ La memoria del dato
+Onda Hostil 05 12 2020
+
+
+
+
+ Descubriendo la programación funcional – Elixir con Erick Navarro
+República Web 05 12 2020
+Andros Fenollosa sigue con su serie especial sobre Programación Funcional con Elixir. Para ello cuenta esta vez desde Perú, con el compañero Erick Navarro, un experimentado programador en Python, JavaScript y por supuesto en Elixir.
+ + + +Elixir, un lenguaje de programación funcional, concurrente, de propósito general que se ejecuta sobre la máquina virtual de Erlang (BEAM). Al funcionar sobre Erlang comparte las mismas abstracciones para desarrollar aplicaciones distribuidas y tolerantes de fallos.
+ + + +Elixir destacado en el sector con empresas que han confiado es sus capacidades, como Pinterest o Discord. Su comunidad es tan grande que se realizan diferentes encuentros anuales e EEUU, Europa y Japón. Andros conversa con Erick sobre diferentes cuestiones:
+ + + +- Elixir, origen y diferencias con otros lenguajes.
- Usos y aplicaciones de Elixir.
- Frameworks de Elixir
- Uso en frontend.
- Comunidad y recursos.
- Futuro del lenguaje.
Este episodio es el segundo en una serie especial de Programación Funcional presentada por Andros Fenollosa. Escucha el primer episodio sobre Clojure.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Updated Debian 10: 10.7 released
+Debian News 05 12 2020
+buster). +This point release mainly adds corrections for security issues, +along with a few adjustments for serious problems. Security advisories +have already been published separately and are referenced where available. + +
+ 
+
+
+ Circle of AI Life
+MonkeyUser 04 12 2020
+
+
+ Fusionar commits
+Óscar Lijó 03 12 2020
+¿Por qué fusionar commits? Fusionar commits es una de las cosas mas chulas que podemos hacer, manipular la historia de nuestro proyecto hace que este sea mucho más legible y que podamos encontrar el cambio que queremos más rápido. A quien no le ha pasado que aunque estaba trabajando en una tarea, ha acabado subiendo…
+La entrada Fusionar commits aparece primero en Óscar Lijó.
+ +
+ 
+
+
+ Instapaper Weekly Sponsorship
+Instapaper 03 12 2020
+We are excited to announce that we are once again opening up sponsorship slots on the Instapaper Weekly email.
About Instapaper Weekly
Instapaper Weekly is an algorithmically-generated newsletter that goes out every Sunday. The email contains the most popular highlight created by all Instapaper users for the week and a list of the most popular articles saved to Instapaper for each day of the past week.
The Weekly is currently delivered to approximately 3 million Instapaper users. The open rate on the mailer is 7.7 percent, with an average click-to-open rate of 0.8% on advertisements.
Why Sponsorships?
By design, the Instapaper Weekly is a reflection of what our readers consider to be the most important and noteworthy topics for a given week. Sponsoring the Weekly places your content amongst the best content Instapaper has to offer and provides access to a large, engaged audience of tech-oriented and well-read professionals.
Sponsoring
As the Weekly compiles content our users found most compelling, we will be holding our sponsorship choices to the same standards of high quality. Your sponsored content should fit within our existing format for Instapaper Weekly and consist of a link, title, description, and thumbnail image. Ideally, the link would be something that our mobile-centric users can save to Instapaper for later reading.
We will run the sponsorship between the “Top Highlight” and “Most Popular” sections of the weekly email:
We are currently charging a flat rate of $2,500 for advertisements in the Instapaper Weekly, and offer one placement per week.
If you’re interested in sponsoring the Instapaper Weekly, please email us at sponsors@instapaper.com.
– Instapaper Team
+
+
+
+
+ Tres claves para hacer un currículum exitoso
+No sin mis cookies 03 12 2020
+Los tiempos han cambiado. El currículum es más que una carta de presentación. Es tu marca, tu identidad, la que te diferenciará respecto a tus competidores. Descubre cómo adaptarlo al mundo digital y enamora a tu futura empresa.
+The post Tres claves para hacer un currículum exitoso appeared first on No sin mis cookies.
+ +
+
+ November 2020 Monthly Update
+News on Clojurists Together 03 12 2020
+
+
+ Sick of the stupid jokes? Write your own arbitrary-precision JavaScript math library
+James Sinclair 30 11 2020
+
+
+ Sick of the stupid jokes? Write your own arbitrary-precision JavaScript math library
+Web Development - James Sinclair 30 11 2020
+
+
+ Q4 2020 Funding Announcement
+News on Clojurists Together 30 11 2020
+
+
+ Quarantine Day 259: Princeton CS Senior Takes the AP CS Exam
+blog.karenying.com 29 11 2020
+
+
+ Diferencias entre IaaS, CaaS, PaaS, FaaS y SaaS
+Óscar Lijó 28 11 2020
+Con la llegada de la nube hemos tenido que aprender una serie de términos que no estabamos acostumbrados a escuchar. Algunos de ellos son los que aparecen en el título de esta entrada. Aunque pueden parecer un trabalenguas son bastante sencillos de entender ya que todos hacen referencia a lo mismo, al nivel de gestión…
+La entrada Diferencias entre IaaS, CaaS, PaaS, FaaS y SaaS aparece primero en Óscar Lijó.
+ +
+
+
+
+ Descubriendo la programación funcional – Clojure con Vachi
+República Web 28 11 2020
+Este es el primer episodio de una serie especial del podcast dirigida a descubrir la programación funcional. Andros Fenollosa charla con diferentes invitados sobre el paradigma de la programación funcional, los lenguajes más destacables, herramientas y el cambio de mentalidad a la hora de afrontar este tipo de programación, especialmente si vienes de la programación orientada a objetos.
+ + + +Para este primer episodio Andros ha invitado a Vachi, un programador especializado en Clojure y actualmente trabajando en una fintech. Con Vachi habla sobre el lenguaje Clojure, sus características más destacables, principios de programación y lo que hace de Clojure un lenguaje tan atractivo para muchas empresas. También hablan de la comunidad de Clojure y recursos de interés para los que quieran comenzar con Clojure.
+ + + +Clojure es un lenguaje multiparadigma de propósito general creado por Rich Hickey como un dialecto de Lisp y orientado a trabajar con los datos a través de funciones. A diferencia de otros lenguajes como Python o C, Clojure se ejecuta sobre la JVM (Máquina virtual de Java).
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Tabla de códigos de estado HTTP
+Óscar Lijó 27 11 2020
+Una tabla de códigos de estado HTTP siempre hace falta, aqui tienes una bastante completa por si ese código no te suena 1×× Informativo Código Estado Descripción 100 Continue El servidor recibe la parte inicial de la solicitud, la da por buena y tiene intención de responder cuando la tenga toda 101 Switching Protocols El…
+La entrada Tabla de códigos de estado HTTP aparece primero en Óscar Lijó.
+ +
+ 
+
+
+ Welcome To Hell
+MonkeyUser 27 11 2020
+
+
+ The Ultimate Guide to Becoming a VSCode Girl
+blog.karenying.com 25 11 2020
+
+
+ Simple React Router Nav Bar
+blog.karenying.com 22 11 2020
+
+
+
+
+ Webflow, diseño web no code con Xavi Barrachina
+República Web 21 11 2020
+Los procesos creativos y el diseño web muy a menudo suelen enfrentarse a la barrera de la codificación y las limitaciones técnicas. Desde aquellos primeros sitios web de aspecto plano y poco atractivo, la tecnología del diseño web ha ido incorporando herramientas que ayuden a expresar de mejor manera la creatividad de los diseñadores. Aunque los creadores de sitios web puedan contar con infinidad de posibilidades para comunicar sus ideas, sigue existiendo esa barrera que impone la disciplina del código.
+ + + +¿Debes ser programador para realizar tu propia página web o vivir haciendo páginas web para los demás? Son muchas las herramientas que existen para facilitar la construcción visual de sitios web, pero muchas veces los inconvenientes de utilizar esas herramientas exceden con el tiempo a su conveniencia.
+ + + +Como ya hemos comentado en algún episodio, el auge de las herramientas “no code” está consiguiendo que la barrera de entrada se reduzca y al mismo tiempo, está consiguiendo el acceso a la tecnología web a un público con muchísimo que aportar a la experiencia de los sitios web.
+ + + +Para este episodio invitamos a Xavi Barrachina, impulsor de la comunidad Webflow Valencia y fundador de la agencia Masflow especializada en diseño web a través de la plataforma de diseño web no code Webflow. Xavi es un emprendedor nato, apasionado del diseño, la innovación y la estrategia creativa. Con él queremos hablar de Webflow y como esta innovadora herramienta puede ayudar a crear sitios web.
+ + + + + + + +Entre las cuestiones que hablamos con Xavi Barrachina:
+ + + +- ¿Qué es Webflow y qué lo diferencia de otras herramientas de creación web?
- ¿Cómo llegas a trabajar con Webflow y por qué te decides a montar Masflow?
- ¿Cómo te ayuda Webflow en tu proceso creativo?
- ¿Qué herramientas utilizas además de Webflow para crear los sitios web?
- ¿Crees que las tecnologías “no code” son el futuro del diseño web?
- ¿Qué aspectos del diseño web piensas que mejoran usando Webflow (relación con clientes, probar ideas o nuevos planteamientos, velocidad de puesta en funcionamiento)?
- Experiencia con la comunidad de Webflow Valencia y qué tipo de eventos habéis realizado.
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Restricting Flymake to my projects
+Manuel Uberti 21 11 2020
+My recent move from Flycheck to Flymake has proven to be a solid choice because
+the Emacs built-in syntax checker has yet to let me down. And since by now I am
+sure my love for project.el is absolutely obvious, could I miss the opportunity
+to make these two underappreciated gems shine together?
Honestly, though, the credit here goes all to Protesilaos Stavrou. His Flymake +setup made me aware of a neat way to limit the use of Flymake to the places +I actually need it.
+ +All I had to do was adapt it to my preferences:
+ +(defun mu-flymake-mode-activate ()
+ "Activate `flymake-mode' only in my projects."
+ (project--ensure-read-project-list)
+ (let ((known-projects (project-known-project-roots))
+ (pr (or (locate-dominating-file "." ".git")
+ default-directory)))
+ (if (and (eq buffer-read-only nil)
+ (member pr known-projects))
+ (flymake-mode +1)
+ (flymake-mode -1))))
+I then hooked this little function to prog-mode-hook and text-mode-hook and
+everything was good to go.
Note that project.el must be required before running mu-flymake-mode-activate,
+otherwise Emacs will complain about project--ensure-read-project-list not being
+available.
+
+ Restricting Flymake to my projects
+Manuel Uberti 21 11 2020
+My recent move from Flycheck to Flymake has proven to be a solid choice because
+the Emacs built-in syntax checker has yet to let me down. And since by now I am
+sure my love for project.el is absolutely obvious, could I miss the opportunity
+to make these two underappreciated gems shine together?
Honestly, though, the credit here goes all to Protesilaos Stavrou. His Flymake +setup made me aware of a neat way to limit the use of Flymake to the places +I actually need it.
+ +All I had to do was adapt it to my preferences:
+ +(defun mu-flymake-mode-activate ()
+ "Activate `flymake-mode' only in my projects."
+ (project--ensure-read-project-list)
+ (let ((known-projects (project-known-project-roots))
+ (pr (or (locate-dominating-file "." ".git")
+ default-directory)))
+ (if (and (eq buffer-read-only nil)
+ (member pr known-projects))
+ (flymake-mode +1)
+ (flymake-mode -1))))
+I then hooked this little function to prog-mode-hook and text-mode-hook and
+everything was good to go.
Note that project.el must be required before running mu-flymake-mode-activate,
+otherwise Emacs will complain about project--ensure-read-project-list not being
+available.
+ 
+
+
+ Feature Complete
+MonkeyUser 20 11 2020
+
+ 
+
+
+ TypeScript, the Mobile Web, and WebP website optimization! ⚡ — Pony Foo Weekly
+Pony Foo Weekly 19 11 2020
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
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+
+ Pixels vs. Bricks
+blog.karenying.com 19 11 2020
+
+ 
+
+
+ Acceptance
+MonkeyUser 18 11 2020
+
+
+
+
+ Kubernetes en producción con Antony Goetzschel
+República Web 15 11 2020
+En este episodio David Vaquero charla con Antony Ricardo Goetzschel CEO y fundador en la empresa alemana ccsolutions.io en Múnich y además, ingeniero DevOps en el grupo FunkeMedien, una de las mayores empresas de medios de comunicación de Alemania. Ricardo es un miembro muy activo en la comunidad Slack en español de Rancher, una plataforma para la administración de cluster de kubernetes, que permite desplegar y administrar clusters de kubernetes en varios proveedores, como Amazon, Azure, Google y OpenStack.
+ + + +Entre las cuestiones tratadas con Antony:
+ + + +- Primero hablamos de ti, ¿Cómo llega un venezolano a trabajar en una empresa alemana?
- ¿Cómo fue el proceso de selección?
- ¿Cuáles son las tareas que realizas en la empresa?
- Cuéntanos en qué consiste Kubernetes
- ¿Cuántos clústers tenéis ya en producción?
- ¿Cuáles son las características más destacables?¿Qué ofrece por encima de un despliegue tradicional?
- ¿Qué valoras más hasta la fecha de tu experiencia trabajando con Kubernetes?
- ¿Qué aspectos consideras más débiles de Kubernetes?
- ¿Tenéis una metodología GitOps?
- ¿Qué recursos son interesantes para Kubernetes y Rancher?¿Y en español?
- ¿Qué consejos puedes dar a alguien que quiere ser ingeniero de DevOps?
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Lisp Interview: more questions to CLPM author. Common Lisp at university for temporal reasoning and risk-bounded planning
+Lisp journey 15 11 2020
+Some days ago on reddit/r/lisp, +we got to (re)discover CLPM, the Common Lisp Package Manager.
+ +Its author, Eric Timmons aka daewok, was kind enough to give more context, and to answer some more questions of mine, about his use of Common Lisp in his university group.
+ +Below I’ll give an overview of CLPM, stress on how it differs from +Quicklisp, and then paste the interview.
+ +/Note/: it’s the same content as on reddit, but saved from oblivion!
+ + + +Table of Contents
+ +-
+
- CLPM + + +
CLPM
+ +Context
+ +++ +CLPM author here. I’m so happy (and shocked!) that people have found CLPM, especially given how little advertising I’ve done for it! I’m a PhD student in a group that does a large amount of our coding in Common Lisp. A big part of why I wrote CLPM, for better or worse, is that my group has not done a great job at versioning or maintaining backward compatibility of our various libraries throughout the years. I’m a very applications focused person and it was incredibly frustrating when I needed to deploy some of our code that had worked in the past but found that it bit rotted. And then when I would eventually get everything rolled back to the correct point in time I had no way to release a fix that was no longer applicable on the master branch (normally because the relevant API no longer existed or had been modified in a non-backward compatible way). So I hoped that encouraging/requiring actual version numbers would help us better communicate and reason about our changes over time (and be able to release minor changes to older versions of the code) and the locking capabilities would help save us in situations like giving a demo on short notice.
+ +I use CLPM as my daily driver as do a couple of the other Lisp-heavy students. It’s been going well so far, but I was planning to convert and get feedback from a few more before attempting to spread CLPM beyond my group. That’s unfortunately taken a lot longer than I wanted due to COVID, my personal life taking more time than normal (no worries, it’s for good reasons!), and just general research related tasks continuing to pop up.
+ +Now that the cat’s out of the bag though, I’d be happy to hear any feedback on it! I’m especially interested in the perspectives of people outside my group since I’ve been holding their hand in getting it set up and explaining my reasoning/goals to them almost every step of the way.
+
Feature set and comparison to Quicklisp
+ +CLPM’s project page (here’s a non-official GitHub mirror, if that helps you browse the repository) lists the project goals. Here’s my comment and comparison to Quicklisp.
+ +Support and encourage explicitly versioned systems
+ +++ +When a package upgrade introduces regressions, we should be able to use an older version.
+
But, that is currently not possible with the Quicklisp client, we must refer to other tools (Qlot) or manual workarounds.
+ +CLPM allows to use monthly-based releases, just as Quicklisp and from Quicklisp, but it also started a new source registry for Common Lisp libraries, which would:
+ +-
+
- allow to precisely pin dependencies. It is possible to do so in ASDF, but this propriety is not used in Quicklisp (or barely, or not by most of the library authors, because Quicklisp comes as monthly distributions anyways). +
- allow to get the library’s home URL, which surprisingly isn’t in Quicklisp’s metadata (last time I checked, I might be wrong). We have to look at the quicklisp-projects repository. +
- it would enforce the libraries to be on version control. Currently Quicklisp also accepts source files (as archives). +
Support installing multiple package versions, globally and locally
+ +CLPM allows to manage dependencies per project (per directory), and globally. With Quicklisp, it’s only globally. Otherwise we must rely to Qlot, or load projects more manually.
+ +While I personally find the Quicklisp approach great, simple to use, +sufficient in most cases and a better default than always pinning +dependencies manually, comes a point in a software life when we need +project-local dependencies.
+ +Support CI/CD workflows - ship pre-built binaries
+ +++ +CLPM is distributed in both binary and source form. Source for hackers or people who want to use a different feature set and binary for quick and easy installation in other cases.
+
That’s simpler to install, to use on CI systems, or to make you software’s users install the dependencies.
+ +Currently we can use Roswell to install Quicklisp libraries (and software) from the command line, but its installation isn’t crystal straightforward or super fast either.
+ +Minimize footprint in development images and deployments
+ +When you use CLPM and you build a binary of your program, the binary won’t contain CLPM (or only if you choose to). When we use Quicklisp, the built image contains Quicklisp (which can be very useful, I use it to live-reload running web apps).
+ +Support HTTPS
+ +Quicklisp currently doesn’t download packages through HTTPS.
+ +Cryptographic signature verification is coming.
+ +More questions to Eric Timmons - using Lisp at university for temporal reasoning and risk-bounded planning.
+ +What are you using CL for at your university?
+ +My group’s bread and butter is in temporal reasoning and risk-bounded planning and execution (including both activity and path planning). I’m personally working on a high-level language for specifying robotic information gathering missions and an executive to plan and dispatch the missions. Language wise I think you could say it’s a stripped down Screamer when it comes to non-deterministic programming and constraints, coupled with parallel and sequential operators and the ability to temporally constrain the relative execution time of different events in the program. There’s a few more things, such as support for expressing PDDL-like operators, but that’s the 10,000 foot view.
+ +I mentioned I’m applications focused and a lot of that focus of late has been on mission planning for autonomous underwater vehicles. Unfortunately, most of our code is running off the vehicles, but we’re slowing moving more reasoning onboard.
+ +Do you know other teams in your university that are using CL? (or, a lisp-like language?)
+ +I know other groups do but I’m not sure of the details, unfortunately.
+ +So, why CL? Does it have a killer feature that make your group use it? (it doesn’t have to have one though!)
+ +Ha, we started using CL long before I joined the group. From what I hear, it was originally mostly for practical reasons: it’s the language my group’s PI [Principal Investigator] knows the best and he needed to be able to hop onto any given project as students cycled on and off. But with respect to my personal research, I think CL is the best language for it. You can’t beat its macros for defining DSLs and I have a lot of DSLs both in my high level language (along with some MOP code!) and the planner. Something my advisor said to me about CL that really stuck with me is that it is a fantastic language to let you write a new language for the problem you want to solve, and specifying the problem is more than half the battle in solving it.
+ +Are there downsides, do you have difficulties in certain areas? (formation?)
+ +The biggest downside for us is that students rarely come into the group with CL experience and in rare cases some students refuse to really dive into our Lisp code and stick with something they’re more familiar with (such as Python) and end up reinventing poor facsimiles of things that exist.
+ +Ignoring that particular issue, using CL does add a non-trivial amount of time to on-boarding new students. Then beyond that, we had the aforementioned issues with not versioning correctly and not maintaining backward compatibility. While that’s really, at it’s core, a social issue that would exist regardless of language (and is hard to avoid given the natural turn-over rate of students), the lack of a package manager with features similar to those provided in the languages students come in knowing these days certainly didn’t help.
+ +How did you personally start with CL?
+ +I started with CL when I joined this group. I was given a URL to Practical Common Lisp and off I went. I kind of fell down the rabbit hole at some point and spent more time learning about the language than doing research (oops), but I think that’s paid off by this point as I can make CL do nearly anything I can think of. The first draft (or several…) of my code may not be pretty, but they’ll work, get the job done, and I can continue working on abstractions and mini-DSLs to my heart’s content whenever I need to make things more clear or performant.
+ +Can you tell us more about your software stack? (implementations, most loved libraries, deployment story (docker?), interface with other tools (monitoring?)…)
+ +We largely use SBCL these days. I routinely try to test on the other big Free implementations as well (ABCL, CCL, ECL) both out of a desire to be portable for portability sake and to make the code more widely useful if we ever get around to sharing it beyond our collaborators more (which I am cautiously hopeful will happen). I particularly love Hunchentoot, Drakma, basically anything from Edi Weitz, log4cl, closer-mop, and, of course, CFFI.
+ +We do a lot of our deployment with Docker (which is why I’m currently maintaining a number of CL related Docker images). I occasionally deploy things using Kubernetes (e.g., when we want to deploy our planners as a service for the students in my advisor’s classes to use). I personally love Kubernetes, but I’ve found that it’s difficult to get other students up to speed on it (let alone use it!) because it’s just one more set of things for them to learn when their focus is on graduating.
+ +We’re also working on getting more of our code running on ARM64 processors, since that’s largely what we have available to us for low-power robots. That’s proving to be a bit of a challenge, unfortunately because SBCL is fairly memory hungry and our algorithms are also inherently memory hungry. But in the end I think it’ll be fine as it’s a driving force to get us to do only the necessary reasoning onboard.
+ +We don’t have any great stories with regard to interfaces with other tools, but I have been meaning to pick up prometheus.cl and give it a try.
+ +Anything more to add?
+ +CL is awesome! Nothing else comes to mind right now.
+ ++ +
Thanks again Eric.
+ ++ +
+
+
+
+
+
+
+ Extending project.el
+Manuel Uberti 14 11 2020
+In my first appreciation of project.el I wrote about a patch for
+project--files-in-directory. It’s a working solution, I won’t deny that, but
+patching code always feels hacky. It’s like a dirty workaround you cannot avoid
+to look at every time you visit your Emacs configuration.
By inspecting the code of project.el I noticed that project-files is a generic
+function. In Emacs Lisp parlance, a generic function specifies an abstract
+operation with the actual implementation provided by methods1. This simply means
+that I can devise my own implementation of project-files.
(cl-defmethod project-root ((project (head local)))
+ (cdr project))
+
+(defun mu--project-files-in-directory (dir)
+ "Use `fd' to list files in DIR."
+ (let* ((default-directory dir)
+ (localdir (file-local-name (expand-file-name dir)))
+ (command (format "fd -t f -0 . %s" localdir)))
+ (project--remote-file-names
+ (sort (split-string (shell-command-to-string command) "\0" t)
+ #'string<))))
+
+(cl-defmethod project-files ((project (head local)) &optional dirs)
+ "Override `project-files' to use `fd' in local projects."
+ (mapcan #'mu--project-files-in-directory
+ (or dirs (list (project-root project)))))
+project.el has to be made aware of my local type now.
(defun mu-project-try-local (dir)
+ "Determine if DIR is a non-Git project.
+DIR must include a .project file to be considered a project."
+ (let ((root (locate-dominating-file dir ".project")))
+ (and root (cons 'local root))))
+mu-project-try-local just needs to be added to project-find-functions to
+make sure my non-Git projects become known and remembered across sessions when
+I hit C-x p p. This is way more elegant than the previous patch.
Since I also never use Git submodules, I can push my extensions a little further.
+ +(defun mu--backend (dir)
+ "Check if DIR is under Git, otherwise return nil."
+ (when (locate-dominating-file dir ".git")
+ 'Git))
+
+(defun mu-project-try-vc (dir)
+ "Determine if DIR is a project.
+This is a thin variant of `project-try-vc':
+- It takes only Git into consideration
+- It does not check for submodules"
+ (let* ((backend (mu--backend dir))
+ (root
+ (when (eq backend 'Git)
+ (or (vc-file-getprop dir 'project-git-root)
+ (let ((root (vc-call-backend backend 'root dir)))
+ (vc-file-setprop dir 'project-git-root root))))))
+ (and root (cons 'vc root))))
+mu-project-try-vc now replaces project-try-vc in project-find-functions.
Notes
+ +
+
+
+ -
+
-
+
See Generic Functions in the manual. ↩
+
+
+
+ Extending project.el
+Manuel Uberti 14 11 2020
+In my first appreciation of project.el I wrote about a patch for
+project--files-in-directory. It’s a working solution, I won’t deny that, but
+patching code always feels hacky. It’s like a dirty workaround you cannot avoid
+to look at every time you visit your Emacs configuration.
By inspecting the code of project.el I noticed that project-files is a generic
+function. In Emacs Lisp parlance, a generic function specifies an abstract
+operation with the actual implementation provided by methods1. This simply means
+that I can devise my own implementation of project-files.
(cl-defmethod project-root ((project (head local)))
+ (cdr project))
+
+(defun mu--project-files-in-directory (dir)
+ "Use `fd' to list files in DIR."
+ (let* ((default-directory dir)
+ (localdir (file-local-name (expand-file-name dir)))
+ (command (format "fd -t f -0 . %s" localdir)))
+ (project--remote-file-names
+ (sort (split-string (shell-command-to-string command) "\0" t)
+ #'string<))))
+
+(cl-defmethod project-files ((project (head local)) &optional dirs)
+ "Override `project-files' to use `fd' in local projects."
+ (mapcan #'mu--project-files-in-directory
+ (or dirs (list (project-root project)))))
+project.el has to be made aware of my local type now.
(defun mu-project-try-local (dir)
+ "Determine if DIR is a non-Git project.
+DIR must include a .project file to be considered a project."
+ (let ((root (locate-dominating-file dir ".project")))
+ (and root (cons 'local root))))
+mu-project-try-local just needs to be added to project-find-functions to
+make sure my non-Git projects become known and remembered across sessions when
+I hit C-x p p. This is way more elegant than the previous patch.
Since I also never use Git submodules, I can push my extensions a little further.
+ +(defun mu--backend (dir)
+ "Check if DIR is under Git, otherwise return nil."
+ (when (locate-dominating-file dir ".git")
+ 'Git))
+
+(defun mu-project-try-vc (dir)
+ "Determine if DIR is a project.
+This is a thin variant of `project-try-vc':
+- It takes only Git into consideration
+- It does not check for submodules"
+ (let* ((backend (mu--backend dir))
+ (root
+ (when (eq backend 'Git)
+ (or (vc-file-getprop dir 'project-git-root)
+ (let ((root (vc-call-backend backend 'root dir)))
+ (vc-file-setprop dir 'project-git-root root))))))
+ (and root (cons 'vc root))))
+mu-project-try-vc now replaces project-try-vc in project-find-functions.
Notes
+ +
+
+
+ -
+
-
+
See Generic Functions in the manual. ↩
+
+
+ 
+
+
+ You can buy a preview of the Common Lisp Cookbook in ePub
+Lisp journey 13 11 2020
+
See here: https://ko-fi.com/s/01fee22a32
+ +Let me try something: I propose you here to buy the ePub, even though it is meant to be available for free.
+ +I contributed quite a lot to the Cookbook and I found since the +beginning that having an EPUB and/or a PDF version would be very +useful. Some years later, nobody did it, and I finally wrote a script +to bundle all the pages together and generate an ePub, and then a +PDF. It isn’t finished though, it needs more editing, and it would +also be great to write a proper LaTeX style for the PDF. As I have one +version on disk, I thought on giving potential supporters the +opportunity to read it and fund the remaining work, or simply give a sign of +encouragement. It’s also the opportunity for me to try this new Ko-fi +feature, and to practice speaking about financial support…
+ +Let’s turn it another way: if you support me, here’s a reward for you, an exclusivity. +And in any case, hold on, this ePub will eventually be available for everybody.
+ +Thanks!
+ ++ +
ps: About money: yes, it does a difference right now, because I don’t +have a fixed, nor big, income. I am trying to live on my free software +activities. I have a few clients, but not enough, so I’m trying to +diversify and get some earnings from my Lisp work. I even pay lisp +contributors to write free software (we are currently adding Stripe +payments to a web application. When it’s done, you’ll know everything +about it). So, the money has an impact.
+ +
+ 
+
+
+ Instapaper now available on macOS
+Instapaper 11 11 2020
+We’re excited to announce that Instapaper is now available on macOS! You can download Instapaper from the App Store on your Mac to read all your articles offline, in full screen mode, and with all the great features from the iOS app.
We customized the interfaces and features to make the app feel interactive and at home on Mac. This includes a side-by-side view of folders and article list, and hover states to highlight content on mouseover.
We also included new features for managing articles like hover actions, which allows you to easily like, move, archive, and delete directly from the list. With drag & drop, you can quickly organize articles directly into folders.
Instapaper for Mac has full keyboard navigation support, so you can navigate, read, and manage your articles using only the keyboard. Here are some of the supported keyboard shortcuts:
Navigation
- ↑: Previous Item
- ↓: Next Item
- ⏎: Select Item
- Space: Page Down
- ⇧Space: Page Up
- ⌘F: Search
- ⇧⌘F: Search All Articles
- ⌘,: Preferences
- ⌘←: Navigate Back
Article Management
- ⌘R: Refresh Articles
- ⇧⌘A: Archive Article
- ⇧⌘D: Delete Article
- ⇧⌘M: Move Article
Appearance
- ⌘1: Light Mode
- ⌘2: Sepia Mode
- ⌘3: Gray Mode
- ⌘4: Dark Mode
All available shortcuts can be found in the app menu bar located at the top of the screen.
Instapaper for macOS supports Intel and Apple Silicon Macs.
Instapaper iOS 8.0
Today we are also announcing the release of Instapaper iOS 8.0. This release contains a number of improvements that laid the foundation for building the macOS app, and also includes a few iOS-specific updates.
We redesigned the share sheet to be faster and easier to use. After saving, simply swipe down to dismiss and return to the app you were using. It’s a small change that makes a big difference in saving speed.
Additionally, we improved the pagination feature so there’s less text clipping in a variety of different situations.
That’s Instapaper 8.0 for iOS and macOS! Instapaper for Mac has been a long standing request from our customers, and we’re really excited to bring all of the great functionality from iOS to macOS.
As always, we want to hear your questions, feature requests, and/or issues. That feedback directly informs our roadmap, and we’d love to hear from you via email to support@help.instapaper.com or @InstapaperHelp on Twitter.
Thank you for using Instapaper!
– Instapaper Team
+
+ 
+
+
+ Effort Splitting
+MonkeyUser 10 11 2020
+
+
+
+
+ Front es el nuevo full stack y digitalización made in Spain
+República Web 08 11 2020
+Si bien en la mayoría de los episodios nos centramos en una cuestión o entrevista, para este episodio hemos seleccionado dos artículos y una noticia de interés para la profesión del desarrollo web. Empezamos comentando el artículo de Chris Coyier publicado en lncrement y que lleva por título When frontend means full stack. Continuamos con una noticia reciente aparecida en Valencia Plaza y que hace referencia al descubrimiento de un grave error de seguridad en el acceso a una aplicación móvil. Por último comentamos la columna de opinión publicada en el digital El Confidencial por Eduardo Manchón y que lleva por título Las consultoras están matando al industria: la digitalización ‘made in Spain’ hace agua.
+ + + +Cuando el frontend quiere decir full stack
+ + + +El artículo escrito por el conocido desarrollador Chris Coyier dibuja un acertada línea sobre el estado actual de la profesión del desarrollador frontend. Según comenta Coyier en su artículo, «los desarrolladores de frontend se están haciendo preguntas que alguna vez habrían sido respondidas exclusivamente por los desarrolladores de backend». Los artículos de Chris Coyier suelen analizar con bastante certeza, la situación actual de la profesión. En este artículo se muestra cómo ha evolucionado el perfil del desarrollador web, las habilidades que se le piden a una persona encargada de la parte del frontal y cómo hoy en día, las opciones para la construcción de un sitio web, son enormemente complejas y también diversas.
+ + + +Quizás una de las mejores frases del artículo sea que «el término «full stack» ha llegado a significar en gran medida «un desarrollador de frontend que hace una buena cantidad de las cosas que un desarrollador de backend solía hacer».
+ + + +App deja al descubierto datos personales de miles de vecinos de Valencia
+ + + +Andros nos cuenta esta noticia aparecida recientemente en el digital Valencia Plaza, en el que se cuenta como un profesor de la Universidad de Valencia, halló importantes defectos de seguridad en la aplicación de la empresa encargada de la gestión de aguas en Valencia.
+ + + +Como comenta Andros, en el momento de comprobar él mismo esta información, el acceso a la app de la empresa había sido bloqueado y no se había informado del problema a los usuarios. También comentamos lo sorprendente que resulta que desde la empresa afectada, respondan que «se requieren unos mínimos conocimientos de informática para detectarlos».
+ + + + + + + +Digitalización made in Spain hace agua
+ + + +Para seguir con el mundo de las consultoras y de las aguas (curiosamente), David comenta la reciente columna de Eduardo Manchón, donde se relata el sistema de desarrollo tecnológico en España, a través de consultoras. Según explica el autor del artículo «las empresas españolas han cometido el error de delegar su digitalización y dejarla en manos de consultoras».
+ + + +Este artículo pone de manifiesto la necesidad de crear desde dentro de las empresas, una cultura tecnológica liderada por personas que comprendan bien como sea desarrollan los negocios en una economía digital. Como indica muy bien Manchón, «la digitalización es mucho más que crear una web o una ‘app’, es un aprendizaje que implica cambios profundos en las personas y en el funcionamiento de las organizaciones».
+ + + +En definitiva, un episodio diferente y con diversidad de temas orientados a la profesión del desarrollo y la tecnología en internet.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Boost Visual Accessibility by Auto Flipping Text Color
+blog.karenying.com 07 11 2020
+
+
+ October 2020 Monthly Update
+News on Clojurists Together 04 11 2020
+
+ 
+
+
+ Election
+MonkeyUser 03 11 2020
+
+
+ Chasing the Pixel-Perfect Dream
+Josh Comeau's blog 02 11 2020
+
+
+
+
+ Quasar un framework Vue.js para gobernarlos a todos con Salvador Santander
+República Web 01 11 2020
+Invitamos a un buen amigo de este podcast para hablar sobre Quasar, un completo framework para Vue.js dirigido a crear interfaces de alto rendimiento sobre diferentes tecnologías. Salvador Santander es técnico de desarrollo en la sección de Informática de la Agencia de Vivienda y Rehabilitación de Andalucía (AVRA), donde se encarga del desarrollo de los sitios webs de la empresa, la arquitectura de aplicaciones y el desarrollo de aplicaciones webs.
+ + + +Salvador nos cuenta las innumerables ventajas que ha encontrado al trabajar con Quasar y como lo está incorporando en los proyectos que desarrolla dentro de AVRA. A diferencia de otros frameworks para Vue.js, Quasar tiene como punto fuerte ser una solución única para la mayoría de necesidades presentes en un proyecto web moderno. Quasar dispone de una completísima colección de componentes basados en Material Design y permite desarrollar proyectos para SPA, SSR, PWA, aplicaciones móviles híbridas, extensiones de navegador y hasta aplicaciones de escritorio a través de Electron.
+ + + +Entre las cuestiones que hablamos con Salvador:
+ + + +-
+
- En qué consiste Quasar y cómo has llegado a trabajar con este framework Vue.js +
- ¿Cuáles son las características más destacables? +
- ¿Qué valoras más hasta la fecha de tu experiencia trabajando con Quasar? +
- ¿Qué aspectos consideras más débiles de Quasar? +
- ¿Qué proyecto/s estáis haciendo con Quasar? +
- ¿Qué tecnologías tienes en tu radar? +
Salvador Santander es un buen ejemplo de cómo en la Administración Pública se desarrollan proyectos con tecnologías nuevas y cómo se trabaja para mejorar el acceso a la información para los ciudadanos.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Q3 2020 Survey Results
+News on Clojurists Together 28 10 2020
+
+ 
+
+
+ Get Funded
+MonkeyUser 27 10 2020
+
+
+ v2.0 Stable Release
+blog.karenying.com 25 10 2020
+
+
+
+
+ Wikimedia es mucho más que Wikipedia con Rubén Ojeda
+República Web 25 10 2020
+Para este episodio contamos con la compañía de Rubén Ojeda, coordinador de proyectos en Wikimedia España, la asociación sin ánimo de lucro que promueve el conocimiento libre y los proyectos Wikimedia, siendo Wikipedia el más conocido de todos. Pero Wikimedia es mucho más que la Wikipedia, y en este episodio Rubén nos contará todo el trabajo que se realiza desde la asociación y cómo favorecen un mejor acceso a la cultura y el conocimiento libre.
+ + + +Wikimedia está detrás de proyectos de difusión tan interesantes como Wikidata, Wikimedia Commons, Wikiquote o Wikisource, pero también de otros muchos que constituyen un formidable repositorio de información compartida y libre.
+ + + +Con Rubén Ojeda hablamos mucho sobre Wikipedia pero también de varias cuestiones sobre Wikimedia y sus proyectos:
+ + + +-
+
- ¿Qué es la Asociación Wikimedia España y cómo se constituye aquí? +
- En qué consiste una wiki y cómo se organiza a nivel editorial. +
- ¿Cómo pueden participar los ciudadanos de los proyectos Wikimedia? +
- ¿Conoce el sector público y las instituciones culturales cómo compartir conocimiento a través de vuestros proyectos? +
- ¿Cuáles son las mayores amenazas al conocimiento libre en la era digital? +
- ¿Cómo pueden ayudar los proyectos Wikimedia a combatir la desinformación? +
En definitiva una conversación muy completa para conocer la labor de Wikimedia, aspectos sobre derechos digitales, contenidos libres y conocer cómo poder colaborar en los proyectos.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Summer of Bugs Update 2020
+News on Clojurists Together 24 10 2020
+
+
+ Emacs and Emanuele Severino
+Manuel Uberti 24 10 2020
+The recently available Emacs User Survey made me think, once again, about the
+status of the technological world around me. The survey was painstakingly
+discussed on the emacs-devel mailing list, and generated some interesting
+reactions among people outside the core developing team as well. More
+interesting for the perspective of this writing are the reactions to the
+discussions on emacs-devel, because they reveal how great the distance between
+me and some members of the Emacs community has been getting.
You see, I am a failed Free Software supporter. I stopped campaigning in its +favour as soon as my wife’s school closed. There I had set up everything with +Free and Open Source software, and watching the teachers effectively do their +job with technological solutions they were not accustomed to made me happy. They +did not really care about the reasons behind my choices, but they respected my +contribution and were willing to overcome the first weeks of adaptation as long +as I could guarantee a comfortable working environment. When all of this ended +and I went back to software development, Free and Open Source software became +only a private concern. While still set on Linux1, I left Debian for Ubuntu +because I didn’t want to spend time tinkering with my operative system to get +the best out of my Dell XPS. My distro-hopping days had come to an end. I just +wanted a system that would let me code, write, and browse the Web. I chose the +easy way.
+ +However, I have never stopped paying attention to the world around me and +behaving consciously. For instance, I hate wasting technology. The +3-and-a-half-year old Dell XPS where I am writing now replaced my 8-year old +Dell Inspiron, and my 7-year old HP server is still rock-solid and here to stay. +I have a 4-year old Fairphone, my first and only smartphone, that I intend to +keep for as long as possible. Beside gadgets, I’ve been on a vegan diet for +almost seven years and I consider it one of the best and most important choices +I’ve ever made regarding the ethics of what I eat. Come to think of it, as bad +as the Coronavirus crisis is turning out to be, it “fixed” the problem of +getting to the office every day, cutting my car usage down to once a week for +groceries2 and thus decreasing my impact on the environment.
+ +This is why mixing technocraticism with pragmatism bothers me. The words +“pragmatic” and “pragmatism” have been kind of a constant in the IT world I live +in since “The Pragmatic Programmer” passed on my shelves. As every word in every +language, “pragmatic” and “pragmatism” are complex words and their actual +meaning is not trivially describable. Immanuel Kant distinguishes between +“practical” and “pragmatic”, but without asking him we can quickly see what the +dictionary tells us. According to the Oxford Learner’s Dictionary, “pragmatic” +means “solving problems in a practical and sensible way rather than by having +fixed ideas or theories”. Treccani, however, is closer to how “pragmatic” is +known nowadays: “what is being characterised by the prevailing of practical +interests over theoretical ones and ideal values”. I won’t digress on the +multiple meanings of “ideal” to keep it simple and because “values” is actually +the key word for me here.
+ +“Pragmatic” and “pragmatism”, in common parlance, imply a separation between +theoretical thoughts and practical action, but it is actually impossible to draw +a line between the two. Every action is informed by a thought and every thought +shines a light on the action. We can act automatically without thinking about +it, sure, but that has nothing to do with voluntary actions. When we act, we act +according to a line of reasoning, and it’s that line of reasoning that +determines the value of the action. Take my choice of using Ubuntu on this Dell +XPS. A deliberate decision born out of my desire to prefer a comfortable option +instead of spending time to value more Free Software-compliant solutions. +I acted with a plan just as I acted with a plan when I chose my vegan diet. +Which choice is more pragmatic? Which one tells you more about my ethics?
+ +For years now I’ve been seeing the IT world as self-involved and rarely eager to +discuss larger issues. Problems such as the environmental crisis become material +for self-congratulatory speeches at conferences around the world, while in fact +the day after the conference we resume our lives as if nothing other than +ourselves mattered. We do that because, as Emanuele Severino says, we are scared +of what is beyond ourselves. We have replaced religious myths with the myth of +technology to find the immediate answers to deep and life-changing questions +that we do not want to investigate any further.
+ +It’s not easy to understand the weight of words like “pragmatism” and +“pragmatic” in a technocratic world. We live in an age where we believe that +technology is our ultimate saviour. We are driven to accept technology as it is +because of the benefits it brings to ourselves. We trust our technology because +not doing so would result in the effort of questioning it, which in turns may +unveil the details that the technocratic world goes a long distance to hide. +More importantly, questioning technology could disclose what we really are and +need to be, something that takes will and courage to face. In a time like this, +Emanuele Severino’s claim that technique is the dominant power of our time +sounds as forceful as ever.
+ +Notes
+ + + +
+
+ Emacs and Emanuele Severino
+Manuel Uberti 24 10 2020
+The recently available Emacs User Survey made me think, once again, about the
+status of the technological world around me. The survey was painstakingly
+discussed on the emacs-devel mailing list, and generated some interesting
+reactions among people outside the core developing team as well. More
+interesting for the perspective of this writing are the reactions to the
+discussions on emacs-devel, because they reveal how great the distance between
+me and some members of the Emacs community has been getting.
You see, I am a failed Free Software supporter. I stopped campaigning in its +favour as soon as my wife’s school closed. There I had set up everything with +Free and Open Source software, and watching the teachers effectively do their +job with technological solutions they were not accustomed to made me happy. They +did not really care about the reasons behind my choices, but they respected my +contribution and were willing to overcome the first weeks of adaptation as long +as I could guarantee a comfortable working environment. When all of this ended +and I went back to software development, Free and Open Source software became +only a private concern. While still set on Linux1, I left Debian for Ubuntu +because I didn’t want to spend time tinkering with my operative system to get +the best out of my Dell XPS. My distro-hopping days had come to an end. I just +wanted a system that would let me code, write, and browse the Web. I chose the +easy way.
+ +However, I have never stopped paying attention to the world around me and +behaving consciously. For instance, I hate wasting technology. The +3-and-a-half-year old Dell XPS where I am writing now replaced my 8-year old +Dell Inspiron, and my 7-year old HP server is still rock-solid and here to stay. +I have a 4-year old Fairphone, my first and only smartphone, that I intend to +keep for as long as possible. Beside gadgets, I’ve been on a vegan diet for +almost seven years and I consider it one of the best and most important choices +I’ve ever made regarding the ethics of what I eat. Come to think of it, as bad +as the Coronavirus crisis is turning out to be, it “fixed” the problem of +getting to the office every day, cutting my car usage down to once a week for +groceries2 and thus decreasing my impact on the environment.
+ +This is why mixing technocraticism with pragmatism bothers me. The words +“pragmatic” and “pragmatism” have been kind of a constant in the IT world I live +in since “The Pragmatic Programmer” passed on my shelves. As every word in every +language, “pragmatic” and “pragmatism” are complex words and their actual +meaning is not trivially describable. Immanuel Kant distinguishes between +“practical” and “pragmatic”, but without asking him we can quickly see what the +dictionary tells us. According to the Oxford Learner’s Dictionary, “pragmatic” +means “solving problems in a practical and sensible way rather than by having +fixed ideas or theories”. Treccani, however, is closer to how “pragmatic” is +known nowadays: “what is being characterised by the prevailing of practical +interests over theoretical ones and ideal values”. I won’t digress on the +multiple meanings of “ideal” to keep it simple and because “values” is actually +the key word for me here.
+ +“Pragmatic” and “pragmatism”, in common parlance, imply a separation between +theoretical thoughts and practical action, but it is actually impossible to draw +a line between the two. Every action is informed by a thought and every thought +shines a light on the action. We can act automatically without thinking about +it, sure, but that has nothing to do with voluntary actions. When we act, we act +according to a line of reasoning, and it’s that line of reasoning that +determines the value of the action. Take my choice of using Ubuntu on this Dell +XPS. A deliberate decision born out of my desire to prefer a comfortable option +instead of spending time to value more Free Software-compliant solutions. +I acted with a plan just as I acted with a plan when I chose my vegan diet. +Which choice is more pragmatic? Which one tells you more about my ethics?
+ +For years now I’ve been seeing the IT world as self-involved and rarely eager to +discuss larger issues. Problems such as the environmental crisis become material +for self-congratulatory speeches at conferences around the world, while in fact +the day after the conference we resume our lives as if nothing other than +ourselves mattered. We do that because, as Emanuele Severino says, we are scared +of what is beyond ourselves. We have replaced religious myths with the myth of +technology to find the immediate answers to deep and life-changing questions +that we do not want to investigate any further.
+ +It’s not easy to understand the weight of words like “pragmatism” and +“pragmatic” in a technocratic world. We live in an age where we believe that +technology is our ultimate saviour. We are driven to accept technology as it is +because of the benefits it brings to ourselves. We trust our technology because +not doing so would result in the effort of questioning it, which in turns may +unveil the details that the technocratic world goes a long distance to hide. +More importantly, questioning technology could disclose what we really are and +need to be, something that takes will and courage to face. In a time like this, +Emanuele Severino’s claim that technique is the dominant power of our time +sounds as forceful as ever.
+ +Notes
+ + + +
+ 
+
+
+ Corporate Solution
+MonkeyUser 23 10 2020
+
+ 
+
+ Cloudflare Analytics review
+Marko Saric 20 10 2020
+
+
+ The Surprising Impact of Medium-Size Texts on PostgreSQL Performance
+Haki Benita 19 10 2020
+Any database schema is likely to have plenty of text fields. In this article I demonstrate the surprising impact of medium-size texts on query performance.
+
+
+
+
+ Virtualización y contenedores con Sergio López
+República Web 18 10 2020
+Para este episodio contamos con la compañía desde Zaragoza con Sergio López, un desarrollador de software especializado en Sistemas Operativos y Virtualización. Con Sergio queremos trazar a grandes rasgos las diferencias existentes entre la virtualización y los contenedores. Sergio López @slpnix nos cuenta los fundamentos de estas dos tecnologías, que sin duda, han revolucionado el mundo de la computación y son una de las bases de la nube.
+ + + +Con Sergio tratamos las siguientes cuestiones:
+ + + +-
+
- ¿Qué es la virtualización y cómo ha cambiado esta tecnología el mundo de la informática? +
- ¿Qué necesitamos para virtualizar una computadora y qué influye en su rendimiento? +
- ¿Qué tipos de virtualización existen y cuáles son sus diferencias? +Ejemplos y gestión de hipervisores. +
- ¿Qué son los contenedores y cuál es su origen?. +
- ¿Qué tipos de tecnología de contenedores existen?. +
- Presente y futuro de las tecnologías. Principales empresas y proyectos. +
- Referencias y recursos de interés. +
Si queréis escuchar a Sergio López, participó también recientemente en el Podcast Entre Devs y Ops hablando sobre Microkernels. De hecho, esta entrevista le sirvió a Andros para invitar a Sergio al programa.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Customize Chrome New Tab Page in 30 Seconds
+blog.karenying.com 16 10 2020
+
+
+ Reliable REPL switching and buffer loading with CIDER
+Manuel Uberti 16 10 2020
+As a Clojure developer one of the most important packages in my everyday Emacs +usage is CIDER. There are many things to love about it, chief among them the +great interactive code evaluation and a sweet integration with popular Clojure +tools. I still haven’t played with its debugging facilities, but yes, I know I should.
+ +However, there is something that has been bothering me for quite a while: REPL +switching and buffer loading. I cannot pinpoint the exact moment when these +seemingly simple operations have become so unreliable, but I still remember when +switching to the correct REPL buffer according to the file in front of me used +to work as expected and loading a buffer didn’t require dealing with sessions +first.
+ +Let me give you more details before this writing starts to look like a random
+rant. My projects are usually web applications, which means I have to write both
+Clojure and ClojureScript. The Clojure side can be backed by leiningen or a
+deps.edn file, and we are set on shadow-cljs for ClojureScript. The first thing
+I normally do is jack-in with C-c C-x j j and then bring up the dedicated
+ClojureScript REPL with C-c C-x j s. Opening the browser and navigate to
+something along the lines of localhost:3000 finalises the process of setting up
+the ClojureScript REPL. That’s it, another good day of coding can begin. And
+soon enough frustration follows.
I tend to move from Clojure to ClojureScript files and vice versa quite a lot, +and hitting C-c C-z frequently results in an unpredictable behaviour. Sometimes +the REPL of the expected type pops up, sometimes the other one appears, +sometimes I get a message about a missing REPL in the current session. Manually +linking the current buffer to the correct REPL with C-c C-s b seems to fix the +problem, but it’s only a matter of time. It takes a couple of buffer switching +operations to bring the issue back. It is as if the link between the buffer and +the REPL has vanished. Even worse, without that link I can forget about C-c C-k +to load the buffer.
+ +To overcome my frustration, I sat back and looked at how exactly I interact with +CIDER:
+ +-
+
- I only deal with one project at a time +
- I need at most two running REPLs +
- I don’t really care about firing up dedicated REPLs for other projects. If +I change project, I simply close every buffer of the current one and start +afresh +
This made me realise that the whole CIDER session management is too much for my +basic needs.
+ +(defun mu--cider-repl-regex (type)
+ "Return the regexp to get the CIDER REPL based on TYPE."
+ (if (eq type 'clj)
+ "\`*cider-repl .*clj[*]"
+ "\`*cider-repl .*cljs"))
+
+(defun mu--cider-repl-buffer-name (type)
+ "Get buffer from `buffer-list' according to TYPE."
+ (let ((regex (mu--cider-repl-regex type)))
+ (car (seq-filter (lambda (s) (string-match-p regex s))
+ (mapcar #'buffer-name (buffer-list))))))
+
+(defun mu-cider-switch-to-repl (&optional type)
+ "Open a CIDER REPL for TYPE.
+If TYPE is not passed, open a Clojure REPL."
+ (interactive "P")
+ (let ((type (or type 'clj)))
+ (if-let (buffer (mu--cider-repl-buffer-name type))
+ (pop-to-buffer buffer)
+ (message "No CIDER REPL available"))))
+
+(defun mu-cider-switch-to-cljs-repl ()
+ "Open a CIDER REPL for ClojureScript."
+ (interactive)
+ (mu-cider-switch-to-repl 'cljs))
+Note that I changed the value of nrepl-repl-buffer-name-template to *cider-repl
+%j %r:%S*, so you may have to change mu--cider-repl-regex according to the value
+in your setup.
C-c C-z is bound to mu-cider-switch-to-repl in clojure-mode-map and
+clojurec-mode-map, and to mu-cider-switch-to-cljs-repl in
+clojurescript-mode-map. This of course means that in .cljc files I always get to
+a Clojure REPL, but that’s fine. The code in there has to be tested on both
+REPLs anyway, so it doesn’t matter which one comes up first.
Now, let’s fix C-c C-k as well.
+ +(defun mu--cider-session-by-type (type)
+ "Return the current CIDER session by TYPE."
+ (let* ((regex (mu--cider-repl-regex type))
+ (system (sesman--system))
+ (sessions (sesman-current-sessions system '(buffer))))
+ (car
+ (seq-filter (lambda (s)
+ (string-match-p regex (buffer-name (cadr s))))
+ sessions))))
+
+(defun mu--cider-load-buffer (session)
+ "Load the current buffer according to SESSION."
+ (if session
+ (let ((system (sesman--system))
+ (buf (current-buffer)))
+ (sesman--clear-links)
+ (sesman-link-session system session 'buffer buf)
+ (cider-load-buffer buf))
+ (message "No CIDER REPL available")))
+
+(defun mu-cider-load-clj-buffer ()
+ "Load the current Clojure buffer."
+ (interactive)
+ (mu--cider-load-buffer (mu--cider-session-by-type 'clj)))
+
+(defun mu-cider-load-cljc-buffer ()
+ "Load the current ClojureC buffer."
+ (interactive)
+ (let ((clj-session (mu--cider-session-by-type 'clj))
+ (cljs-session (mu--cider-session-by-type 'cljs)))
+ (if (and (null clj-session)
+ (null cljs-session))
+ (message "No CIDER REPL available")
+ (when clj-session
+ (mu--cider-load-buffer clj-session))
+ (when cljs-session
+ (mu--cider-load-buffer cljs-session)))))
+
+(defun mu-cider-load-cljs-buffer ()
+ "Load the current ClojureScript buffer."
+ (interactive)
+ (mu--cider-load-buffer (mu--cider-session-by-type 'cljs)))
+Just like for C-c C-z, C-c C-k is now bound to these commands according to the
+mode map. For the sake of completeness, I have also disabled both C-c C-k and
+C-c C-z in cider-mode-map in order to avoid any kind of overshadowing by CIDER.
Note that this approach works well with my intended CIDER usage. It may not be +what you are looking for if you are experiencing the same problems with REPL +switching and buffer loading. Still, I have been using these commands for a +while now and I am happy with them. CIDER has become my trusted Clojure IDE +again.
+ +
+
+ Reliable REPL switching and buffer loading with CIDER
+Manuel Uberti 16 10 2020
+As a Clojure developer one of the most important packages in my everyday Emacs +usage is CIDER. There are many things to love about it, chief among them the +great interactive code evaluation and a sweet integration with popular Clojure +tools. I still haven’t played with its debugging facilities, but yes, I know I should.
+ +However, there is something that has been bothering me for quite a while: REPL +switching and buffer loading. I cannot pinpoint the exact moment when these +seemingly simple operations have become so unreliable, but I still remember when +switching to the correct REPL buffer according to the file in front of me used +to work as expected and loading a buffer didn’t require dealing with sessions +first.
+ +Let me give you more details before this writing starts to look like a random
+rant. My projects are usually web applications, which means I have to write both
+Clojure and ClojureScript. The Clojure side can be backed by leiningen or a
+deps.edn file, and we are set on shadow-cljs for ClojureScript. The first thing
+I normally do is jack-in with C-c C-x j j and then bring up the dedicated
+ClojureScript REPL with C-c C-x j s. Opening the browser and navigate to
+something along the lines of localhost:3000 finalises the process of setting up
+the ClojureScript REPL. That’s it, another good day of coding can begin. And
+soon enough frustration follows.
I tend to move from Clojure to ClojureScript files and vice versa quite a lot, +and hitting C-c C-z frequently results in an unpredictable behaviour. Sometimes +the REPL of the expected type pops up, sometimes the other one appears, +sometimes I get a message about a missing REPL in the current session. Manually +linking the current buffer to the correct REPL with C-c C-s b seems to fix the +problem, but it’s only a matter of time. It takes a couple of buffer switching +operations to bring the issue back. It is as if the link between the buffer and +the REPL has vanished. Even worse, without that link I can forget about C-c C-k +to load the buffer.
+ +To overcome my frustration, I sat back and looked at how exactly I interact with +CIDER:
+ +-
+
- I only deal with one project at a time +
- I need at most two running REPLs +
- I don’t really care about firing up dedicated REPLs for other projects. If +I change project, I simply close every buffer of the current one and start +afresh +
This made me realise that the whole CIDER session management is too much for my +basic needs.
+ +(defun mu--cider-repl-regex (type)
+ "Return the regexp to get the CIDER REPL based on TYPE."
+ (if (eq type 'clj)
+ "\`*cider-repl .*clj[*]"
+ "\`*cider-repl .*cljs"))
+
+(defun mu--cider-repl-buffer-name (type)
+ "Get buffer from `buffer-list' according to TYPE."
+ (let ((regex (mu--cider-repl-regex type)))
+ (car (seq-filter (lambda (s) (string-match-p regex s))
+ (mapcar #'buffer-name (buffer-list))))))
+
+(defun mu-cider-switch-to-repl (&optional type)
+ "Open a CIDER REPL for TYPE.
+If TYPE is not passed, open a Clojure REPL."
+ (interactive "P")
+ (let ((type (or type 'clj)))
+ (if-let (buffer (mu--cider-repl-buffer-name type))
+ (pop-to-buffer buffer)
+ (message "No CIDER REPL available"))))
+
+(defun mu-cider-switch-to-cljs-repl ()
+ "Open a CIDER REPL for ClojureScript."
+ (interactive)
+ (mu-cider-switch-to-repl 'cljs))
+Note that I changed the value of nrepl-repl-buffer-name-template to *cider-repl
+%j %r:%S*, so you may have to change mu--cider-repl-regex according to the value
+in your setup.
C-c C-z is bound to mu-cider-switch-to-repl in clojure-mode-map and
+clojurec-mode-map, and to mu-cider-switch-to-cljs-repl in
+clojurescript-mode-map. This of course means that in .cljc files I always get to
+a Clojure REPL, but that’s fine. The code in there has to be tested on both
+REPLs anyway, so it doesn’t matter which one comes up first.
Now, let’s fix C-c C-k as well.
+ +(defun mu--cider-session-by-type (type)
+ "Return the current CIDER session by TYPE."
+ (let* ((regex (mu--cider-repl-regex type))
+ (system (sesman--system))
+ (sessions (sesman-current-sessions system '(buffer))))
+ (car
+ (seq-filter (lambda (s)
+ (string-match-p regex (buffer-name (cadr s))))
+ sessions))))
+
+(defun mu--cider-load-buffer (session)
+ "Load the current buffer according to SESSION."
+ (if session
+ (let ((system (sesman--system))
+ (buf (current-buffer)))
+ (sesman--clear-links)
+ (sesman-link-session system session 'buffer buf)
+ (cider-load-buffer buf))
+ (message "No CIDER REPL available")))
+
+(defun mu-cider-load-clj-buffer ()
+ "Load the current Clojure buffer."
+ (interactive)
+ (mu--cider-load-buffer (mu--cider-session-by-type 'clj)))
+
+(defun mu-cider-load-cljc-buffer ()
+ "Load the current ClojureC buffer."
+ (interactive)
+ (let ((clj-session (mu--cider-session-by-type 'clj))
+ (cljs-session (mu--cider-session-by-type 'cljs)))
+ (if (and (null clj-session)
+ (null cljs-session))
+ (message "No CIDER REPL available")
+ (when clj-session
+ (mu--cider-load-buffer clj-session))
+ (when cljs-session
+ (mu--cider-load-buffer cljs-session)))))
+
+(defun mu-cider-load-cljs-buffer ()
+ "Load the current ClojureScript buffer."
+ (interactive)
+ (mu--cider-load-buffer (mu--cider-session-by-type 'cljs)))
+Just like for C-c C-z, C-c C-k is now bound to these commands according to the
+mode map. For the sake of completeness, I have also disabled both C-c C-k and
+C-c C-z in cider-mode-map in order to avoid any kind of overshadowing by CIDER.
Note that this approach works well with my intended CIDER usage. It may not be +what you are looking for if you are experiencing the same problems with REPL +switching and buffer loading. Still, I have been using these commands for a +while now and I am happy with them. CIDER has become my trusted Clojure IDE +again.
+ +
+ 
+
+
+ Teamwork
+MonkeyUser 16 10 2020
+
+
+
+
+ Congreso esLibre y PyConES 2020
+República Web 10 10 2020
+Dedicamos la mayor parte del episodio a hablar sobre el Congreso esLibre 2020 celebrado el pasado mes de septiembre. La edición de esLibre de este año se celebró finalmente online, transmitiendo desde la Universidad Rey Juan Carlos gracias al interés mostrado por su Oficina de Conocimiento y Cultura Libres (OfiLibre de la URJC).
+ + + +David Vaquero tuvo la oportunidad de participar como ponente y en este episodio nos acerca la organización de este evento y sus promotores, las soluciones tecnológicas que utilizaron, el proceso de selección abierto de las candidaturas y también los fines que se persiguen conseguir. El Congreso esLibre 2020 reunió en dos jornadas, una variada selección de charlas y conferencias alrededor de varias pistas relacionadas con el software libre.
+ + + +También hacemos mención del evento 24H24L un evento online de 24 horas de duración que constará de 24 audios sobre el uso de GNU / Linux, experiencias profesionales y personales alrededor de seis categorías: Redes, Empresa, Desarrollo, Hardware, Multimedia y GNU/Linux.
+ + + +En la segunda parte Andros Fenollosa nos contará su experiencia participando como organizador y ponente en la edición online de la conferencia sobre Python en España PyConES2020 Pandemic Edition. Andros ofreció una charla sobre introducción a la programación funcional, que además colgamos como episodio bonus en el feed del podcast.
+ + + +Por último, aportamos varios recursos y enlaces recomendados en la sección Radar del episodio.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+ 
+
+
+ Reverse Turing Test
+MonkeyUser 09 10 2020
+
+
+
+
+ Introducción a la Programación Funcional con Python
+República Web 05 10 2020
+Como episodio bonus os dejamos el audio de la charla que ofreció Andros Fenollosa en la Pycon España 2020, que este año se realizó de manera virtual. En esta charla Andros ofrece una introducción muy interesante para conocer en qué consiste la programación funcional y en qué se diferencia de otros tipos de programación (imperativa y orientada a objetos).
+ + + +En la web de la PyCon están colgadas todas las charlas y se pueden seguir desde su canal de YouTube.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Full-Bleed Layout Using CSS Grid
+Josh Comeau's blog 05 10 2020
+
+
+
+
+ En qué ando: desescalando
+Onda Hostil 04 10 2020
+
+
+ Meme generator in emacs
+(ノ°Д°）ノ︵ ┻━┻ 04 10 2020
+
+
+ Getting started with Tsung
+(ノ°Д°）ノ︵ ┻━┻ 03 10 2020
+
+ 
+
+
+ Getting started with Tsung
+(ノ°Д°）ノ︵ ┻━┻ 03 10 2020
+
+
++What is tsung +
+
+
++Tsung is a load testing tool written in erlang, it allow us to perform load testing for web applications, databases, etc. Or as its website says:
+++Tsung (formerly IDX-Tsunami) is a distributed load testing tool. It is protocol-independent and can currently be used to stress HTTP, WebDAV, SOAP, PostgreSQL, MySQL, AMQP, MQTT, LDAP and Jabber/XMPP servers.
+
+More info is available in its web page http://tsung.erlang-projects.org/user_manual/
+
+In this post we'll cover how to test a web application and at the time of writing this the available version of tsung is 1.7.0.
+
++Installation +
+
+
++DISCLAIMER: All the steps described here are for macOS, there shouldn't be many differences for a linux system.
+
+Tsung is available on homebrew so we can install it using brew install tsung, also we'll need perl for charts generation so we can install it with brew install perl as well.
+In order to generate charts correctly we need to install a required dependency, we have to execute cpan template and we're almost ready to go
+A last step is change the perl script a little bit, in macOS is located in /usr/local/lib/tsung/bin/tsung_stats.pl. We first need to change its permissions so we can be able to edit it, we can execute chmod 755 =/usr/local/lib/tsung/bin/tsung_stats.pl. Now we can apply the following change:
+
+
+-#!/usr/bin/perl -w
++#!/usr/local/bin/perl -w
+
+As you can see we changed the location of the perl installation, this was the easiest way I found to make it work properly without the need to make some other changes to perl installation.
+
++Demo project +
+
+
+
+
+
+
+We're going to use this example project for our tests. We can follow the instructions described in its README.md file.
+This project have the following urls:
+| route | +description | +method | +content type | +
|---|---|---|---|
| / | +index page with an html message | +GET | +text/html | +
| /ping | +respond a pong message | +GET | +text/plain | +
| /users | +respond with a list of users in json | +GET | +application/json | +
| /users | +allow to create a new user | +POST | +application/json | +
+We're going to write test for each of this routes.
+
+
++Defining load tests +
+
+
+
+Tsung load tests are defined in xml, in these xml files we can define the behaviour of the test, how many clients we want to execute, define the the endpoints to be used and so on.
+tsung comes with some examples included, in macOS we can find them in /usr/share/doc/tsung/examples and use them as a base for creating new tests.
+This a simplified version of the example http_simple.xml example included in the installation folder, let's create a file called demo.xml and put this content on it:
+
+
+<?xml version="1.0"?>
+<!DOCTYPE tsung SYSTEM "/usr/local/Cellar/tsung/1.7.0/share/tsung/tsung-1.0.dtd">
+<tsung loglevel="notice" version="1.0">
+ <clients>
+ <client host="localhost" use_controller_vm="true"/>
+ </clients>
+
+ <servers>
+ <server host="localhost" port="4000" type="tcp"></server>
+ </servers>
+
+ <load>
+ <arrivalphase phase="1" duration="10" unit="minute">
+ <users arrivalrate="10" unit="second"></users>
+ </arrivalphase>
+ <arrivalphase phase="2" duration="5" unit="minute">
+ <users arrivalrate="20" unit="second"></users>
+ </arrivalphase>
+ </load>
+
+ <sessions>
+ <session name="http-example" probability="100" type="ts_http">
+ <request> <http url="/" method="GET" version="1.1"></http> </request>
+ <request> <http url="/ping" method="GET" version="1.1"></http> </request>
+ <request> <http url="/users" method="GET" version="1.1"></http> </request>
+ <request> <http url="/users" method="POST" contents_from_file="payload.json" content_type="application/json" version="1.1"></http> </request>
+ </session>
+ </sessions>
+</tsung>
+Note that the second line is pointed to a path inside the tsung installation folder, this can be changed, the tsung-1.0.dtd is available in its web page http://tsung.erlang-projects.org/user_manual/dtd.html.
+
+
+<!DOCTYPE tsung SYSTEM "/usr/local/Cellar/tsung/1.7.0/share/tsung/tsung-1.0.dtd">+Let's explain a little bit about the test sections:
+
+
++Client setup +
+
+
+
+Tsung is a distributed testing tool so we can execute the client in different hosts, for now we'll be executing the client in our machine so we can define the client in localhost:
+
+
+<clients>
+ <client host="localhost" use_controller_vm="true"/>
+</clients>
+
++Server setup +
+
+
+
+This is the server who will be serving the incoming requests from tsung, in this case is the same machine and listening at port 4000 using a TCP connection, in a proper test it should a separate machine.
+
+
+<servers>
+ <server host="localhost" port="4000" type="tcp"></server>
+</servers>
+
++Load behaviour +
+
+
+
+We can define how the test load will behave, in this case we're configuring tsung to have 2 phases:
-
+
-
+
The first phase will run for 10 minutes and create 10 users every second.
+
+ -
+
The second phase will run for 5 minutes and create 20 users every second.
+
+
+
+
+<load>
+ <arrivalphase phase="1" duration="10" unit="minute">
+ <users arrivalrate="10" unit="second"></users>
+ </arrivalphase>
+
+ <arrivalphase phase="2" duration="10" unit="minute">
+ <users arrivalrate="20" unit="second"></users>
+ </arrivalphase>
+</load>+For more info about the load configuration we can check http://tsung.erlang-projects.org/user_manual/conf-load.html
+
+
++HTTP requests +
+
+
++Now we can define what endpoints we're going to test, we can define the url, method used and some other properties that can be found in http://tsung.erlang-projects.org/user_manual/conf-sessions.html#http.
++In this case we're defining the 4 routes from our example project:
+
+
+
+<sessions>
+ <session name="http-example" probability="100" type="ts_http">
+ <request> <http url="/" method="GET" version="1.1"></http> </request>
+ <request> <http url="/ping" method="GET" version="1.1"></http> </request>
+ <request> <http url="/users" method="GET" version="1.1"></http> </request>
+ <request> <http url="/users" method="POST" contents_from_file="payload.json" content_type="application/json" version="1.1"></http> </request>
+ </session>
+</sessions>
+Note that in the case of the POST request we're defining a contents_from_file property, this allow us to load the body of the request from an external file, we can define it in the same test but it's easier to have a separate file, the content of the payload.json if the following:
+
+
+{
+ "name": "tsung",
+ "email": "demo@demo.com"
+}
+This file needs to be in the same folder as demo.xml
+
++Running the load tests +
+
+
+
+Now we have all the pieces on place so we can execute our tests, we should be in the folder where we create our demo.xml and run the following command:
+
+
+tsung -f demo.xml start+That should returns something like this:
+
+
+
+Starting Tsung
+Log directory is: /Users/erick/.tsung/log/20201004-1229
+For each execution tsung create a folder under ~/.tsung/log/ where all the data generated by the tests will be saved, tsung also has a embedded web server where we can see the results of the tests, by default it will run on http://localhost:8091/
+
++Reporting +
+
+
+
+We can see live reporting in the service running at http://localhost:8091/ or we can see more detailed data using the tsung_stats.pl script.
+
++Dynamic reporting +
+
+
++When we enter to http://localhost:8091/ we can see:
+-
+
-
+
A status page
+
+ -
+
A report page which shows stats about the load testing
+
+ -
+
A charts page
+
+ -
+
A logs page which shows all the generated log files
+
+
+
++Status page +
+
+
++We can see the status of the running tests:
+
+
+
++Reports page +
+
+
++We can see stats about the connection time, response times, OS resources usage and so on.
+
+
+
++Charts page +
+
+
++This could be the most interesting one, we can see pretty good charts about the behave of the service that we're testing, it has the following sections:
+-
+
-
+
Response time
+
+ -
+
Throughput
+
+ -
+
Simultaneous users
+
+ -
+
Server OS monitoring
+
+ -
+
HTTP return code Status (rate)
+
+
+
++Static reporting +
+
+
+
+Once we finish the tests we can go into the log folder, ~.tsung/log/20201004-1229 in this case, and generate more detailed charts, see CSVs with all the resulted data and more.
+To generate the chart we have to run the following command inside our log folder
+
+
+
+/usr/local/lib/tsung/bin/tsung_stats.pl+This will generate a few new folders inside of it:
+-
+
-
+
+csv_data: a list ofCSVfiles with all the data to be processed in some external tool likeRor ajupyter notebookfor example
+ -
+
+images: a set of more detailed charts
+
For example in this chart we can see the numbers of users vs the time, and as we can see the quantity was increased after 10 minutes, just like we defined in the config file.
+
+
+
+
+ +Final thoughts +
+
+
+
+tsung can be used to test not only http services, it supports sql databases, websocket protocol and many more protocols, so we can use it to perform load test for many parts of our application and because it is based on plain texts configuration files we can version them to keep track of the tests we perform along the time.
+
+ September 2020 Monthly Update
+News on Clojurists Together 03 10 2020
+
+ 
+
+
+ Ahead of its time
+MonkeyUser 29 09 2020
+
+
+ Building a Modern-Day Hit Counter
+Josh Comeau's blog 28 09 2020
+
+
+ Ten books which I read this year
+Isaak’s Blog 27 09 2020
+
+
+
+
+ Hay dos cosas inevitables: la muerte y los formularios
+República Web 26 09 2020
+Los formularios nos acompañan en la mayoría de nuestros proyectos web. Los desarrolladores se afanan en que sus formularios no contengan errores y que reciban la información correcta. También deben asegurarse que se protege a la aplicación, evitando la introducción de datos maliciosos que comprometan la integridad de la aplicación.
+ + + +También hay un trabajo de interacción y diseño muy importante. Los usuarios deben ser capaces de interactuar con nuestros formularios de una forma precisa y agradable. Todos queremos formularios intuitivos y fáciles de usar, pero huimos de los formularios largos y confusos. Los diseñadores y el equipo de marketing deben ser capaces de generar formularios que consigan los objetivos que se han propuesto con el sitio web.
+ + + +En este episodio hablamos sobre los formularios y lo que supone su diseño y operativa. Intentaremos tratar algunos de los aspectos esenciales que tenemos que tener en cuenta para trabajar con ellos y el reto que supone crearlos y mantenerlos.
+ + + +Entre las cuestiones que tratamos:
+ + + +- ¿Qué tenemos que tener en cuenta a la hora de diseñar un formulario? +
- ¿Qué tenemos que tener en cuenta a la hora de programar un formulario? + +
- Servicios y software dedicado a gestionar formularios.
En la segunda parte del episodio damos resultados de la última encuesta que hemos realizado sobre herramientas para gestionar control de versiones y en la última sección, Radar con enlaces y herramientas de interés.
+ + + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Updated Debian 10: 10.6 released
+Debian News 26 09 2020
+buster). +This point release mainly adds corrections for security issues, +along with a few adjustments for serious problems. Security advisories +have already been published separately and are referenced where available. + +
+
+ Composing queries with Mito, or doing without Django lazy querysets and Q objects
+Lisp journey 24 09 2020
+When I didn’t know Lisp at all, I skimmed at CLSQL’s and Mito’s
+documentation and I didn’t find a mention of “lazy”, “querysets” (a
+Django term!) nor a mention of any means to compose queries. I had no
+idea how I would replace querysets, F and Q objects and the many
+functions for DB queries that were being added into newer Django
+versions. I concluded that the Lisp ecosystem was lagging behind.
Table of Contents
+ + + + + +Then I began to understand. And today I got the chance to rewrite a
+Django query involving querysets and Q objects, using regular
+Lisp. All you have to know is back-quote and comma.
We implement a simple search into a DB. The user enters one or more
+words and we search against the title and the authors fields. We
+want to match all words, but each can be either in the title, either
+in the authors field.
Considering we have two products:
+ +1 - The Lisp Condition System - phoe
+2 - Implementing a blockchain in Lisp - F. Drummer
+then searching for “lisp cond” must return one result. DWIM.
+ +In Python, we must use Q objects to “OR” the terms with | (you can’t use | without Q):
products = firstquery()
+for word in words:
+ products = products.objects.filter(Q(title__icontains=word) |
+ Q(authors__name__icontains=word))\
+ .distinct()
+The promise of filter is to be lazy, so when we chain them the ORM
+ constructs one single SQL query.
So what does this query yield as SQL? Funnily, I didn’t find a +built-in way to get the generated SQL and I had to use a third-party +library. Mmh, I could use special logging. The fact is, we are far +from SQL here (and, with the experience, it is NOT a good thing).
+ +It looks like this (searching “hommes femmes” in our test DB):
+ + SELECT DISTINCT ... FROM "product" LEFT OUTER JOIN ...
+ WHERE
+ (("product"."title" LIKE %hommes% ESCAPE '\'
+ OR "author"."name" LIKE %hommes% ESCAPE '\')
+ AND
+ ("product"."title" LIKE %femmes% ESCAPE '\'
+ OR T5."name" LIKE %femmes% ESCAPE '\'))
+ ORDER BY "product"."created" DESC
+ LIMIT 3
+Does that look complicated? Does that need alien “Q objects”?! It’s just a AND around two OR:
+ + title like keyword 1 OR author like keyword 1
+AND
+ title like keyword 2 OR author like keyword 2
+Mito is the high-level library, and we compose queries with SXQL. I +already had a little query that worked with one keyword:
+ +(defun find-product (&key query (order :asc))
+ (mito:select-dao 'product
+ (when query
+ (sxql:where (:or (:like :title (str:concat "%" query "%"))
+ (:like :authors (str:concat "%" query "%")))))
+ (sxql:order-by `(,order :created-at))))
+If :query is given, we filter the search. If not, the when is not executed and we return all products.
So what we need to do is iterate over the keywords, produce as many OR +and wrap them with a AND. We want something like that (we can try in the REPL):
+ +(:AND
+ (:OR (:LIKE :TITLE "%word1%")
+ (:LIKE :AUTHORS "%word1%"))
+ (:OR (:LIKE :TITLE "%word2%")
+ (:LIKE :AUTHORS "%word2%")))
+So:
+ +The solution
+ +(sxql:where
+ `(:and ;; <-- backquote
+ ,@(loop for word in (str:words query) ;; <-- comma-splice
+ :collect `(:or (:like :title ,(str:concat "%" word "%")) ;; <-- backquote, comma
+ (:like :authors ,(str:concat "%" word "%"))))))
+(using (ql:quickload "str"))
Pay attention to ,@ (comma-splice). Without it, we get a bad level
+of nesting and two parenthesis before the :OR. We would get a list of
+clauses, instead of each clause individually. You can try in the REPL.
Note: if you are uneasy with back-quote and comma, see: https://lispcookbook.github.io/cl-cookbook/macros.html
+ +Last words
+ +Django’s filter is similar to using a
+When,
+which we were already using on the Lisp side without knowing it was
+anything special. “Q objects” are easy to replace. So, Python and
+Django might be easy to getting started with (or it is your feeling,
+because you must learn the special syntax and its limitations, I bet
+you had some “WTF?!” moments), but comes a time when your application
+grows that you pay the price of being far from SQL (not counting the
+maintenance cost).
With Mito and SXQL, it’s all regular Lisp, we are closer to the metal, +the only limitation being to know the language, and a bit of SQL.
+ +So we have a great example of why some Common Lisp libraries have a +surprisingly low number of commits. You know, that little voice in +your head that wonders if a library is finished or active. The author +might not need to develop feature X, thanks to Lisp’s +expressiveness. Likewise, many questions don’t need to be asked or +upvoted on Stack-Overflow. Though I should have asked years ago.
+ ++ +
-
+
- getting started with a DB: https://lispcookbook.github.io/cl-cookbook/databases.html +
- more DB choices: https://github.com/CodyReichert/awesome-cl#database +
+ +
+You like what I'm doing?
+
+ +
+
+
+
+ + +
+
+
+ 
+
+
+ Project Setup
+MonkeyUser 22 09 2020
+
+
+ A Friendly Introduction to Spring Physics
+Josh Comeau's blog 21 09 2020
+
+
+
+
+ Heliblocks para WordPress y CSS moderno con Jesús Olazagoitia
+República Web 20 09 2020
+Para este episodio redondo 150 contamos con la compañía del colega desarrollador web Jesús Olazagoitia, todo un especialista en CSS y en tecnologías frontend. Jesús es organizador del meetup WordPress Logroño y realiza desarrollos modernos en WordPress basados en frameworks JavaScript.
+ + + +Recientemente Jesús lanzó un original proyecto personal llamado Heliblocks. Se trata de un plugin para WordPress que te permite construir y reutilizar bloques o snippets de código independientes como si fueran bloques de Gutenberg. Con Heliblocks es posible crear bloques sólo con HTML y CSS, aprovechando las potentes funcionalidades de la edición de Gutenberg.
+ + + +Con Jesús hablamos de los motivos que le han llevado a desarrollar este proyecto y las soluciones que trata de abordar. Hablamos de su integración con Gutenberg, las posibilidades que ofrece como marketplace de snippers y también la trayectoria futura del proyecto.
+ + + +Aprovechando su experiencia con CSS para hablar sobre variables CSS, soporte de navegadores para propiedades modernas de CSS. También hablamos de lo que suponen los Headless CMS dentro de entornos CMS como WordPress, con tecnologías como Frontity.
+ + + +Por último con Jesús hablamos sobre otro proyecto que tiene para realizar un sistema de diseño y además sobre el futuro de WordPress.
+ + + +En la parte final del podcast volvemos con la sección de Radar, con una aportación variada de herramientas, enlaces y recursos de gran interés para el desarrollo web y creación de contenidos en internet.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ Simple Anomaly Detection Using Plain SQL
+Haki Benita 20 09 2020
+Many developers think that having a critical bug in their code is the worse thing that can happen. Well, there is something much worst than that: Having a critical bug in your code and not knowing about it! Using some high school level statistics and a fair knowledge of SQL, I implemented a very simple anomaly detection system.
+
+
+
+
+ Estado del ecosistema PHP con Jesús Amieiro
+República Web 12 09 2020
+Tras el parón veraniego, retomamos los episodios del podcast para hablar sobre PHP. Para ello tenemos como invitado a Jesús Amieiro, un gran divulgador del lenguaje, a través de su newsletter / podcast La Semana PHP. Jesús es ingeniero de telecomunicación y desarrollador web, especialista en entornos PHP. Jesús además de su trabajo como director técnico en proyectos tecnológicos, es un gran conocedor del ecosistema PHP y participa en numerosos eventos como WordCamps y meetups.
+ + + +Por si fuera Jesús saca tiempo para difundir oportunidades de empleo en un canal de Telegram, con ofertas de trabajo en el entorno PHP y reciente ha estrenado la versión podcast de su newsletter.
+ + + +Entre las cuestiones que comentamos junto a Jesús Amieiro:
+ + + +- Novedades más destacables de la nueva versión PHP 8.
- Repaso a la actualidad de los principales frameworks y gestores de contenido.
- Perfil profesional detectado a través de su canal de Telegram.
- El trabajo con la newsletter y el podcast La Semana PHP.
- Futuro del lenguaje y recursos interesantes.
En definitiva una charla muy completa con un entusiasta del ecosistema PHP, que nos deja con ganas de un nuevo episodio para tratar más tecnologías.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+ 
+
+
+ Adjustment
+MonkeyUser 08 09 2020
+
+
+ August 2020 Monthly Update
+News on Clojurists Together 07 09 2020
+
+ 
+
+
+ New Hire
+MonkeyUser 31 08 2020
+
+
+ DebConf20 online closes
+Debian News 30 08 2020
+
+
+ Q3 2020 Funding Announcement
+News on Clojurists Together 28 08 2020
+
+
+ July 2020 Monthly Update
+News on Clojurists Together 27 08 2020
+
+ 
+
+
+ Wish 'Granted'
+MonkeyUser 25 08 2020
+
+
+ Python libraries to make your code readable, reliable and maintainable
+Isaak’s Blog 24 08 2020
+
+ 
+
+
+ Code Freeze
+MonkeyUser 18 08 2020
+
+
+ Remote teams and the half-life of social capital
+James Sinclair 11 08 2020
+
+ 
+
+
+ Regex Explained
+MonkeyUser 11 08 2020
+
+ 
+
+
+ Duplicates
+MonkeyUser 04 08 2020
+
+
+ The World’s Sneakiest Route Change
+Josh Comeau's blog 31 07 2020
+
+ 
+
+
+ Art Overflow
+MonkeyUser 28 07 2020
+
+
+ Some SQL Tricks of an Application DBA
+Haki Benita 26 07 2020
+Some tips and misconceptions about database development I gathered along the way.
+
+
+ Cognitect Joins Nubank!
+Clojure News 23 07 2020
+
+
+
+ We are thrilled to announce that Cognitect is joining the Nubank family of companies. This is the next step in a long relationship, and opens new opportunities for Clojure worldwide. Please read the full story over on the Cognitect +blog.
+
+
+ Things to keep in mind when contributing to a software project
+(ノ°Д°）ノ︵ ┻━┻ 21 07 2020
+
+
+ Things to keep in mind when contributing to a software project
+(ノ°Д°）ノ︵ ┻━┻ 21 07 2020
++These are some are thoughts to keep in mind when we're contributing to a software project.
+
+
++Know your tools +
+
+
+
+Git is maybe the most extended tool to manage version control in software and as a daily tool we should invest some time in knowing how to use it "properly".
+
++Configure your name and email properly +
+
+
+
+This helps to identify who make a change while we're browsing git log history. Don't use initials or nicknames, in a few months or maybe years eventually you will be looking at the git log and if you see something like this Author: XYZ <xyz@some-random-provider.com> you won't have a clue who make that change. We can setup this information with:
+
+
+git config --global user.name "name and last name"
+git config --global user.email "work-or-personal-email"
+We can use it without --global to make these changes only in the current repository.
+
++Commits should have a title and a body +
+
+
++A easy to remember "rule" could be "Put what you did in the title and why you did it in the body". Memory is fragile and it could sound useless now but in a few months when you'll be looking at the log and see a commit and wanted to know why some change was made and the commit message just says "Fix some error" you probably will get angry with your past self.
++There is an article that explains this so much better than me, you could read it at https://chris.beams.io/posts/git-commit/
++An easy "hack" to force yourself to follow this is create a "commit template", it will be used when you make a commit and it will remind you about this rule. An example one could be:
+
+
+
+# If applied, this commit will...
+
+# Explain why this change is being made
+
+# Provide links to any relevant tickets, articles or other resources+These lines are comments and won't be added to the final commit message.
+
+Put this in ~/.git_commit_message.txt and then configure you ~/.gitconfig like this:
+
+
+[commit]
+ template = ~/.git_commit_message.txt
+After configuring this every time you make a commit the content of ~/.git_commit_message.txt will be filled into the commit message so that will remind you how to write a proper message. The editor/IDE you use to write a message will recognize this file.
+
++Review what your staging +
+
+
+++Friends don't let friend use
+git add .
+The tool you use to stage changes and then commit should allow you to stage chunks of code one by one. This way you can review what are you adding. You don't want to commit those debug messages or commented code that you were using while your working on the project. Or even worse you definitively don't want to commit credentials files.
+
+Also if you like to use git from the terminal, you can use git add -p to use an interactive mode, this will go through all the unstaged changes and will ask you one by one if you want to add them.
+
++Conventions and consistency +
+
+
+
+Most projects already have a CONTRIBUTING.md file. This file has some guidelines and conventions used in the project. Take your time to read and understand it. Those guidelines exist to keep consistency across the project. They're not fixed rules and of course they could be improved but always discuss that with your team.
+
++Submitting a pull request +
+
+
++OK you're done with a feature/fix/whatever your were working on. It's time to submit a pull request. This is a simple checklist that could be followed:
+-
+
-
+
Make sure your changes are in sync with the latest changes in
+upstream. Maybe you're been working on something for a few days but some new changes were made to the project since the last sync.
+ -
+
Make sure you ran the whole test suite, run checkers and others pre-commit workflow that your project have.
+
+ -
+
Check the commits you've made. Maybe you can clean a little bit the log, remove some
+WIPcommits or improving some messages.
+
After you submit the pull request be your first reviewer before asking for more reviews. Once the pull request is created go to the pull request page on Github/Gitlab/etc and make a last check of your changes. Then assign the reviewers.
++Use tags, this way you are adding extra information that will help to understand and categorize the pull request, by looking at the tags we can know if the pull request is a fix, improvement, documentation, etc.
+
+Link your pull request with an issue. Github|Gitlab|etc have a nice feature to link pull requests with issues, for example if you're fixing a reported issue with number 10 add fixes #10 in the pull request description and this will link it to that issue, this way we can have traceability about the work done and the issues reported.
+Improve pull request description, when you open a pull request Github|Gitlab|etc takes the first commit title and message and use them as title and description for the pull request so if we have made good commit messages most of the work is already done. Make review process a little easier by explaining what have you done. Maybe link another issues in different projects or bug reports related the changes you have made. Some extra context is always welcome :)
+
+
+
+ +Code review +
+
+
++Keep in mind that comments made in your pull request are made about the code and not about you.
++Don't take a comment as a fact that should be followed immediately, reviewers can make mistakes too, if you think some suggestion doesn't apply, explain your point of view and try to understand what is the reason behind that suggestion.
++Don't make changes just to make reviewers happy and get your pull request merged. A code review is an excellent opportunity to get more knowledge about the project and to learn more about the code review process itself.
++If someone rewrite or delete some code that you wrote it isn't mean necessary is was "bad code" or something like that, maybe the requirement was different back then. Code has to evolve and at the end what matters the most is that the application does what is supposed to do. Also in some cases you'll be the one who is refactoring or fixing your own code after a while it was made ;)
+
+ 
+
+
+ Side Project Showcase
+MonkeyUser 21 07 2020
+
+
+ How are Lisp REPLs different from Python or Ruby REPLs ? (Hackernews, 2020)
+Lisp journey 14 07 2020
+Mikelevins, https://news.ycombinator.com/item?id=23811382, July 2020
+ +(some more comments on https://www.reddit.com/r/lisp/comments/hqesvp/explaining_the_advantages_of_the_repl/)
+ +(on terminology: we should maybe call Python’s “REPL” a shell, and put emphasis on image-based development, instead of only saying REPL, for Lisp)
+ ++ +
I’ve answered similar questions several times over the past few years, but I don’t mind repeating myself. It offers me a glimmer of hope that my preferred way of working may not fade away, after all.
+ +Consider the standard Common Lisp generic function UPDATE-INSTANCE-FOR-REDEFINED-CLASS (http://clhs.lisp.se/Body/f_upda_1.htm). It reinitializes an object when Lisp detects that the object’s class definition has changed.
Ask yourself this: who would call such a function? Why would anyone ever invent it? Not only did someone invent it, a committee of some of the world’s smartest and most experienced Lisp programmers wrote it into the ANSI standard for the language. What were they up to?
+ +UPDATE-INSTANCE-FOR-REDEFINED-CLASS is not a weird anomaly; it’s part of a carefully-considered set of features and protocols designed to support a specific style of programming. The Lisp runtime calls it for you automatically when it touches an object whose class definition has changed.
If you’ve defined a method specialized for it, then Lisp executes that method to rebuild the touched instance as if it had originally been instantiated from the class’s new definition, and then your program goes its merry way. If you didn’t specialize UPDATE-INSTANCE-FOR-REDEFINED-CLASS for this case, then the Lisp drops you into a breakloop.
A breakloop is an interactive repl with full access to all of the runtime’s memory and all of the language’s features, including visibility into the whole call stack that landed you in the breakloop. You can wander up and down the call stack, inspect anything in the runtime, edit bindings, redefine types and functions, and resume execution either at the point of control where the breakloop started, or at any other point for which the breakloop exposes a restart.
+ +UPDATE-INSTANCE-FOR-REDEFINED-CLASS is not the weird fever dream of a confused eccentric. It’s part of a purposeful system design intended to support a style of programming in which you build a program by interacting with a live runtime and teach it, interaction-by-interaction, how to be the program you want, while it runs.
It’s a particular example of a general approach to programming best exemplified by these old systems. That general approach is the answer to your question: “Can someone knowledgeable explain how are lisp REPLs different from Python / Ruby REPLs? What is the differentiating point of REPL driven development?”
+ +The differentiating point is that the entire language and system is thoughtfully designed from the ground up with the assumption that you’re going to be changing your work in progress while it runs, and that you should be able to change absolutely anything about it as it runs and have a reasonable expectation that it will continue to work while you do it.
+ +I like to call this style of programming “programming as teaching”, and distinguish it from the much more widespread “programming as carpentry”, in which the programmer is, metaphorically speaking, at a workbench banging together artifacts and assembling them to see how they turn out.
+ +To be clear, I do not claim that the teaching approach is objectively better than the carpentry approach. I claim only that I, personally, am happier and measurably more productive using the teaching approach. I know that some other programmers report the same thing, and I suspect that if the teaching style of programming were more widely known, then there would be more programmers who prefer it.
+ +There are several sibling comments that assert that any language can be made to support repl-driven programming, or that offer various languages and systems as examples of repl-driven programming. I’m sure that’s all true, for some relatively restricted version of repl-driven programming, but the gold standard in repl-driven programming is programming as teaching in the style of old-fashioned Lisp and Smalltalk systems. These old systems offer amenities that the younger alternatives touted here do not match. I want more people to be aware of what they’re missing.
+ +Starting in the 1980s, I grew accustomed to systems that could start from cold in about a second, presenting to me a complete interactive development environment with all tools preloaded and ready to work, with the whole dynamic environment of my work in progress in the same state it was in the last time I was working with it. Moreover, I was accustomed to being able to take a single file from one machine to another to reproduce that same whole working environment equally quickly and easily on the new machine.
+ +I could save the entire dynamic state of the running system to an image file, a serialized version of the running system’s memory. I could later start up the system with that image file and be exactly where I was when I saved the image, right down to the positions and contents of all the open windows. I could save an image showing some bug or some strange behavior and give it to a colleague so that they could see it, too, and interact with the restored dynamic state to debug it.
+ +I enjoyed comprehensive whole-system reflection that enabled me to view and edit absolutely everything in the running system while it ran. I could inspect absolutely everything, including the development environment and all its tools, interactively change any variable or field value, redefine any type or function, and continue to work with the changed system without stopping and restarting. (Obviously, if I made a bad change I might break the system, but remember, I could kill it and get back to where I started in a second or so).
+ +I could start some process running–perhaps a 3D animation in a game, or a discrete-event simulation, or whatever–and change any values or definitions I liked to see what changed in the running process, without stopping the process to rebuild. For example, I could tell a rotating copper cube to become a glass icosahedron and reasonably expect to see my changes immediately reflected in the running program. This property is invaluable not only in games, simulations, and any kind of work with a visual-design component, but also in any kind of exploratory programming, where you’re constructing data structures and evaluating expressions interactively to test your ideas.
+ +Similarly, I could build some speculative data structure to explore an idea, and define some functions to operate on it. I could evaluate those expressions to see their results or to change the example structure. I could inspect the structure interactively and edit it in place if I think something different would work better. If I think a problem is caused by some structure or value in it, I could use the inspector to change it and see. If I thought one my my functions was doing something I didn’t expect, I could insert a call to break, to activate a repl from inside the function call that would enable me to inspect and edit the data structure, redefine the function, and continue from there.
+ +Anything the development system could do, I could do by typing an expression into the repl. As an example, nowadays you can still rebuild the whole Clozure Common Lisp environment from the ground up by typing (rebuild-ccl :full t).
+ +The point is not that I would want to rebuld my Lisp from the repl all the time. The point is that the repl doesn’t impose any aribtrary boundaries on what I can do. If the language and development environment can do it, I can do it from the repl. This is one of the properties that distinguishes the whole-system interactive design of these old tools from the more limited repls offered by newer ones. In pretty much every repl I’ve used other than old-style Lisps and Smalltalks I’m all the time stumbling over things you can’t do from the repl.
+ +I mentioned breakloops above. Their absence in younger languages and tools seem to me like some sort of sin, like we’re tragically abandoning some of the best lessons of the past. Few newer development systems have them, but they’re incredibly useful–at least if the language runtime is designed to properly support interactive programming.
+ +A breakloop is a repl with all of the same affordances of the normal repl, but extended with all of the dynamic state of the control path that invoked the breakloop. If an error or an intentional call to break triggers a breakloop somewhere deep in a stack of recursive function calls, you get a repl that can see every frame of that stack, and every variable and value lexically accessible from it. You can browse all of that whole, change values, and redefine functions and types. You can resume execution at your leisure, and any changes you made in the breakloop will be visible in the resumed computation just as if that’s how things were originally.
+ +Proper breakloops don’t just improve error messages; they replace them wholesale with an entire species of programming that lays the whole dynamic state of the system out on the table for you to examine and modify while the program continues to run.
+ +Moreover, everything I just described about breakloops can also be automated. These old systems provide not only interactive tools for rummaging through the dynamic state of a suspended computation, but also APIs for handling them under program control. For example, you can wrap an arbitrary function call in condition handlers that will either drop you into a breakloop and enable you to vivisect the program state, or consult the dynamic state and compute which of several restarts to activate in order to transfer control to a path of your choosing.
+ +I’m banging up against HN’s length limit, but the above, I hope, goes some way toward answering to your question.
+ +
+
+
+ 13% of my website visitors block Google Analytics
+Marko Saric 13 07 2020
+
+
+
+
+ Historias del Backend con Antonio Pérez de Full Stack Podcast
+República Web 11 07 2020
+Vuelve nuestro amigo Antonio Pérez al podcast para otro episodio compartido con su programa Full Stack Podcast. Antonio ya nos acompañó allá por el episodio 78 en un programa titulado Ruby on Rails frente a Python. En ese episodio Antonio nos estuvo contando cosas muy interesantes sobre Ruby on Rails y para este episodio hemos preparado el contenido alrededor del perfil de backend.
+¿Qué habilidades clave debería tener un profesional del backend?
+Para Antonio Pérez, un desarrollador de backend debe tener un perfil muy completo con unas habilidades muy distintas: Una capacidad alta de abstracción, conocimientos de arquitectura web y un conocimiento amplio de bases de datos.
+Para Andros un backend debe tener la capacidad de leer y entender el contexto de lo que está realizando. Por eso es importante acudir a la documentación y a los manuales. Otro aspecto es entender que es normal que no se pueda saber de todo. Por último, Andros también coincide sobre la importancia de conocer de manera sólida las bases de datos.
+David Vaquero coincide en la necesidad de tener una base muy sólida del protocolo HTTP. También que el backend entienda bien los datos que está manejando y cómo se mueven. Y también vuelve a coincidir con la gestión de datos, caché y optimización. Por último David hace mención al conocimiento de API y al Server Side Rendering.
+Para finalizar Javier comenta que a menudo el perfil de backend se asocia al conocimiento de un lenguaje de programación. Otro aspecto a destacar es el conocimiento de la computación y los bases del sistema operativo, procesos, memoria y red.
++Gran parte de los proyectos backend que se están ejecutando implican tareas de mantenimiento, monitorización y mejora. Con independencia del lenguaje, el backend necesita mucha investigación y aprendizaje.
La importancia de la gestión de las bases de datos y la memoria caché
+Como comenta Antonio, el backend un última instancia es servir datos: cuando mayor conocimiento y eficacia en la capa de base de datos, mejor funciona la parte de backend. Conocer los motores de bases de datos, profundo conocimiento de SQL y conocer los ORM.
+Andros habla sobre lo básico de entender la gestión de bases de datos y pone como ejemplo la aplicación de Notion y lo fundamental que es optimizar en la capa de datos. También incidimos en el conocimiento de los básicos como programación orientada a objetos, computación y redes. Una recomendación que hacemos es el libro The Secret Life of Programs publicado por No Starch Press.
+Por último David destaca que el mundo de las bases de datos también incluye las tecnologías NoSQL y que hay que separar la teoría de base de datos con la práctica.
+Escribir sentencias SQL vs ORM
+Otro de los temas que han surgido en la conversación son los ORM vs la escritura de sentencias SQL. Antonio explica cómo en ciertas ocasiones escribir directamente las sentencias SQL resulta más productivo o eficaz que depender de un ORM. Antonio destaca Active Record de Rails como una herramienta flexible para trabajar con el acceso a datos. También hablamos brevemente algunos de los ORM más habituales.
+El back end es la parte más cercana a la lógica de negocio y por tanto debes tener un conocimiento muy preciso y amplio de cómo funciona un negocio a
+El papel del cloud en el backend y el serverless
+Hay espacio para comentar cómo está evolucionando la computación en el lado de servidor con los servicios en la nube y más específicamente con el serverless tipo AWS Lambda. Con todo, son tecnologías que tienen un espacio determinado y que conviven con diferentes opciones en el lado de servidor. Antonio nos detalla algún ejemplo donde puede encajar este tipo de tecnologías. Otro aspecto a tener en cuenta es la optimización de esas funciones sin servidor porque pueden salir más caras que una arquitectura convencional cliente/servidor.
+Tecnologías de backend a tener en el radar
+Antonio nos cuenta algunas tecnologías a tener muy en cuenta como la contenerización, micro-servicios, serverless, entornos elásticos en la nube y la asincronía. También reserva un espacio para hablar sobre el papel de JavaScript en el lado servidor y sus reservas con respecto a sus ventajas en materia de asincronía. Por último Antonio nos ha contado sus proyectos futuros, como una web de cursos de desarrollo, estudiando tecnologías como Data Science y NoSQL.
+ + + +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
Nos podéis encontrar en:
- Web: republicaweb.es
- Canal Telegram: t.me/republicaweb
- Grupo Telegram Malditos Webmasters
- Twitter: @republicawebes
- Facebook: https://www.facebook.com/republicaweb
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+
+
+ June 2020 Monthly Update
+News on Clojurists Together 09 07 2020
+
+
+ The idiomatic comparison in Python
+Isaak’s Blog 08 07 2020
+
+
+ Hack Keyboard Shortcuts Into Sites with a Custom Chrome Extension
+blog.karenying.com 07 07 2020
+
+
+
+
+ Las cheat sheets de Manz, aprendizaje y especialización en desarrollo web
+República Web 07 07 2020
+Nuestro episodio 147 con Manz se alargó tanto que se nos quedaban algunos temas pendientes que no queríamos perder. Por eso le planteamos a Manz un episodio adicional como bonus, dirigido a hablar sobre sus plantillas o chuletas (cheat sheets). Desde hace años Manz distribuye de manera gratuita estos útiles recursos para aprender desarrollo web.
+Manz nos cuenta el origen de estos recursos, cómo las diseña y el público que las consume. Manz publica estas plantillas bajo un modelo de donación, pero como descarga libre y gratuita.
+En esta conversación también surgen otros temas interesantes como son el papel del idioma inglés en los contenidos, el aprendizaje del desarrollo web y la especialización versus los perfiles generalistas en la profesión.
+Como hemos comentado en el podcast con la entrevista, esperamos poder compartir con Manz alguna episodio adicional para tratar más temas sobre diseño y desarrollo web.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+ Only 9% of visitors give GDPR consent to be tracked
+Marko Saric 06 07 2020
+
+
+ Thoughts about naming variables and methods
+Isaak’s Blog 06 07 2020
+
+
+ A teeny-tiny note about comments and dead code
+Isaak’s Blog 05 07 2020
+
+
+
+
+ Divulgación y aprendizaje de tecnologías Front-end con Manz
+República Web 04 07 2020
+En este episodio tenemos como invitado al divulgador Manz, autor del blog Emezeta y creador de la chuleta (o cheat sheet) HTML/CSS/Javascript más popular de la web. Actualmente Manz compagina su actividad de profesor en la Universidad de La Laguna (Tenerife) con otros proyectos profesionales. Man empezó como profesor en la Oficina de Software Libre impartiendo cursos de formación en temáticas relacionadas con el desarrollo, la programación web, front-end, back-end, cloud computing, marketing digital o temas relacionados con la tecnología de internet.
+Manz además mentoriza proyectos y startups en la Escuela de Organización Industrial. También colabora como formador y consultor en programas de emprendimiento de la Fundación INCYDE. Con él hablamos de JavaScript, Web Componentes, CSS, Shadow DOM, gestores de tareas y un montón de cosas interesantes relacionadas con el front-end.
+Entre las cuestiones planteadas con Manz:
+-
+
- Javascript-fatigue, ¿el Front-End es una carrera de fondo sin una meta definida? +
- ¿Qué son los Webcomponents? ¿Shadow DOM? ¿Son el futuro? Ejemplos prácticos. +
- CSS-in-JS, ¿estamos invadiendo territorios o creando naciones? +
- ¿Por qué necesitamos automatizadores? ¿En que se diferencian: Parcel / Webpack / Rollup / Gulp? +
Una interesantísima conversación con un divulgador y apasionado de las tecnologías web, con el que además dedicaremos un episodio bonus para contar su trabajo con las plantillas y sus cheat sheets de diferentes lenguajes.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ The beginning of the way
+Isaak’s Blog 04 07 2020
+
+
+ 50 Shades of Dark Mode Gray
+blog.karenying.com 03 07 2020
+
+
+ 404: React Page Not Found
+blog.karenying.com 02 07 2020
+
+
+ Annoy (or Impress) Your Coworkers with a Slack Bot From Scratch
+blog.karenying.com 29 06 2020
+
+
+ LOS RESIDUOS EN CANARIAS. LA CULTURA DEL USAR Y TIRAR. LOS MICROPLÁSTICOS
+Andanzas de una ambientóloga . . . 29 06 2020
+
+
+
+
+ Vivir la GPL o explotar GPL con José Conti
+República Web 29 06 2020
+En este podcast hemos tratado en alguna ocasión cuestiones relacionadas con el código abierto y la dificultad que conlleva vivir de los proyectos abiertos. En este programa volvemos con estas cuestiones y hemos invitado al desarrollador especialista en WordPress, José Conti para hablar sobre GPL, o la licencia pública general GNU. Recientemente José Conti publicó un sólido artículo titulado Vivir la GPL o explotar GPL, donde trataba con detalle su vinculación profesional y personal con el software libre, y al mismo tiempo, explicaba la forma en la que muchas personas se aprovechan de ella, buscando exclusivamente un beneficio personal.
+Con José Conti discutimos entre varias cuestiones, la finalidad de la licencia GPL, cómo encaja la GPL en el desarrollo y venta del software, su financiación y el día a día de un desarrollador que vive de un proyecto bajo esa licencia.
+Entre las preguntas planteadas a José Conti, tenemos:
+-
+
- ¿Qué fines fundamentales persigue la licencia GPL? +
- ¿Es acertado el planteamiento de la licencia GPL a la hora de repercutir valor económico al desarrollador?. +
- En tu artículo explicas que se han popularizado los sitios de reventa de plugin con un precio inferior y saltándose al desarrollador. Se amparan en que la GPL permite vender software, aunque sea una de las cuestiones más complicadas de entender de la licencia…¿Cómo explotan estos sitios la filosofía abierta de la GPL? +
- ¿Son los usuarios conscientes de lo que cuesta mantener los proyectos de software? +
- ¿Qué modelo considerarías más acertado para recompensar a los desarrolladores de software libre? +
- ¿Qué visión tiene la comunidad WordPress respecto a la GPL? +
- ¿Cómo es tu plugin de RedSys por dentro y qué relación tienes con ellos? +
En resumen una animada conversación con un profesional del software vinculado a un proyecto GPL y con una experiencia de gran valor creando soluciones abiertas y libres.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Roy Fielding’s Misappropriated REST Dissertation
+Two-Bit History 28 06 2020
+
+
+ A Brief Hiatus
+Josh Comeau's blog 25 06 2020
+
+
+ I’m a Gen Z-er and I want you to stop using emojis
+blog.karenying.com 24 06 2020
+
+
+ Clojurists Together Summer of Bugs Selections
+News on Clojurists Together 23 06 2020
+
+ 
+
+
+ Schmuck
+MonkeyUser 23 06 2020
+
+
+ Configuring a Mac for a PC User
+blog.karenying.com 22 06 2020
+
+
+
+
+ David Vaquero hace balance de su primer año en el podcast
+República Web 20 06 2020
+El primer aniversario de nuestro compañero David Vaquero en el podcast, nos da pie a realizar un episodio personal donde David nos cuente lo que ha supuesto este primer año. Aunque en este episodio hablemos de la experiencia de David, es un buen episodio para destacar lo que supone participar y producir un podcast. Es una buena oportunidad también para hacer algo de balance del último año y hablar sobre la dirección que puede tomar el programa en el futuro.
+Entre las cuestiones que hablamos con David se incluyen:
+-
+
- ¿Cómo empezaste a escuchar el podcast? +
- ¿Qué ha mejorado de tu parte profesional y personal hacer este podcast? +
- Te estás encargando de poner videos en tu canal de Youtube …¿Qué tal la experiencia? +
- ¿En qué dirección debería progresar el programa? +
En la segunda parte del programa tratamos en la sección Radar, la aparición de la nueva versión de Bootstrap en su quinta edición (en alpha), también de Quasar un framework basado en VUEJS para PWA, Cordova/Capacitor y Electron. Por último comentamos un interesante recurso pedagógico para comprender mejor Amazon Web Services.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Adding Transitions to a React Carousel with Material-UI
+blog.karenying.com 16 06 2020
+
+
+ LOS RESIDUOS EN CANARIAS. LA CULTURA DEL USAR Y TIRAR. VERTEDEROS ILEGALES.
+Andanzas de una ambientóloga . . . 16 06 2020
+
+ 
+
+
+ Release Cycle
+MonkeyUser 16 06 2020
+
+
+ May 2020 Monthly Update
+News on Clojurists Together 15 06 2020
+
+
+ April 2020 Monthly Update
+News on Clojurists Together 15 06 2020
+
+
+ Let 2020 be the year PNG icons die
+blog.karenying.com 14 06 2020
+
+
+
+
+ Lenguajes de backend más utilizados y presentación de Tadam framework web en Clojure
+República Web 12 06 2020
+Seguimos en el podcast con los estudios de las tecnologías más utilizadas en la web, basado en el estudio de David Vaquero sobre el millón de páginas web según Alexa. En esta ocasión nos detenemos a analizar los datos de los lenguajes de backend más utilizados. Uno a uno vemos los principales lenguajes y tecnologías web que representan el top del ranking. Entre ellas:
+-
+
- PHP +
- LUA+ OpenResty +
- Python +
- Asp.NET +
- Java + OpenGSE +
- Ruby + Ruby on Rails +
- Javascript + NodeJS + ExpressJS +
Accede al estudio de David Vaquero en su página web. Estudio lenguajes Backend sobre millón de sitios web de Alexa.
+En la segunda parte Andros nos trae su último proyecto, un framework web llamado Tadam y que está realizado en Clojure. Se trata de un minimalista framework para crear sitios web dinámicos orientados a la programación funcional. Andros nos cuenta el potencial de Clojure para un desarrollo moderno y más fiable, al depender de un paradigma funcional, más fácil de detectar errores y mucho más predecible.
+Para finalizar el episodio traemos en la sección de Radar, unos cuantos recursos de interés, noticias y herramientas que os ayudarán en vuestro desarrollo profesional. También comentamos algunas de las encuestas que Andros ha lanzado en nuestro grupo de Telegram Malditos Webmasters.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Using Netlify Functions with Gatsby
+Josh Comeau's blog 10 06 2020
+
+ 
+
+
+ Pair Programming
+MonkeyUser 09 06 2020
+
+
+ Reflexiones. COVID-19, medio ambiente y sociedad.
+Andanzas de una ambientóloga . . . 08 06 2020
+
+
+
+
+ Importa las tablas de tu base de datos a un nuevo proyecto Laravel
+Javier Archeni 07 06 2020
+
+
+ Looking for a Lisp Web Developer (not a real job, but nearly)
+Lisp journey 05 06 2020
+Dear lispers,
+ +I decided that I can not develop three projects in parallel fast enough, so I’m seeking for a fellow programmer to join the effort.
+ +Disclaimer: this is not a real position, but there is a little budget
+ +I recently presented my online catalogue for bookshops. You will work on something very similar, but bigger. I need help to re-write the existing free software for bookshops in Common Lisp. The existing one is in Python. I have a prototype of the new CL one.
+ +The software specifications are here and are good. We wrote them years +ago by consulting people selling books, and we now grow on our +experience acquired developing the first Python app as well as on the +feedback gathered from clients. The challenge is to build a +maintainable, fast, bug-free, easily-deployable application with an +user interface that answers the clients’ needs.
+ +I ask you to have some experience in:
+ +-
+
- Common Lisp +
- the web: HTML, CSS, web browser API +
- SQL +
You should also have a sufficiently good english to speak with me (a non-native speaker).
+ +I would have tasks for you in June and July, nothing in August, and +hopefully more in September and onwards.
+ +Bonus points include, in no particular order:
+ +-
+
- acquaintance with JavaScript, with a JS framework (preferably Vuejs) +
- good HTML&CSS design skills +
- you speak french +
- you have a good english, or good communication skills in your mother tongue +
- good backend and “devops” experience +
- Python experience to install and study an existing project +
If this appeals to you, please email me at (reverse
+"gro.zliam@leradniv") and indicate roughly how you stand in these
+points, your availability in June, during the upcoming two weeks
+for a meeting, and we’ll speak further.
Thanks!
+ +
+
+ Stop Using datetime.now!
+Haki Benita 31 05 2020
+If you ever had a test that one day just started to fail, unprovoked, or a test that fails once every blue moon for no apparent reason, it's possible your code is relying on something that is not deterministic. In this article I describe a practical approach to dependency injection in Python that when used correctly, can eliminate nondeterminism and make your code easier to maintain and to test.
+
+
+
+
+ En qué ando: edición confinamiento
+Onda Hostil 31 05 2020
+
+
+
+
+ Las crónicas de los navegadores web con Álex Barredo
+República Web 30 05 2020
+Invitamos a Álex Barredo para hablar sobre el estado de los navegadores web y el ecosistema actual de uso. Además de su faceta de divulgación tecnológica en sus diferentes canales (mixx.io podcasts y newsletters), Álex también siente debilidad por el mundo de los navegadores y hasta tuvo un blog donde contaba las novedades que iban surgiendo en torno a ellos. En este episodio especial hablamos con Álex de la situación actual y del aplastante liderazgo de Google en el ámbito de los navegadores de escritorio y móviles.
+Entre las cuestiones que tratamos:
+-
+
- ¿Seguirá siendo todavía más en el futuro? ¿Se vislumbran planes para limitar con legislación antimonopolio al gigante de Google? + +
- El año pasado Microsoft Edge se rindió a los pies de Chromium, el software de código abierto que lidera Google, pasando a usar Blink y V8 como motores.¿Ha sido una decisión buena para Microsoft y mala para competencia?. + +
- Primeros navegadores, orígenes de Internet Explorer y las guerras de los navegadores en el 2000. +
- Porcentajes de uso, competencia actual entre navegadores y situación con respecto Europa, América y Asia. +
- El papel de la fundación Mozilla y el estado actual de Firefox. +
- Modelos de negocio alternativos para los navegadores y caso Brave. +
- Apple y su papel en el desarrollo con Safari. +
Posiblemente Álex sea una de las personas mejor informadas del panorama tecnológico y es un lujo poder compartir con él un rato para hablar sobre el estado actual de los navegadores web. Sin duda es un tema que seguirá avanzando durante los próximos meses y que ofrece un escenario donde los grandes de internet y la tecnología se disponen a seguir combatiendo en uso y funcionalidades.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ A free software for bookshops to show their catalogue online
+Lisp journey 30 05 2020
+I wrote a free software for bookshops to publish their catalogue +online. Clients can now browse the available books and order them. It +is enough generic so we can show other products too.
+ +-
+
- https://abstock.gitlab.io/#/en/ +
- sources and bug tracker: https://gitlab.com/vindarel/abstock +
- Github mirror: https://github.com/vindarel/ABStock +
- the demo +
Here’s how a search result looks like:
+ +
Features
+ +The website is made generic enough for different clients, and is made +totally hackable with pre- and post- configuration files that load +your Lisp logic.
+ +By default we get the following pages:
+ +-
+
- the welcome screen, with:
+
+
-
+
- the bookshop’s information, +
- the search form. We can search by title, authors, publisher, shelf and ISBN(s). +
- a random pre-selection of the books to showcase, if enabled. +
+ - an optional special page to showcase a selection of books or other products. +
- in the search results page, visitors can add a book to their shopping basket. +
- and in the basket page, they find a confirmation form, which sends +the command by email to the shop owner. +
There are obvious TODOs, that could be shocking by their absence, but +that I actually don’t need yet, so they’ll come right in time :)
+ +-
+
- online payment +
- admin page
+
+
-
+
- simple stats (they are brought in with the email provider, and with Matomo statistics) +
+ - i18n, remove a still few hardcoded words +
Data
+ +ABStock connects by default to the Abelujo +database. Abelujo is a free software for bookshops that I also +develop. Booksellers use it for their daily work, registering and +selling books.
+ +But we can define our own products. The current possibility is
+to use a cards.txt file. Each block expects a title, and that’s
+the only mandatory field. Other recognized fields are:
((:|id| integer)
+ :|title|
+ :|cover|
+ :|isbn|
+ :|price|
+ :|author|
+ :|publisher|
+ :|date_publication|
+ :|date-publication|
+ :|shelf|
+ :|shelf_id|
+ :|details-url|
+ :|summary|
+ :|quantity|
+ :|repr|
+ :|repr2|)
+We can define other fields, like likes below, which is
+actually unused in the application.
[…]
+
+title: Programming Algorithms
+author: Vsevolod Domkin
+cover: https://d2sofvawe08yqg.cloudfront.net/progalgs/hero?1586867024
+details-url: https://leanpub.com/progalgs
+shelf: programming
+shelf_id: 99
+publisher: Leanpub
+price: 15
+likes: 5
+
+title: Cats
+author: mother cat
+cover: https://gitlab.com/abstock/abstock.gitlab.io/-/raw/master/logo.png
+details-url: https://gitlab.com/abstock/abstock.gitlab.io/-/blob/master/logo.png
+shelf: nature
+shelf_id: 98
+publisher: nature
+price: 5
+likes: 100
+
+title: Screwdriver
+author:
+cover: https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Ftse1.mm.bing.net%2Fth%3Fid%3DOIP.jGOb7dVL1oA9VDzNVPDPpwAAAA%26pid%3DApi&f=1
+details-url:
+shelf: craftmanship
+shelf_id: 97
+publisher:
+price: 10
+likes: 1
+(yes there’s a little redundancy with shelf and shelf_id to fix)
+ +That gives:
+ +
We could very well load a JSON, a CSV or another database when the need arises.
+ +For now, we think the text loader is enough for you to define your +products and try the application.
+ +It is also very easy to host, and in doing so one can realize that to live-reload his Lisp web app is straighforward and very convenient.
+ +Context
+ +I shipped the app the second month of our lockdown period for the +client I was working for at that moment, and no need to say it turned +100% helpful. Amazon had hell of an activity, and french alternatives +for booksellers (such as lalibrairie.com or placedeslibraires.fr) +either had stopped, either couldn’t accept new registrations. So we +were left alone, and we did that. His clients were happy, they started +passing orders, he organized collection schedules. This happened in a +small rural village, where the inhabitants are happy to have, at +least, a (nice) bookshop in their village.
+ +Paying one’s rent with Lisp
+ +So yes, I paid my rent with Common Lisp again \o/ And you see, the +software is a classical web app. I could have made it with Python or +another language that has a web server and a templating library. As I +defended before, the app doesn’t exist thanks to CL’s super powers. CL +had no particular advantages for this kind of web app, but no +disavantages either: it has a good web framework, a good templating +library that I liked a lot (Djula: defining custom filters was a +breeze), a good SQL wrapper, and that’s all I asked. I use CL’s +super powers during development and deployment. Clients wouldn’t see +the difference… or would they?
+ +Actually, CL has advantages overall: development speed, ease of +deployment, ease of hot-reload, ease to use the language features to +bypass a library’s limitation (easy-routes had no built-in to +translate a route URL, but it turned possible with a reader macro)… +not mentioning ease of maintenance in time, speed, etc.
+ +One production bug I had was due to (me apart for not testing enough)
+(= 3 nil) throwing an error, so you must had prior checks (or, I
+just realize, use equalp?). My Sentry dashboard is empty anyways.
Final words (with bonus)
+ +The Big Plan is to Rewrite It (the other software) In Lisp, and the +project just moved from R&D to POW… stay tuned, particularly if you +don’t know what to do in june and july, I might have a small budget +for a helping hand.
+ ++ +
| +Become a Patron! + | + +
+
+
+ |
+
+
+ Scraping a website
+Posts on James Routley 27 05 2020
+
+
+ Local Testing on an iPhone
+Josh Comeau's blog 26 05 2020
+
+ 
+
+
+ Dev's Journey
+MonkeyUser 26 05 2020
+
+
+ Bespoke software, and a really simple RSS aggregator
+Posts on James Routley 25 05 2020
+
+
+
+ How you can help keep blogging alive and thriving
+Marko Saric 24 05 2020
+
+
+
+
+ Administración y gestión de VPS con Manuel Rosa
+República Web 23 05 2020
+Hablamos sobre administración y gestión básica de VPS con Manuel Rosa, un inquieto Ingeniero de Telecomunicaciones especializado en electrónica. Manuel lleva varios años dedicándose a diferentes facetas del mundo tecnológico y todavía sigue iniciando diversos proyectos. Actualmente Manuel Rosa trabaja para una empresa de seguridad informática y además saca tiempo para realizar sus propios proyectos de e-commerce, marketing y SEO.
+Con Manuel Rosa hablamos sobre la administración esencial de VPS, la tremenda competencia que existe en el mercado de servidores virtuales y sobre las herramientas recomendadas para gestionar tu propio VPS. Con Manuel hablamos de las siguientes cuestiones:
+-
+
- ¿Qué criterios deberíamos tener en cuenta para escoger un buen proveedor de VPS? ¿Algunas recomendaciones personales?. +
- ¿Qué es lo primero que configuras en una VPS a parte de la clave ssh? +
- ¿Qué acciones recomiendas realizar para garantizar la seguridad mínima en un VPS? ¿Cuáles son las amenazas más habituales?. +
- ¿Qué distribución recomiendas para la VPS?. +
- ¿Qué tareas de mantenimiento son necesarias para un correcto funcionamiento de un VPS?
+¿Cómo gestionas el backup de una VPS? ¿Algún software recomendado?.
+ - Docker y kubernetes para manejar la infraestructura. +
- ¿Cómo ves el futuro de este tipo de productos?. +
- ¿Cuándo deberíamos pasar a un servidor dedicado?. +
Una interesante charla con Manuel al que emplazamos a otro episodio para que nos cuente otros proyectos y su experiencia a la hora de lanzar proyectos comerciales en internet. Puedes contactar con Manuel a través de su propio LinkedIn.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ It's 2020: let's build a node.js app with TypeScript
+Blogs on Tom Spencer 22 05 2020
+
+
+ It's 2020: let's build a node.js app with TypeScript
+Blogs on Tom Spencer 22 05 2020
+
+
+ Animated Sparkles in React
+Josh Comeau's blog 19 05 2020
+
+ 
+
+
+ Code Superheroes
+MonkeyUser 19 05 2020
+
+
+ Announcing the Clojurists Together Foundation
+News on Clojurists Together 18 05 2020
+
+
+ Announcing Summer of Bugs
+News on Clojurists Together 18 05 2020
+
+
+ Creating helper commands for k8s using fzf
+(ノ°Д°）ノ︵ ┻━┻ 17 05 2020
+
+ 
+
+
+ Creating helper commands for k8s using fzf
+(ノ°Д°）ノ︵ ┻━┻ 17 05 2020
+
+Kubernetes cli tool kubectl is pretty useful but when I need to execute some tasks many times during a work day it could be too verbose. So I wrote some bash functions to handle a few common tasks I use often.
+I used the power of fzf to create an interactive experience when I run any of these functions. Basically it pipes the output of a kubectl command, make some filtering using sed and awk and then build a final command which will execute what I want.
+The common behavior of these functions is first ask for a namespace and then ask for a specific pod to make some action over its.
+We can see an example of how it works in the image below:
+
+
+
++Open a shell or a custom command inside a pod +
+
+
+
+If we execute pod_shell without any argument it will connect to the selected pod and run bash, otherwise it will run the given command.
+
+
+function pod_shell {
+ local namespace=`kubectl get ns | sed 1d | awk '{print $1}' | fzf`
+ local pod=`kubectl get pods -n $namespace | sed 1d | awk '{print $1}' | fzf`
+ echo "Connecting to $pod"
+
+ if [ -z $1 ]
+ then
+ kubectl -n $namespace exec -ti $pod bash
+ else
+ kubectl -n $namespace exec -ti $pod $1
+ fi
+}
+
++Run a proxy over a pod +
+
+
+
+Same as the previous function but this one ask for a port mapping, for example 9999:5432 will map the port 9999 from the host machine to 5432 port on the pod.
+
+
+function pod_proxy {
+ local namespace=`kubectl get ns | sed 1d | awk '{print $1}' | fzf`
+ local pod=`kubectl get pods -n $namespace | sed 1d | awk '{print $1}' | fzf`
+ local port_mapping
+ echo "Enter port mapping using the form local_port:pod_port"
+ read port_mapping
+ echo "Setting up proxy to $pod on $port_mapping..."
+
+ kubectl port-forward -n $namespace $pod $port_mapping
+}
+
++See realtime logs for a given pod +
+
+
+
+This one just ask for a pod and attach a kubectl log command.
+
+
+function pod_logs {
+ local namespace=`kubectl get ns | sed 1d | awk '{print $1}' | fzf`
+ local pod=`kubectl get pods -n $namespace | sed 1d | awk '{print $1}' | fzf`
+ echo "Showing logs for $pod"
+
+ kubectl -n $namespace logs -f $pod
+}
+
+
+ +Change context +
+
+
++Switch between configured contexts
+
+
+
+function k8s_change_context {
+ local context=`kubectl config get-contexts --output='name' | fzf`
+ echo "Changing to $context"
+ kubectl config use-context $context
+}+These are some common tasks I need for a day of work but with the same logic we can build some other commands.
+
+
+ Avoid losing window layout when editing org code blocks
+(ノ°Д°）ノ︵ ┻━┻ 16 05 2020
+
+ 
+
+
+ Avoid losing window layout when editing org code blocks
+(ノ°Д°）ノ︵ ┻━┻ 16 05 2020
++Org-mode has a nice feature that allow us to edit source code within an org file, for more info check the docs. But it has a little annoying behavior after we are done editing a source block. It loses the previous window configuration and always closes all the windows except the org window.
++In the image below we can see this behavior:
+
+To solve this problem we can use a simple variable to store the current window configuration just before the source code edition buffer is opened and when it's closed we can restore the previous configuration just getting the value from the variable used before. We're defining two functions to accomplish this behavior, one to run before and one after we're done editing the source block.
+
+
+
+(defvar my/org-src-block-tmp-window-configuration nil)
+
+(defun my/org-edit-special (&optional arg)
+ "Save current window configuration before a org-edit buffer is open."
+ (setq my/org-src-block-tmp-window-configuration (current-window-configuration)))
+
+(defun my/org-edit-src-exit ()
+ "Restore the window configuration that was saved before org-edit-special was called."
+ (set-window-configuration my/org-src-block-tmp-window-configuration))+Now we need to "attach" these two functions to the default behavior of org-mode, to do this we can use advice-add elisp function, this function allow us to "attach" some functionality to an existing function.
++The two functions that we need to advice are:
+-
+
-
+
+org-edit-special: this function is called when we pressC-c C-'and allow us to edit source block in a dedicated buffer.
+ -
+
+org-edit-src-exit: this function is called when we pressC-c C-'from inside of the opened buffer, it closes the buffer and return us to the org buffer.
+
+ my/org-edit-special will run just before org-edit-special is called and my/org-edit-src-exit after org-edit-src-exit is called.
+We need to execute this code after org is loaded so we use eval-after-load.
+
+
+(eval-after-load "org"
+ `(progn
+ (advice-add 'org-edit-special :before 'my/org-edit-special)
+ (advice-add 'org-edit-src-exit :after 'my/org-edit-src-exit)))+The full code will be:
+
+
+
+(defvar my/org-src-block-tmp-window-configuration nil)
+
+(defun my/org-edit-special (&optional arg)
+ "Save current window configuration before a org-edit buffer is open."
+ (setq my/org-src-block-tmp-window-configuration (current-window-configuration)))
+
+(defun my/org-edit-src-exit ()
+ "Restore the window configuration that was saved before org-edit-special was called."
+ (set-window-configuration my/org-src-block-tmp-window-configuration))
+
+(eval-after-load "org"
+ `(progn
+ (advice-add 'org-edit-special :before 'my/org-edit-special)
+ (advice-add 'org-edit-src-exit :after 'my/org-edit-src-exit)))+After applying the complete code the result will be:
+
+Enjoy!
+ +
+
+
+
+ Son sitios estáticos y sin embargo, se mueven
+República Web 16 05 2020
+Dedicamos este episodio a hablar sobre los sitios estáticos y el espectacular crecimiento que está experimentado el ecosistema. Sin duda el auge del JAMstack, está revolucionando la forma de trabajar un sitio web, con flujos de trabajo más sencillos, costes de mantenimiento más bajos y un rendimiento muy superior en tiempos de carga, a los acostumbrados con sistemas dinámicos. Gracias a la gran cantidad y calidad de generadores de sitios estáticos, podemos ofrecer soluciones web que ofrecen un entorno moderno de desarrollo y al mismo tiempo, aprovechan las tecnologías de acceso a datos a través de API. Desde sencillas páginas corporativas hasta blogs y páginas personales, las páginas estáticas resultan una solución ideal para servir proyectos más escalables, sin casi necesidad de mantenimiento.
+Las herramientas derivadas del JAMstack están propiciando que servicios como Netlify o Vercel, permitan el despliegue global de complejos proyectos web, a través de su plataforma y con unos costes que se encuentran muy por debajo de soluciones similares. También existen soluciones que permiten desacoplar tu CMS y concentrarte por separado en las capas de presentación y datos (Headless CMS). El futuro de estas herramientas pasa por integrar cada vez más a los usuarios finales (CMS más fluidos y fáciles de editar) y en proporcionar integraciones con otros servicios a través de APIs o servicios externos.
+Entre las cuestiones tratadas en el episodio:
+-
+
- ¿Qué es un sitio estático y qué ventajas ofrecen? +
- ¿Deberían ser muchos sitios web estáticos? ¿CMS innecesario? +
- Explosión de generadores de sitios estáticos. +
- El auge del JAMStack. +
- ¿Qué son los flat-file CMS?. +
En la segunda parte del episodio ofrecemos interesantes recursos y enlaces relacionados con el desarrollo web. Encuentras todos esos enlaces más abajo y también los discutidos en el episodio.
+Versión vídeo con capturas de la sección Radar
+ +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ Today I Realized that to live reload my Lisp web app is straightforward and so convenient
+Lisp journey 12 05 2020
+We all know that we can start a web server in the REPL and develop a
+web app as interactively as any other app, we know how to connect to
+a remote Lisp
+image
+by starting a Swank server and how to interact with it from our
+favorite editor on our machine, we know we can build a self-contained
+binary of the web app and simply run it, but one thing I had not
+realized, despite being the basics, is that by starting the web app
+with sbcl --load app.lisp, we are dropped into the regular Lisp
+REPL, with the web server running in its own thread (as in development
+mode, but unlike with the binary), and that we can consequently interact with the running app.
As a demonstration, you can clone this repository and run the example like this:
+ +* rlwrap sbcl --load run.lisp
+
+This is SBCL 1.4.5.debian, an implementation of ANSI Common Lisp.
+re information about SBCL is available at <http://www.sbcl.org/>.
+[…]
+; Loading "web-live-reload"
+..................................................
+Starting the web server on port 7890
+Ready. You can access the application!
+*
+it will load project.asd, install 3 Quicklisp dependencies (you must
+have Quicklisp installed), start Hunchentoot on port 7890, and drop us
+into a REPL.
You’ll get this:
+ +
The template prints the *config* variable, which you can change in the REPL:
* (in-package :web-live-reload)
+* (setf *config*
+ '((:key "Name"
+ :val "James")
+ (:key "phone"
+ :val "0098 007")
+ (:key "secret language?"
+ :val "Lisp")))
+refresh, and voilà, your new config is live.
+ +For functions, it is just the same (redefine the function fn that
+returns a string, if you want to try).
If a file changes (for example after a git pull), compile it with a
+usual load: (load "src/web.lisp").
You can also reload all the app with (ql:quickload :myproject),
+which will install the dependencies, without needing to restart the
+running image.
I was looking for a way to reload a user’s config and personal data +from a running website, and this has proved very practical. I have no +downtime, it is pure Lisp, it is the workflow I am used to. I am more +cautious on using this to recompile the whole app, even though I did +it without glitches so far. The thing to not do is to change the +global state manually, aka to develop in production!
+ +That’s all, but that made my day.
+ ++ +
Bonus points:
+ +-
+
- after a git pull, the (Djula) templates are automatically
+updated. No operation is needed to see them live. (you can disable
+this by pushing
:djula-prodinto the features set)
+ - you’ll understand and appreciate the difference between
+
defparameteranddefvar. Imagine you declare a variable with +(defparameter *data* nil)and you populate it with some heavy +computation at the application startup. Now if youloadthe file +this declaration is in, you’ll set the data back tonil. If you +declare it withdefvar, you can live-reloadyour app and the +data doesn’t go away. You can try both cases with the*config*+variable.
+ - the app started a Swank server on port 4006, if you want to try on your VPS. +
+ + + +
+
+ I Worked Remotely in Common Lisp. Here's My Incredible Story.
+Lisp journey 12 05 2020
+Nearly one year ago, I received an email that asked me if I was +available to do remote Lisp work. It was the day before the end of a +contract and I had to tell my team if I wanted to continue or not. I +made a virtual offering to the Lisp god and I started the Lisp job.
+ ++ +
Disclaimer: this post was written on Lisp Advocates’ +reddit. Lisp Advocates is a meme, but it’s sort of serious too.
+ ++ +
At this time I had been in Lisp for around two years, contributing a +couple simple libraries, writing a lot of documentation, blogging, +furnishing the reddits, and being enthusiastic and polite. This is +what actually gave me the job. I had tried to contribute to a busy CL +repository, but the PR was not good enough and that irritated the +maintainer, who answered abruptly. Nothing’s more outrageous than +receiving contributions right? But I answered with calm and +professionalism, and that got noticed by a repository watcher, who +decided he could work with me.
+ +That guy already had contacts and a client, and he formed a team +around him. Our work was to build a website that would receive many visitors, +that would have a client registration form and would +have a rather simple admin dashboard, for a team of half a dozen +people. The business already existed in the form of a buggy and slow +Wordpress site, so the expectations were clear. We were three, we +worked together on the same code (with one guy more on the design). I +worked on it in a two-months period, but not full time. I’ve had a +decent income paid straight and so I paid my rents for a few months +thanks to that experience.
+ +What Lisp was good for
+ +The application had no inherent difficulties. It had forms and an +admin backend. It was a website for a team of commercial people, as it +exists hundreds of thousands. And yeah, Common Lisp was suited for +that task. So we see there’s a good margin of progression, business +and remote work wise: those thousands of websites for commercial +people can very well be done in CL.
+ +Libraries, deployment and Lisp curse
+ +We picked the Caveman framework, the Mito ORM and the cl-markup +templating library, with some tests in FiveAM. There was a little bit +of JavaScript, less than a thousand lines. I find Caveman a bit +convoluted but it was clear and easy. I like Mito very much and wrote +material for it. I liked to play with the web server debugging options: usually I +received the stacktraces in the debugger in my editor, but I could +choose to display them on the browser (as I’m used with Django or +Flask). It is this time that I enjoyed so much being able to change +the faulty function, recompile it, choose the “try again” restart and +see the operation succeed. Now when I’m back on Python I feel the Lisp +curse. I’ll never be the same. I’ll never enjoy Python as much as +before. Sigh. Anyways, we deployed the app on DigitalOcean with Fast +CGI, as documented on Caveman’s README.
+ +The bug
+ +Our most difficult bug that made us loose millions was due to
+(string-downcase nil) to return “NIL”, the string, instead of
+nil. Now I use my str library
+for string manipulation purposes.
All in all, being able to live-debug the software from the earth +proved invaluable.
+ +I got also hit by a config of mine that impacted Mito’s results. I had
+set *print-case* to :downcase in my .sbclrc. I was asking Lisp to
+DON’T SHOUT AT ME ALL DAY LONG, ‘cause I try to listen to music at the
+same time. I fixed the Mito bug, but I don’t use this setting anymore.
Voilà. This is my response to LispAdvocates’ call: https://www.reddit.com/r/lispadvocates/comments/ficdvx/tell_us_you_remote_success_story/.
+ +There are of course lots of situations were CL is ready now to get the (remote) job done. There are people who do web dev for years in CL, but we don’t know their story.
+ +Share yours!
+ +ps: stay tuned, ‘cause I deployed another website in production.
+ ++ +
Some comments and answers:
+ +++ +Apart from the programmer experience, were there any inherent advantages to using Common Lisp? (Speed I guess?)
+
CL had no particular advantages, but no disadvantages either (and it +is my point!). As I said, it was a site with basic/easy/HTML&JS +requirements, so I believe no language would’ve had any particular +advantage. Speed was important, it was one of the main +requirements. The website felt responsive, the client was very happy +about it. For us, it was also easy and fast to deploy, which turned +important and impressed the client.
+ +++ +Do you thinK a more standardized framework (from other languages) could have saved you?
+
No, not with our requirements. Another framework&language would have +make us loose millions at the very beginning (still figuratively)
+ +
+ 
+
+
+ Informe sobre herramientas DevOps 2020
+República Web 09 05 2020
+Dedicamos este episodio al DevOps Tools Report 2020 realizado por Gitkraken. Este informe proporciona una guía sobre las mejores herramientas DevOps, según una comunidad global de 2700 desarrolladores. DevOps se está convirtiendo en el estándar para realizar operaciones y desarrollo de software. Este completo informe hace un recorrido de las herramientas DevOps usadas en la actualidad para dibujar, un ciclo de vida completo del desarrollo de software.
+
Como indican en la introducción del informe, la transición hacia una cultura de DevOps requiere cambios significativos que incluyen un cambio en la mentalidad del personal, la introducción de las herramientas apropiadas y la adquisición de nuevas habilidades. Sin importar en qué fase te encuentres de tu transformación DevOps, el foco debería estar siempre en la mejora continua. Comienza con las bases y después identifica tus limitaciones propias. Una vez superes esas limitaciones, repite el proceso.
+El informe se muestra siguiendo un gráfico en forma de infinito, donde se muestra la condición de continuidad y de iteración en el proceso de DevOps. Las fases corresponden a cada una de las disciplinas del desarrollo moderno de software: Planificación, codificación, Empaquetado / construcción, Testeo, Configuración y lanzamiento, Despliegue, Operaciones y Monitorización.
+Cada uno de estas fases incluyen unas herramientas, que a menudo, se van repitiendo en otras fases:
+| +FASE + | ++Herramientas + | ++Otras + | +
|---|---|---|
| PLAN | +Jira, Trello, Gitkraken Boards, GitKraken Timelines. | +BaseCamp, MantisBT. | +
| CODE | +Hosting: GitHub, Bitbucket, GitLab y Azure DevOps. +Git / SCM: GitKraken Git GUI, CLI, GitHub Desktop, Sourcetree. +IDE: VS Code, IntelliJ, Visual Studio, Sublime Text. |
+Eclipse | +
| BUILD | +Jenkins, Maven Visual Studio, Gradle | ++ |
| TEST | +JUnit, Selenium, Jest, PHPUnit. | +Cypress, Postman, Swagger. | +
| RELEASE | +Ansible, Azure DevOps, Chef, Jenkins, AWS Codebuild. | +Puppet, Circle CI. | +
| DEPLOY | +Jenkins,Azure DevOps, AWS Codebuild, GitLab. | ++ |
| OPERATE | +Kubernetes, Docker, AWS | +|
| MONITOR | +Google Analytics, Grafana, Azure Monitor, AWS CloudWatch | +Datadog, New Relic | +
En el episodio destacamos el auge imparable en los últimos años de las herramientas cloud y cómo la metodología DevOps irá creando perfiles específicos que gestionen su complejidad.
+También dejamos el webinar que realizó la semana pasada David Vaquero para Nextraining y titulado, 4 Herramientas OpenSource Imprescindibles en el Testing Web. En este webinar David explica JUnit, Selenium, JMeter y Jenkins.
+ +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+ How to fix the broken web as a site owner and web developer
+Marko Saric 07 05 2020
+
+
+ Lessons Learned Speaking at Conferences
+Josh Comeau's blog 06 05 2020
+
+
+ How to Move a Django Model to Another App
+Haki Benita 05 05 2020
+In my latest article for RealPython I cover some exotic migration operations, many of the built-in migration CLI commands and demonstrate important migrations concepts such as reversible migrations, migration plans and introspection.
+
+
+ Accessible Animations in React
+Josh Comeau's blog 05 05 2020
+
+ 
+
+
+ Diff
+MonkeyUser 05 05 2020
+
+
+
+
+ Reconversión de negocios y profesionales al mundo de internet
+República Web 02 05 2020
+Con las crisis llegan momentos de cambios de rumbo y nuevos horizontes. Los recientes acontecimientos han puesto al sector online en el centro de muchas acciones, encaminadas a la búsqueda de empleo o ampliar actividades relacionadas con internet. En este episodio hablamos sobre cómo afrontar la reconversión de profesionales y negocios al mundo de internet. Tanto en en el sector formativo de nuevas tecnologías como en otras actividades, es innegable que se está experimentado un renovado interés. Por tanto, uno de las grandes discusiones que realizamos en el episodio es ¿Qué le diríamos a las personas que desean ampliar su horizonte en el área digital?
+Reservamos la segunda parte del episodio a aportar interesantes enlaces de recursos y herramientas orientadas al desarrollo y programación. Más abajo encontrarás todos los enlaces discutidos en el episodio.
+ +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Testing an Interactive Voice Response System With Python and Pytest
+Haki Benita 30 04 2020
+It can be very challenging to test a system that rely heavily on a third party service such as Twilio. In this article, I show how to organize your code in a way that would isolate your bushiness logic and make it easier for you to test it separately.
+
+
+
+ Please get your parents off Facebook
+Marko Saric 30 04 2020
+
+
+ Incredimental Builds!
+Josh Comeau's blog 29 04 2020
+
+
+ Deploying Netlify Functions with Gatsby Cloud
+Josh Comeau's blog 28 04 2020
+
+ 
+
+
+ Estimates
+MonkeyUser 28 04 2020
+
+
+
+
+ Repositorios, control de versiones y despliegues en GitHub y GitLab
+República Web 25 04 2020
+Dedicamos este episodio a hablar sobre los repositorios Git en la nube, espacios que nos permiten mantener una versión de nuestro código, trabajar de manera colaborativa, ejecutar tests y también realizar despliegues y otras mágicas funcionalidades. Empezamos el episodio tratando sobre en qué consiste un repositorio de código y cómo Git se ha convertido en el estándar a la hora de pensar en control de versiones. Centramos la conversación sobre los dos proveedores más importantes: GitHub y GitLab. El primero está considerado como la red social del código y tras su adquisición por parte de Microsoft está incorporando multitud de funcionalidades en su capa gratuita. Por su parte, GitLab es una soberbia plataforma de código abierto, dirigida a ser la solución integral para DevOps y una aplicación de Integración y Desarrollo Continuo para proyectos de software.
+Entre las cuestiones que tratamos en el episodio, tenemos:
+-
+
- Sistema de control de versiones Git y su uso local. +
- Diferencias esenciales entre GitHub y GitLab. +
- Clientes GUI: Github Desktop, Gitkraken, SourceTree, Git GUI, Tower, Lazygit, Sublime merge + +
- Integración con IDE’s: Atom, Brackets, Jetbrains (integración con GitHub, Git), VSCode, + +
En el episodio también comentamos las cifras de una encuesta que realizamos en el grupo de Telegram Malditos Webmasters sobre el uso de estas herramientas. Las cifras son Github 64%
+Gitlab 20% y Bitbucket 13%.
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Instapaper Save for macOS v1.1
+Instapaper 24 04 2020
+Today we updated the Instapaper Save macOS app to include more features including inline saving on Twitter, keyboard shortcut to save (Ctrl + S), and support for pasting credentials from password managers.
We also built a Share Extension for Instapaper Save, which lets you save to Instapaper from apps like Mail, News, and any other apps that support the macOS share sheet. The Share Extension also allows you to right-click links in Safari to save them.
Once you’ve downloaded the update, you can enable the system-level share by opening the share sheet from any macOS app > Going to “More…” > Selecting Instapaper in the Share Menu section of the Extensions menu. If you were doing that from Safari, it would look like this:
+ +Lastly, we also updated our Chrome extension and Firefox add-on to fix inline saving from Twitter, and updated the Firefox shortcut to use Ctrl + S so it no longer interferes with the screenshot tool.
If you have any questions, feature requests, or issues you’d like us to sort out, please let us know at support@instapaper.com or @InstapaperHelp on Twitter.
Thanks for using Instapaper!
+
+
+
+ How to de-Google your site to make it faster and visitor friendly
+Marko Saric 24 04 2020
+
+ 
+
+
+ Tutorial de useState() en React.js
+Blog de Diseño Web Vida MRR 23 04 2020
+
Una de las funcionalidades que a muchos les causa confusión es la de usar hooks en React. Los hooks son una característica que nos ayuda a seguir implementando componentes en React.js usando la misma estructura de función. Uno de los hooks más conocidos es el hook de estado
useState().En este tutorial vamos a ver dónde y cuándo debemos utilizar el hook de estado en nuestras aplicaciones con React.
1. Para qué sirve useState()
useState() es la forma de utilizar el estado en componentes basados en funciones. Si nosotros estamos desarrollando nuestros componentes con clases tenemos algo como lo siguiente:class MiComponente extends React.Component{
constructor(props){
super(props);
this.state = {nombre: ''};
}
handleChange = e =>{
this.setState({nombre: e.target.value});
}
render(){
return(
<input onChange={this.handleChange()} value={this.state.nombre} />
);
}
}
this.state y this.setState() para poder manipular los datos en nuestro componente. Si lo queremos ver así es un getter y un setter. Sin embargo, para hacer lo mismo en un componente basado en función necesitamos hacer uso de el hook de estado.2. ¿Cómo funciona el hook de estado?
El mismo ejemplo anterior hecho con clase podemos hacerlo con funciones de la siguiente forma:import {React, useState} from 'react';
function MiComponente(props){
const [nombre, setNombre] = useState('');
function handleChange(e){
setNombre(e.target.value);
}
return(
<input onChange={handleChange()} value={nombre} />
);
}
useState() lo que nos permite hacer es hacer una desestructuración de una variable y una función. en nuestro caso la variable o estado que definimos es nombre y por lo tanto el siguiente parámetro es una función setNombre() para poder cambiar el valor de nombre. De la misma forma que cuando usamos clases tenemos que usar la función setState() para poder modificar el valor de nuestro estado, cuando usamos funciones usamos la función que definimos en la desestructuración para hacer dicho cambio.3. ¿Se pueden declarar más variables usando useState()?
La respuesta es que sí. A diferencia de cuando usamosstate y setState() para almacenar todos los estados de nuestos datos, usando useState() nos permite definir variables de forma independiente, lo cual puede ocasionar una forma más ágil de manipular los estados de los datos al tener una referencia mucho más visual de qué dato estás modificando con el nombre de la función.Conclusiones
Así funciona el hook de estado. Si ven la diferencia en realidad no hay ninguna, más que el mismo hecho de tener una variable y función para sustituir elstate y setState que ocupamos cuando lo hacemos con componentes basados en clases.Bonus
También pueden ver en este video la explicación del hook de estado en React.js y aprovechar para suscribirse a mi canal si no lo han hecho 😊
+
+
+
+ Clojurists Together is Funding Clojars
+News on Clojurists Together 23 04 2020
+
+
+
+ Ethical marketing in the GDPR, CCPA and no third-party cookies world
+Marko Saric 23 04 2020
+
+
+ Q2 2020 Funding Announcement
+News on Clojurists Together 23 04 2020
+
+
+ The Quest for the Perfect Dark Mode
+Josh Comeau's blog 22 04 2020
+
+ 
+
+
+ Startup Struggles
+MonkeyUser 21 04 2020
+
+ 
+
+
+ Return of the Weekly
+Instapaper 17 04 2020
+We’re excited to announce the return of the Instapaper Weekly, a Sunday morning email with the most popular Instapaper articles from the previous week. The articles are chosen based on the Instarank algorithm, which takes into account the number of saves, reads, and likes on articles from each day. The Weekly also includes the most popular highlight from the past week.
The Weekly was initially disabled in 2018 as we worked toward GDPR compliance. Around the same time, our email service changed their business model from volume-based to tier-based. The result was that it would cost more than twice as much to send the weekly email, which we could no longer afford as it would have significantly increased our operating costs.
While the Weekly has been disabled, it’s become one of the most frequently requested Instapaper features. Over the course of the past few months, we’ve done the work to migrate our email service provider from Mailgun to Amazon’s Simple Email Service (SES). SES has a volume-based pricing model, which allows us to send the Weekly in a cost-effective manner.
We wrote a more technical post about the migration from Mailgun to SES, which you can read here if you’re interested, and we open sourced some tools we made during the migration.
If you were previously receiving the Weekly, you should start seeing it in your inbox automatically. If you aren’t sure of your Weekly status or want to modify any email settings, please check your Settings page on web.
If you have any questions, feature requests, or issues you’d like us to sort out, please let us know at support@instapaper.com or @InstapaperHelp on Twitter.
Thanks for using Instapaper!
+
+
+
+
+ Lanzar tu plataforma e-Learning en tiempo record con Javier Pérez
+República Web 17 04 2020
+El e-learning está forzosamente de moda estos días. Aunque muchas organizaciones ya han hecho de la formación a distancia son modelo de negocio, otras han tenido que adaptarse con rapidez. El e-Learning es un concepto tan antiguo como la propia web y existen diferentes opciones para montar tus propios espacios de formación. Para este episodio hemos invitado a Javier Pérez Torres, responsable de la empresa española evolMind, especializada en soluciones de formación online en la nube, bajo un modelo SaaS. Su producto evolCampus es un desarrollo propio orientado a crear una plataforma de e-learning personalizable, integrada con multitud de servicios externos y todo bajo una sencilla interfaz.
+Con Javier Pérez hablamos sobre la solución que cubre evolCampus, la situación actual del mundo e-learning y la evolución de este tipo de herramientas. Entre todas las cuestiones tratadas destacamos:
+-
+
- Origen de la empresa y las tecnologías usadas en el proyecto. +
- Tipo de clientes que usan evolCampus. +
- Funcionalidades del servicio: SCORM, Integración con FUNDAE/SEPE, Zoom y otras plataformas de videoconferencia, Woocommerce y pagos. +
- Tipos de contenidos y actividades. +
- Seguimiento de actividades y alumnos. +
- Modelo de precios y futuro de software e-Learning. +
En definitiva una entrevista muy completa con una empresa española, que íntegramente desde Zaragoza desarrolla una completa solución de e-Learning bajo un modelo SaaS.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ Async
+MonkeyUser 14 04 2020
+
+
+ CSS Variables for React Devs
+Josh Comeau's blog 13 04 2020
+
+
+ The Algebraic Structure of Functions, illustrated using React components
+James Sinclair 13 04 2020
+
+
+ The Algebraic Structure of Functions, illustrated using React components
+Web Development - James Sinclair 13 04 2020
+
+
+
+
+ No Code, desarrolla tus proyectos web sin necesidad de código
+República Web 11 04 2020
+La tendencia hacia servicios que nos permiten desarrollar proyectos web sin necesidad de saber código cada vez más es más fuerte. La etiqueta No Code hace referencia a unas herramientas que nos permiten diseñar y desarrollar soluciones web, sin necesidad de tener conocimientos de programación. Son servicios asequibles, con una interfaz intuitiva y en muchos casos con elevada capacidad de personalización.
+En este episodio hablar de algunas de estas herramientas, las ventajas que aportan y los inconvenientes que pueden tener. Entre otras comentamos:
+-
+
- Webflow, Landen, Notion, WordPress, Squarespace, WIX, Shopify. +
- Airtable, integraciones Google Sheets. +
- Automizaciones y flujos de trabajo: Zapier, Mautic, IFTTT o Integromat. +
- Creación de Apps, Glide App / Dropsource / Adalo +
- Voiceflow, crear skills Alexa o Google. +
- Typeform, Substack, Pico. +
Hablamos sobre las ventajas que nos ofrecen este tipo de servicios y su capacidad de ser integradas a través de sus API. Además también hablamos sobre las desventajas que tiene derivar nuestros proyectos a servicios propietarios y que exigen cierta dependencia a la hora de extender, migrar o combinar servicio. También hablamos de la importancia de conocer el funcionamiento interno de nuestras herramientas y cómo con el tiempo se tiende a tener cierto control de nuestro código.
+En la última parte del episodio hablamos de recursos recomendados en diferentes materiales. Enlaces abajo.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ A Static Future
+Josh Comeau's blog 08 04 2020
+
+
+ Custom Djula filters
+Lisp journey 08 04 2020
+Djula is a Common Lisp port of +the Django templating language. It’s good, it’s proven (it’s one of +the most downloaded Quicklisp packages), it is easy to use and it has good +documentation.
+ +It basically looks like this:
+ + {% extends "base.html" %}
+ {% block title %}Memberlist{% endblock %}
+ {% block content %}
+ <ul>
+ {% for user in users %}
+ <li><a href="{{ user.url }}">{{ user.username }}</a></li>
+ {% endfor %}
+ </ul>
+ {% endblock %}
+What was missing in the documentation was how to create custom +filters. Here’s how, and it’s very simple.
+ +def-filter
+ +Use the def-filter macro. Its general form is:
(def-filter :myfilter-name (value arg)
+ (body))
+It always takes the variable’s value as argument, and it can have one +required or optional argument. For example, this is how those +built-in filters are defined:
+ +(def-filter :capfirst (val)
+ (string-capitalize (princ-to-string val)))
+This is all there is to it. Once written, you can use it in your +templates. You can define a filter wherever you want and there is no +need to register it or to import it in your templates.
+ +Here’s a filter with a required argument:
+ +(def-filter :add (it n)
+ (+ it (parse-integer n)))
+and with an optional one:
+ +(def-filter :datetime (it &optional format)
+ (let ((timestamp …))))
+When you need to pass a second argument, make your filter return a
+lambda function and chain it with the with filter:
(def-filter :replace (it regex)
+ (lambda (replace)
+ (ppcre:regex-replace-all regex it replace)))
+
+ (def-filter :with (it replace)
+ (funcall it replace))
+Now we can write::
+ +{{ value | replace:foo | with:bar }}
+Note: we should most probably be able to define filters with two +arguments. There’s an open issue about that.
+ +Error handling
+ +Errors are handled by the macro, but you can handle them and return a
+template-error condition:
(def-filter :handle-error-filter (it)
+ (handler-case
+ (do-something)
+ (condition (e)
+ (template-error "There was an error executing this filter: ~A" e))))
+It will be rendered on the browser with a nice stacktrace.
+ +Final words
+ +If you don’t know what template engine to use for your web project,
+start with it. My only criticism is that accessing variables is not
+totally flexible. The {{ obj.val }} syntax already works to access
+objects’ slots, alists, plists, hash-tables and whatnot (it uses the
+excellent
+Access
+library), but it won’t work for some data (like structures), forcing
+you to a bit of pre-processing before rendering the template. And you
+can’t use much logic with template tags. However, this is by
+design. Djula is a port of the Django templating engine after all.
For more flexible templates and still write html (because, you know, we can copy-paste examples easily!), see Eco. See more templates engines in the Awesome-cl list.
+ +Last-minute addition: while I was writing this, Djula’s author released TEN, another templating engine, combining the best of Djula and Eco.
+ + + +
+
+ March 2020 Monthly Update
+News on Clojurists Together 08 04 2020
+
+
+ Advantages of Data Oriented Programming
+(iterate think thoughts) 08 04 2020
+One of the biggest advantages I've found working with Clojure is its data oriented nature. Ultimately, all that code is doing is transform data. A program starts with one piece of data as the input and produces another as its output. Mainstream languages attempt to abstract over that using object oriented semantics. While practical value of such abstraction is not entirely clear, there are some tangible problems associated with this approach. Let's take a look at some drawbacks to structuring programs using OO style.
Traditionally, an object can be thought of as a type of a state machine that contains some data fields representing its internal state and provides some methods for manipulating it. An object represents the smallest compositional unit in OO, and a program is structured as a graphs of such objects that interact with one another by manipulating each others state.
The first problem we have is that each object is an ad hoc DSL. When a developer designs an object they define its API in form of methods and come up with the behaviors the object will have. This makes each object unique, and knowing how one object behaves tells you nothing regarding how the next object might behave. Rich Hickey illustrates this point in detail in his Clojure, Made Simple talk. The more objects you define the more behaviors you have to keep in your head. Thus, cognitive overhead grows proportionally with the size of the program.
Any mutable objects present in the program require the developer to know the state of the objects in order to know how the program will behave. A program that is structured as a graph of interdependent state machines quickly becomes impossible to reason about. The problem stems from objects being implicitly connected via references to each other resulting in shared mutable state. This leads to lack or referential transparency and makes it impossible to do local reasoning about the code. In order to tell what a piece of code is doing you also have to track down all the code that shares references with the code you're reading.
This is one reason why sophisticated debugging tools are needed to work with code effectively in object oriented languages. The only way to tell what's happening in a large program is to run it in a debugger, try to put it in a particular state and then inspect it. Unfortunately, this approach is just a heuristic since there may be many different paths that get you to a particular state, and it's impossible to guarantee that you've covered them all.
Another notable problem with objects is that there is no standard way for serializing them creating additional pain at program boundaries. For example, we can't just take an object graph on from a web server and send it to the client. We must write custom serializers for every object adding complexity and boilerplate to our programs. A related problem occurs when composing libraries that define their own classes leading to prevalence of wrapper and adapter patterns.
All these problems disappear in a data oriented language like Clojure. Modern FP style embraces the fact that programs can be viewed as data transformation pipelines where input data is passed through a series of pure functions to transform it into desired output. Such functions can be reasoned about in isolation without having to consider the rest of the program. Plain data doesn't have any hidden behaviors or state that you have to worry about. Immutable data is both transparent and inert while objects are opaque and stateful.
As a concrete example, Pedestal HTTP server has around 18,000 lines of code, and 96% of it is pure functions. All the IO and side effects are encapsulated in the remaining 4% of the code. This has been a common scenario for the vast majority of Clojure programs I've worked on.
Cognitive overhead associated with reasoning about code is localized as opposed to being directly influenced by the size of the application as often happens with OO. Each function can be thought of as an small individual program, and we simply pipe these programs together to solve bigger problems. Incidentally, this is the exact same approach as advocated by Ken Thompson in Unix philosophy.
Data can also be passed across program boundaries since it's directly serializable. A Clojure web server can send its output directly to the client, and client code can operate on this data without any additional ceremony. I've discussed some of the practical benefits that stem from having standard serialization semantics in this presentation.
Another advantage of separating data from logic is code reuse. A pure function that transforms one piece of data into another can be used in any context. A common set of functions from the standard library can be used to manipulate data regardless where it comes from. Once you learn a few common patterns for transforming data, you can apply these patterns everywhere.
I strongly suspect that data driven APIs are a major reason why Clojure libraries tend to be so stable. When a library is simply transforming data then it's possible to get to a state where it's truly done. Once the API consisting of all the supported transformations has been defined and tested, then the API is complete. The only times the library has to be revisited is when use cases missed by tests are discovered or new features are added. This tends to happen early on during library lifecycle, and hence mature libraries need little attention from their maintainers.
Of course, this is not to say that large software cannot be written effectively using OO languages. Clearly plenty of great software has been produced using these techniques. However, the fact that complex applications can be written in a particular fashion is hardly interesting of itself. Given enough dedication and ingenuity it's possible to write complex software in any language. It's more useful to consider how different approaches impact development style in different languages.
+
+
+ How to Provide Test Fixtures for Django Models in Pytest
+Haki Benita 07 04 2020
+One of the most challenging aspects of writing good tests is maintaining test fixtures. Good test fixtures motivate developers to write better tests, and bad fixtures can cripple a system to a point where developers fear and avoid them all together. The article covers everything from setting up Pytest for a Django project, creating test fixtures and how to create dependency between fixtures.
+
+
+ Styling Ordered Lists with CSS Counters
+Josh Comeau's blog 07 04 2020
+
+ 
+
+
+ Err
+MonkeyUser 07 04 2020
+
+
+
+ Use Firefox Preview to make browsing on Android fast and distraction-free
+Marko Saric 06 04 2020
+
+
+ How to Use a Differential Analyzer (to Murder People)
+Two-Bit History 06 04 2020
+
+
+
+ How to fight back against Google AMP
+Marko Saric 05 04 2020
+
+
+
+
+ Google trackeando y yo con MAZA bloqueando
+República Web 04 04 2020
+Aprovechando la reciente repercusión del ad blocker realizado por Andros llamado Maza en Hacker News y en blogs de referencia, hablamos en el episodio sobre tecnologías de bloqueo de anuncios. La tendencia a la instalación de soluciones para bloquear anuncios por parte de los usuarios sigue en aumento, en especial en los móviles. Esto también coincide con la incorporación de navegadores con bloqueadores nativos como Brave, extensiones para navegadores, software para móviles y aplicaciones de escritorios, VPN y soluciones basadas en DNS.
+Por eso en ese episodio queremos hablar sobre las diferentes alternativas que existen para bloquear anuncios, su funcionamiento y cómo todo esto está influyendo en los proveedores de contenido en internet.
+++Maza – Local ad blocker. Like Pi-hole but local and using your operating system. Only works on Linux and macOS.https://t.co/bnHlR8DERA
+— The Best Linux Blog In the Unixverse (@nixcraft) March 29, 2020
+
Hablamos de soluciones de bloqueo de anuncios en el navegador con extensiones para el navegador de escritorio como uBlock Origin, navegadores nativos como Brave y otras soluciones a nivel de navegador en Firefox o en Opera. También vemos programas para bloquear los anuncios a nivel de dispositivo con programas como AdGuard o proveedores VPN como Private Internet Access. También soluciones DNS y de hardware como Pi-Hole, NextDNS, Cloudfare o la propia solución de Andros MAZA.
+También hablamos de la dinámica en el ecosistema de anuncios online, como los proveedores de programática y soluciones de monetización como Relevant ads. Comentamos también la iniciativa de Firefox Better Web con Scroll, un servicio para remunerar a creadores de contenido asociados, con una membresía mensual.
+Por último en la sección de Radar ofrecemos una colección de recursos interesantes para el desarrollo web y profesional.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Calculator in Vim – The Expression register
+Jovica Ilic 04 04 2020
+As a software developer you probably have to perform actions like copying different pieces of your code from multiple files into different locations of your current Vim session. Using only system clipboard, this can be a cumbersome and time consuming task. Once you master Vim registers, your text editing efficiency will greatly improve. A register... Continue reading
+The post Calculator in Vim – The Expression register appeared first on Jovica Ilic.
+ +
+
+ Q2 2020 Survey Results
+News on Clojurists Together 03 04 2020
+
+
+ Using Markdown in Django
+Haki Benita 29 03 2020
+How we developed a Markdown extension to manage content in Django sites.
+
+
+ Learning to Learn Effectively – Tip #1
+Jovica Ilic 29 03 2020
+In this post, I’ll share with you one of my favorite learning tip. This tip will help you greatly improve your learning skills. It can be also useful for giving more powerful presentations. It comes from the bonus ebook Learning to Learn Effectively from my Premium package of Mastering Vim Quickly. … If you knew you had a... Continue reading
+The post Learning to Learn Effectively – Tip #1 appeared first on Jovica Ilic.
+ +
+
+
+
+ Estudio sobre uso de bases de datos relacionales y NoSQL
+República Web 28 03 2020
+Estamos de vuelta con el estudio de David Vaquero sobre el uso de tecnologías web y esta vez tratamos las bases de datos. En su propio estudio David analiza el uso de tecnologías de bases de datos sobre el millón de sitios web proporcionado por Alexa, tomando además dominios españoles. Este trabajo nos sirve para comentar los resultados y explicar las diferencias entre las bases de datos relacionales como MySQL, Percona, MariaDB o PostgreSQL y las basadas en las llamadas noSQL, con MongoDB como principal protagonista y claramente orientadas a soluciones distribuidas y escalables.
+En el episodio David explica con detalle las diferencias conceptuales de este tipo de base de datos y los usos a los que va dirigidos. Es una explicación muy útil para tener una idea global sobre estas tecnologías y lo crítico que puede resultar para el rendimiento y la escalabilidad de nuestros proyectos.
+Tradicionalmente las bases de datos se han visto como una caja negra, con una abstracción muy elevada para evitar preocuparse en los detalles de acceso y manipulación de los datos. Esta abstracción libera a los profesionales de las complejidades del software, aunque la exigencia y naturaleza de ciertas aplicaciones requieren tener un control más exhaustivo de cómo funcionan, destacando la importancia de contar con profesionales que optimicen los sistemas.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ GUI Programming in Common Lisp, part 5/5: Nuklear
+Lisp journey 27 03 2020
+Nuklear is a small immediate-mode GUI toolkit:
+ +++ +Nuklear is a minimal-state, immediate-mode graphical user interface toolkit written in ANSI C and licensed under public domain. It was designed as a simple embeddable user interface for application and does not have any dependencies, a default render backend or OS window/input handling but instead provides a highly modular, library-based approach, with simple input state for input and draw commands describing primitive shapes as output. So instead of providing a layered library that tries to abstract over a number of platform and render backends, it focuses only on the actual UI.
+
its Lisp binding is Bodge-Nuklear, and its higher level companions bodge-ui and bodge-ui-window.
+ +Unlike traditional UI frameworks, Nuklear allows the developer to take +over the rendering loop or the input management. This might require +more setup, but it makes Nuklear particularly well suited for games, +or for applications where you want to create new controls.
+ +Previous posts of the serie:
+ + + +This blog post series was initially written for the Common Lisp +Cookbook, you can (and should) read it there:
+ +https://lispcookbook.github.io/cl-cookbook/gui.html
+ +-
+
- Framework written in: ANSI C, single-header library. + +
Portability: where C runs. Nuklear doesn’t contain +platform-specific code. No direct OS or window handling is done in +Nuklear. Instead all input state has to be provided by platform +specific code.
+
+Widgets choice: small.
+
+Graphical builder: no.
+
+Other features: fully skinnable and customisable.
+
+Bindings stability: stable
+
+Bindings activity: active
+
+Licence: MIT or Public Domain (unlicence).
+
+Example applications:
+ +-
+
- Trivial-gamekit +
- Obvius - a resurrected image processing library. +
- Notalone - an autumn 2017 Lisp Game Jam entry. +
+
List of widgets
+ +Non-exhaustive list:
+ +buttons, progressbar, image selector, (collapsable) tree, list, grid, range, slider, color picker,
+date-picker
+
Getting started
+ +Disclaimer: as per the author’s words at the time of writing, +bodge-ui is in early stages of development and not ready for general +use yet. There are some quirks that need to be fixed, which might +require some changes in the API.
+ +bodge-ui is not in Quicklisp but in its own Quicklisp distribution. Let’s install it:
(ql-dist:install-dist "http://bodge.borodust.org/dist/org.borodust.bodge.txt" :replace t :prompt nil)
+Uncomment and evaluate this line only if you want to enable the OpenGL 2 +renderer:
+ +;; (cl:pushnew :bodge-gl2 cl:*features*)
+Quickload bodge-ui-window:
(ql:quickload :bodge-ui-window)
+We can run the built-in example:
+ +(ql:quickload :bodge-ui-window/examples)
+(bodge-ui-window.example.basic:run)
+Now let’s define a package to write a simple application.
+ +(cl:defpackage :bodge-ui-window-test
+ (:use :cl :bodge-ui :bodge-host))
+(in-package :bodge-ui-window-test)
+(defpanel (main-panel
+ (:title "Hello Bodge UI")
+ (:origin 200 50)
+ (:width 400) (:height 400)
+ (:options :movable :resizable
+ :minimizable :scrollable
+ :closable))
+ (label :text "Nested widgets:")
+ (horizontal-layout
+ (radio-group
+ (radio :label "Option 1")
+ (radio :label "Option 2" :activated t))
+ (vertical-layout
+ (check-box :label "Check 1" :width 100)
+ (check-box :label "Check 2"))
+ (vertical-layout
+ (label :text "Awesomely" :align :left)
+ (label :text "Stacked" :align :centered)
+ (label :text "Labels" :align :right)))
+ (label :text "Expand by width:")
+ (horizontal-layout
+ (button :label "Dynamic")
+ (button :label "Min-Width" :width 80)
+ (button :label "Fixed-Width" :expandable nil :width 100))
+ )
+
+(defun run ()
+ (bodge-host:open-window (make-instance 'main-window)))
+and run it:
+ +(run)
+
To react to events, use the following signals:
+ +:on-click
+:on-hover
+:on-leave
+:on-change
+:on-mouse-press
+:on-mouse-release
+They take as argument a function with one argument, the panel. But +beware: they will be called on each rendering cycle when the widget is +on the given state, so potentially a lot of times.
+ +Interactive development
+ +If you ran the example in the REPL, you couldn’t see what’s cool. Put +the code in a lisp file and run it, so than you get the window. Now +you can change the panel widgets and the layout, and your changes will +be immediately applied while the application is running!
+ +Conclusion
+ +Have fun, don’t hesitate to share your experience and your apps… and contribute to the Cookbook!
+ +
+ 
+
+
+ GUI Programming in Common Lisp, part 4/5: IUP
+Lisp journey 27 03 2020
+IUP is a cross-platform GUI toolkit actively developed +at the PUC university of Rio de Janeiro, Brazil. It uses native +controls: the Windows API for Windows, Gtk3 for GNU/Linux. At the +time of writing, it has a Cocoa port in the works (as well as iOS, +Android and WASM ones). A particularity of IUP is its small API.
+ +The Lisp bindings are lispnik/iup. They are nicely +done in that they are automatically generated from the C sources. They +can follow new IUP versions with a minimal work and the required steps +are documented. All this gives us good guarantee over the bus +factor.
+ +IUP stands as a great solution in between Tk and Gtk or Qt.
+ +Previous posts of the serie:
+ + + +This blog post series was initially written for the Common Lisp +Cookbook, you can (and should) read it there:
+ +https://lispcookbook.github.io/cl-cookbook/gui.html
+ +-
+
- Framework written in: C (official API also in Lua and LED) + +
Portability: Windows and Linux, work started for +Cocoa, iOS, Android, WASM.
+
+Widgets choice: medium.
+
+Graphical builder: yes: IupVisualLED
+
+Other features: OpenGL, Web browser (WebKitGTK on GNU/Linux), plotting, Scintilla text editor
+
+Bindings documentation: good examples and good readme, otherwise low.
+
+Bindings stability: alpha (but fully generated and working nicely)
+
+Bindings activity: low
+
+Licence: IUP and the bindings are MIT licenced.
+
List of widgets
+ +Radio, Tabs, FlatTabs, ScrollBox, DetachBox,
+Button, FlatButton, DropButton, Calendar, Canvas, Colorbar, ColorBrowser, DatePick, Dial, Gauge, Label, FlatLabel,
+FlatSeparator, Link, List, FlatList, ProgressBar, Spin, Text, Toggle, Tree, Val,
+listDialog, Alarm, Color, Message, Font, Scintilla, file-dialog…
+Cells, Matrix, MatrixEx, MatrixList,
+GLCanvas, Plot, MglPlot, OleControl, WebBrowser (WebKit/Gtk+)…
+drag-and-drop
+
Getting started
+ +Please check the installation instructions upstream. You may need one +system dependency on GNU/Linux, and to modify an environment variable +on Windows.
+ +Finally, do:
+ +(ql:quickload :iup)
+We are not going to :use IUP (it is a bad practice generally after all).
(defpackage :test-iup
+ (:use :cl))
+(in-package :test-iup)
+The following snippet creates a dialog frame to display a text label.
+ +(defun hello ()
+ (iup:with-iup ()
+ (let* ((label (iup:label :title (format nil "Hello, World!~%IUP ~A~%~A ~A"
+ (iup:version)
+ (lisp-implementation-type)
+ (lisp-implementation-version))))
+ (dialog (iup:dialog label :title "Hello, World!")))
+ (iup:show dialog)
+ (iup:main-loop))))
+(hello)
+Important note for SBCL: we currently must trap division-by-zero +errors (see advancement on this +issue). So, run snippets +like so:
+ +(defun run-gui-function ()
+ #-sbcl (gui-function)
+ #+sbcl
+ (sb-int:with-float-traps-masked
+ (:divide-by-zero :invalid)
+ (gui-function)))
+How to run the main loop
+ +As with all the bindings seen so far, widgets are shown inside a
+with-iup macro, and with a call to iup:main-loop.
How to create widgets
+ +The constructor function is the name of the widget: iup:label,
+iup:dialog.
How to display a widget
+ +Be sure to “show” it: (iup:show dialog).
You can group widgets on frames, and stack them vertically or
+horizontally (with vbox or hbox, see the example below).
To allow a widget to be expanded on window resize, use :expand
+:yes (or :horizontal and :vertical).
Use also the :alignement properties.
How to get and set a widget’s attributes
+ +Use (iup:attribute widget attribute) to get the attribute’s value,
+and use setf on it to set it.
Reacting to events
+ +Most widgets take an :action parameter that takes a lambda function
+with one parameter (the handle).
(iup:button :title "Test &1"
+ :expand :yes
+ :tip "Callback inline at control creation"
+ :action (lambda (handle)
+ (iup:message "title" "button1's action callback")
+ iup:+default+))
+Below we create a label and put a button below it. We display a +message dialog when we click on the button.
+ +(defun click-button ()
+ (iup:with-iup ()
+ (let* ((label (iup:label :title (format nil "Hello, World!~%IUP ~A~%~A ~A"
+ (iup:version)
+ (lisp-implementation-type)
+ (lisp-implementation-version))))
+ (button (iup:button :title "Click me"
+ :expand :yes
+ :tip "yes, click me"
+ :action (lambda (handle)
+ (declare (ignorable handle))
+ (iup:message "title" "button clicked")
+ iup:+default+)))
+ (vbox
+ (iup:vbox (list label button)
+ :gap "10"
+ :margin "10x10"
+ :alignment :acenter))
+ (dialog (iup:dialog vbox :title "Hello, World!")))
+ (iup:show dialog)
+ (iup:main-loop))))
+
+#+sbcl
+(sb-int:with-float-traps-masked
+ (:divide-by-zero :invalid)
+ (click-button))
+Here’s a similar example to make a counter of clicks. We use a label +and its title to hold the count. The title is an integer.
+ +(defun counter ()
+ (iup:with-iup ()
+ (let* ((counter (iup:label :title 0))
+ (label (iup:label :title (format nil "The button was clicked ~a time(s)."
+ (iup:attribute counter :title))))
+ (button (iup:button :title "Click me"
+ :expand :yes
+ :tip "yes, click me"
+ :action (lambda (handle)
+ (declare (ignorable handle))
+ (setf (iup:attribute counter :title)
+ (1+ (iup:attribute counter :title 'number)))
+ (setf (iup:attribute label :title)
+ (format nil "The button was clicked ~a times."
+ (iup:attribute counter :title)))
+ iup:+default+)))
+ (vbox
+ (iup:vbox (list label button)
+ :gap "10"
+ :margin "10x10"
+ :alignment :acenter))
+ (dialog (iup:dialog vbox :title "Counter")))
+ (iup:show dialog)
+ (iup:main-loop))))
+
+(defun run-counter ()
+ #-sbcl
+ (counter)
+ #+sbcl
+ (sb-int:with-float-traps-masked
+ (:divide-by-zero :invalid)
+ (counter)))
+List widget example
+ +Below we create three list widgets with simple and multiple selection, we +set their default value (the pre-selected row) and we place them +horizontally side by side.
+ +(defun list-test ()
+ (iup:with-iup ()
+ (let* ((list-1 (iup:list :tip "List 1" ;; tooltip
+ ;; multiple selection
+ :multiple :yes
+ :expand :yes))
+ (list-2 (iup:list :value 2 ;; default index of the selected row
+ :tip "List 2" :expand :yes))
+ (list-3 (iup:list :value 9 :tip "List 3" :expand :yes))
+ (frame (iup:frame
+ (iup:hbox
+ (progn
+ ;; populate the lists: display integers.
+ (loop for i from 1 upto 10
+ do (setf (iup:attribute list-1 i)
+ (format nil "~A" i))
+ do (setf (iup:attribute list-2 i)
+ (format nil "~A" (+ i 10)))
+ do (setf (iup:attribute list-3 i)
+ (format nil "~A" (+ i 50))))
+ ;; hbox wants a list of widgets.
+ (list list-1 list-2 list-3)))
+ :title "IUP List"))
+ (dialog (iup:dialog frame :menu "menu" :title "List example")))
+
+ (iup:map dialog)
+ (iup:show dialog)
+ (iup:main-loop))))
+
+(defun run-list-test ()
+ #-sbcl (hello)
+ #+sbcl
+ (sb-int:with-float-traps-masked
+ (:divide-by-zero :invalid)
+ (list-test)))
+Next is a different toolkit very well suited for games and that enables fully interactive development: Nuklear.
+ +
+ 
+
+
+ GUI Programming in Common Lisp, part 3/5: Gtk3
+Lisp journey 27 03 2020
+We continue our tour of GUI toolkits for CL with Gtk+3 and cl-cffi-gtk.
+ +The previosu posts are:
+ + + +This blog post series was initially written for the Common Lisp +Cookbook, you can (and should) read it there:
+ +https://lispcookbook.github.io/cl-cookbook/gui.html
+ +Gtk+3 (cl-cffi-gtk)
+ +Gtk+3 is the primary library used to build GNOME +applications. Its (currently most advanced) lisp bindings is +cl-cffi-gtk. While primarily created for GNU/Linux, Gtk +works fine under macOS and can now also be used on Windows.
+ +-
+
- Framework written in: C + +
Portability: GNU/Linux and macOS, also Windows.
+
+Widgets choice: large.
+
+Graphical builder: yes: Glade.
+
+Other features: web browser (WebKitGTK)
+
+Bindings documentation: very good: http://www.crategus.com/books/cl-gtk/gtk-tutorial.html
+
+Bindings stability: stable
+
+Bindings activity: low activity, active development.
+
+Licence: LGPL
+
+Example applications:
+ +-
+
- an Atmosphere Calculator, built with Glade. +
+
Getting started
+ +The +documentation +is exceptionally good, including for beginners.
+ +The library to quickload is cl-cffi-gtk. It is made of numerous
+ones, that we have to :use for our package.
(ql:quickload :cl-cffi-gtk)
+
+(defpackage :gtk-tutorial
+ (:use :gtk :gdk :gdk-pixbuf :gobject
+ :glib :gio :pango :cairo :common-lisp))
+
+(in-package :gtk-tutorial)
+How to run the main loop
+ +As with the other libraries, everything happens inside the main loop
+wrapper, here with-main-loop.
How to create a window
+ +(make-instance 'gtk-window :type :toplevel :title "hello" ...).
How to create a widget
+ +All widgets have a corresponding class. We can create them with
+make-instance 'widget-class, but we preferably use the constructors.
The constructors end with (or contain) “new”:
+ +(gtk-label-new)
+(gtk-button-new-with-label "Label")
+How to create a layout
+ +(let ((box (make-instance 'gtk-box :orientation :horizontal :spacing 6))) ...)
+then pack a widget onto the box:
+ +(gtk-box-pack-start box mybutton-1)
+and add the box to the window:
+ +(gtk-container-add window box)
+and display them all:
+ +(gtk-widget-show-all window)
+Reacting to events
+ +Use g-signal-connect + the concerned widget + the event name (as a
+string) + a lambda, that takes the widget as argument:
(g-signal-connect window "destroy"
+ (lambda (widget)
+ (declare (ignore widget))
+ (leave-gtk-main)))
+Or again:
+ +(g-signal-connect button "clicked"
+ (lambda (widget)
+ (declare (ignore widget))
+ (format t "Button was pressed.~%")))
+Full example
+ +(defun hello-world ()
+ ;; in the docs, this is example-upgraded-hello-world-2.
+ (within-main-loop
+ (let ((window (make-instance 'gtk-window
+ :type :toplevel
+ :title "Hello Buttons"
+ :default-width 250
+ :default-height 75
+ :border-width 12))
+ (box (make-instance 'gtk-box
+ :orientation :horizontal
+ :spacing 6)))
+ (g-signal-connect window "destroy"
+ (lambda (widget)
+ (declare (ignore widget))
+ (leave-gtk-main)))
+ (let ((button (gtk-button-new-with-label "Button 1")))
+ (g-signal-connect button "clicked"
+ (lambda (widget)
+ (declare (ignore widget))
+ (format t "Button 1 was pressed.~%")))
+ (gtk-box-pack-start box button))
+ (let ((button (gtk-button-new-with-label "Button 2")))
+ (g-signal-connect button "clicked"
+ (lambda (widget)
+ (declare (ignore widget))
+ (format t "Button 2 was pressed.~%")))
+ (gtk-box-pack-start box button))
+ (gtk-container-add window box)
+ (gtk-widget-show-all window))))
+
Next is IUP, a not very famous but really great toolkit!
+ +
+ 
+
+
+ GUI Programming in Common Lisp, part 2/5: Qt4 with Qtools
+Lisp journey 27 03 2020
+Here’s the second part of our exploration of GUI toolkits for Common Lisp.
+ +The first part and introduction is accessible here:
+ +-
+
- part 1: Ltk +
This blog post series was initially written for the Common Lisp +Cookbook, you can (and should) read it there:
+ +https://lispcookbook.github.io/cl-cookbook/gui.html
+ +Qt4 (Qtools)
+ +Do we need to present Qt and Qt4? Qt is huge and contains +everything and the kitchen sink. Qt not only provides UI widgets, but +numerous other layers (networking, D-BUS…).
+ +Qt is free for open-source software, however you’ll want to check the +conditions to ship proprietary ones.
+ +The Qtools bindings target Qt4. The Qt5 Lisp bindings are +yet to be created.
+ + + +-
+
- Framework written in: C++ +
- Framework Portability: multi-platform, Android, embedded systems, WASM. + +
Bindings Portability: Qtools runs on x86 desktop platforms on Windows, macOS and GNU/Linux.
+
+Widgets choice: large.
+
+Graphical builder: yes.
+
+Other features: Web browser, a lot more.
+
+Bindings documentation: lengthy explanations, a few examples. Prior Qt knowledge is required.
+
+Bindings stability: stable
+
+Bindings activity: active
+
+Qt Licence: both commercial and open source licences.
+
+Example applications:
+ +
+
Getting started
+ +(ql:quickload '(:qtools :qtcore :qtgui))
+(defpackage #:qtools-test
+ (:use #:cl+qt)
+ (:export #:main))
+(in-package :qtools-test)
+(in-readtable :qtools)
+We create our main widget that will contain the rest:
+ +(define-widget main-window (QWidget)
+ ())
+We create an input field and a button inside this main widget:
+ +(define-subwidget (main-window name) (q+:make-qlineedit main-window)
+ (setf (q+:placeholder-text name) "Your name please."))
+(define-subwidget (main-window go-button) (q+:make-qpushbutton "Go!" main-window))
+We stack them horizontally:
+ +(define-subwidget (main-window layout) (q+:make-qhboxlayout main-window)
+ (q+:add-widget layout name)
+ (q+:add-widget layout go-button))
+and we show them:
+ +(with-main-window
+ (window 'main-window))
+
That’s cool, but we don’t react to the click event yet.
+ +Reacting to events
+ +Reacting to events in Qt happens through signals and slots. Slots are +functions that receive or “connect to” signals, and signals are event carriers.
+ +Widgets already send their own signals: for example, a button sends a +“pressed” event. So, most of the time, we only need to connect to them.
+ +However, had we extra needs, we can create our own set of signals.
+ +Built-in events
+ +We want to connect our go-button to the pressed and
+return-pressed events and display a message box.
-
+
- we need to do this inside a
define-slotfunction,
+ - where we establish the connection to those events, +
- and where we create the message box. We grab the text of the
name+input field with(q+:text name).
+
(define-slot (main-window go-button) ()
+ (declare (connected go-button (pressed)))
+ (declare (connected name (return-pressed)))
+ (q+:qmessagebox-information main-window
+ "Greetings" ;; title
+ (format NIL "Good day to you, ~a!" (q+:text name))))
+And voilà. Run it with
+ +(with-main-window (window 'main-window))
+Custom events
+ +We’ll implement the same functionality as above, but for demonstration
+purposes we’ll create our own signal named name-set to throw when
+the button is clicked.
We start by defining the signal, which happens inside the
+main-window, and which is of type string:
(define-signal (main-window name-set) (string))
+We create a first slot to make our button react to the pressed
+and return-pressed events. But instead of creating the message box
+here, as above, we send the name-set signal, with the value of our
+input field..
(define-slot (main-window go-button) ()
+ (declare (connected go-button (pressed)))
+ (declare (connected name (return-pressed)))
+ (signal! main-window (name-set string) (q+:text name)))
+So far, nobody reacts to name-set. We create a second slot that
+connects to it, and displays our message. Here again, we precise the
+parameter type.
(define-slot (main-window name-set) ((new-name string))
+ (declare (connected main-window (name-set string)))
+ (q+:qmessagebox-information main-window "Greetings" (format NIL "Good day to you, ~a!" new-name)))
+and run it:
+ +(with-main-window (window 'main-window))
+Building and deployment
+ +It is possible to build a binary and bundle it together with all the +necessary shared libraries.
+ +Please read https://github.com/Shinmera/qtools#deployment.
+ +You might also like this Travis CI script to build a self-contained binary for the three OSes.
+ +Next, we’ll have a look at Gtk+3.
+ +
+ 
+
+
+ GUI Programming in Common Lisp, part 1/5: Tk
+Lisp journey 27 03 2020
+Lisp has a long and rich history and so does the development of +Graphical User Interfaces in Lisp. In fact, the first GUI builder was +written in Lisp (and sold to Apple. It is now Interface Builder).
+ +Lisp is also famous and unrivaled for its interactive development +capabilities, a feature even more worth having to develop GUI +applications. Can you imagine compiling one function and seeing your +GUI update instantly? We can do this with many GUI frameworks today, +even though the details differ from one to another.
+ +Finally, a key part in building software is how to build it and ship +it to users. Here also, we can build self-contained binaries, for +the three main operating systems, that users can run with a double +click.
+ +We aim here to give you the relevant information to help you choose +the right GUI framework and to put you on tracks. Don’t hesitate to +contribute, to +send more examples and to furnish the upstream documentations.
+ +This blog post series was initially written for the Common Lisp +Cookbook, you can (and should) read it there:
+ +https://lispcookbook.github.io/cl-cookbook/gui.html
+ +Introduction
+ +In this article series, we’ll present the following GUI toolkits:
+ +-
+
- Tk with Ltk +
- Qt4 with Qtools +
- IUP with lispnik/iup +
- Gtk3 with cl-cffi-gtk +
- Nuklear with Bodge-Nuklear +
In addition, you might want to have a look to:
+ +-
+
- the CAPI toolkit (Common Application Programming Interface), +which is proprietary and made by LispWorks. It is a complete and cross-platform +toolkit (Windows, Gtk+, Cocoa), very praised by its users. LispWorks +also has iOS and Android +runtimes. Example +software built with CAPI include Opusmodus +or again ScoreCloud. It is possible to +try it with the LispWorks free demo. +
- CocoaInterface, a +Cocoa interface for Clozure Common Lisp. Build Cocoa user interface +windows dynamically using Lisp code and bypass the typical Xcode +processes. +
- McCLIM, a toolkit in 100% Common Lisp. +
- Alloy, another very new toolkit in 100% Common Lisp, used for example in the Kandria game. +
- nodgui, a fork of Ltk, with syntax sugar and additional widgets. +
- eql, eql5, eql5-android, embedded Qt4 and Qt5 Lisp, embedded in ECL, embeddable in Qt. Port of EQL5 to the Android platform. +
- this demo using Java Swing from ABCL +
- and, last but not least, Ceramic, to ship a cross-platform web app with Electron. +
as well as the other ones listed on awesome-cl#gui and Cliki.
+ +Tk (Ltk)
+ +Tk (or Tcl/Tk, where Tcl is the programming language) has the +infamous reputation of having an outdated look. This is not (so) true +anymore since its version 8 of 1997 (!). It is probably better than +you think:
+ +
Tk doesn’t have a great choice of widgets, but it has a useful canvas, +and it has a couple of unique features: we can develop a graphical +interface fully interactively and we can run the GUI remotely +from the core app.
+ +So, Tk isn’t fancy, but it is an used and proven GUI toolkit (and +programming language) still used in the industry. It can be a great +choice to quickly create simple GUIs, to leverage its ease of deployment, or +when stability is required.
+ +The Lisp binding is Ltk.
+ +-
+
- Written in: Tcl + +
Portability: cross-platform (Windows, macOS, Linux).
+
+Widgets: this is not the fort of Tk. It has a small set of +default widgets, and misses important ones, for example a calendar. We +can find some in extensions (such as in Nodgui), but they don’t +feel native, at all.
+
+Interactive development: very much.
+
+Graphical builder: no
+
+Other features:
+ +-
+
- remote execution: the connection between Lisp and Tcl/Tk is +done via a stream. It is thus possible to run the Lisp program on +one computer, and to display the GUI on another one. The only +thing required on the client computer is tcl/tk installed and the +remote.tcl script. See Ltk-remote. +
+
+Bindings documentation: short but complete. Nodgui too.
+
+Bindings stability: very stable
+
+Bindings activity: low to non-existent.
+
+Licence: Tcl/Tk is BSD-style, Ltk is LGPL.
+
+Example applications:
+ +-
+
- Fulci - a program to organize your movie collections. +
- Ltk small games - snake and tic-tac-toe. +
- cl-torrents - searching torrents on popular trackers. CLI, readline and a simple Tk GUI. +
+
List of widgets
+ +(please don’t suppose the list exhaustive)
+ +Button Canvas Check-button Entry Frame Label Labelframe Listbox
+Menu Menubutton Message
+Paned-window
+Radio-button Scale
+Scrollbar Spinbox Text
+Toplevel Widget Canvas
+
+Ltk-megawidgets:
+ progress
+ history-entry
+ menu-entry
+Nodgui adds:
+ +treelist tooltip searchable-listbox date-picker calendar autocomplete-listbox
+password-entry progress-bar-star notify-window
+dot-plot bar-chart equalizer-bar
+swap-list
+Getting started
+ +Ltk is quick and easy to grasp.
+ +(ql:quickload :ltk)
+(in-package :ltk-user)
+How to create widgets
+ +All widgets are created with a regular make-instance and the widget name:
(make-instance 'button)
+(make-instance 'treeview)
+This makes Ltk explorable with the default symbol completion.
+ +How to start the main loop
+ +As with most bindings, the GUI-related code must be started inside a macro that
+handles the main loop, here with-ltk:
(with-ltk ()
+ (let ((frame (make-instance 'frame)))
+ …))
+How to display widgets
+ +After we created some widgets, we must place them on the layout. There
+are a few Tk systems for that, but the most recent one and the one we
+should start with is the grid. grid is a function that takes as
+arguments the widget, its column, its row, and a few optional
+parameters.
As with any Lisp code in a regular environment, the functions’ +signatures are indicated by the editor. It makes Ltk explorable.
+ +Here’s how to display a button:
+ +(with-ltk ()
+ (let ((button (make-instance 'button :text "hello")))
+ (grid button 0 0)))
+That’s all there is to it.
+ +Reacting to events
+ +Many widgets have a :command argument that accept a lambda which is
+executed when the widget’s event is started. In the case of a button,
+that will be on a click:
(make-instance 'button
+ :text "Hello"
+ :command (lambda ()
+ (format t "clicked")))
+Interactive development
+ +When we start the Tk process in the background with (start-wish), we
+can create widgets and place them on the grid interactively.
See the documentation.
+ +Once we’re done, we can (exit-wish).
Nodgui
+ +To try the Nodgui demo, do:
+ +(ql:quickload :nodgui)
+(nodgui.demo:demo)
+Next, we’ll have a look at a very different beast, Qt4, with Qtools.
+ +
+
+
+
+ Camino a la panificación: pan de pandemia
+Onda Hostil 27 03 2020
+
+ 
+
+
+ Acquisition
+MonkeyUser 24 03 2020
+
+
+ Literate Programming in Lisp With Erudite
+Lisp journey 21 03 2020
+Erudite is a Common Lisp library to write literate programs. +The latest release (march, 2020) brings cool new features, amongst which the +ability to capture and print code output.
+ +This page was created with Erudite. You can follow along with its +source here. Blogging about a programming language in the language itself is +pretty awesome and convenient (no more copy-pasting of code snippets +and manual adjustements of the indentation, yay!). It brings us closer +to an interactive notebook, even if it isn’t the first goal.
+ +Basic usage
+ +You write a lisp program, as usual. There is no extra step to produce the program sources, +since we are inside the sources. This is different than the Org-mode approach for example.
+ +The comments will be the documentation. Comments inside a function are +also extracted and cut the function in two.
+ +Erudite can export to Latex, RestructuredText, Markdown, HTML… and +actually to and from any format by using a “pass-through” directive.
+ +
+Top level comments are shown like this. Here’s code:
(defun fibonacci (n &aux (f0 0) (f1 1))
+ "docstring"
+ (case n
+ (0 f0)
+ (1 f1)
+this is an inline comment (there might be settings to control how it is rendered)
+ + (t (loop for n from 2 to n
+ for a = f0 then b and b = f1 then result
+ for result = (+ a b)
+ finally (return result)))))
+
+Erudite defines directives to play with the output, such as ignore and eval. Note that directives start with a @ sign, which I cannot use here.
With ignore, we can write lisp code but hide it from the output. And with eval, Erudite connects to a Swank server, captures and prints the output.
There’s also the handy code, to write a snippet inside comments (so it is not part of
+the Lisp source) and make it appear in the generated document.
For the text markup, we can use Erudite’s +syntax (“link”, “section”, “subsection”, “emph”…), or the markup of +the output file format.
+ +Evaluating code
+ +With the latest Erudite, we can evaluate code. Note that it’s a work +in progress.
+ +The code snippet must be inside the comments too.
+ +Here I call Fibonacci defined above: Fibonacci of 10 is…
+
+55
+
You might need to create a Swank server first with
+ +
+(swank:create-server :dont-close t)
+and tell Erudite its port if it isn’t 4005.
+ +
+(setf erudite::*swank-port* 4005)
+Rendering the document
+ +Call Erudite like so:
+ +
+(erudite:erudite #p"literal.md" "literal-erudite.lisp" :output-type :markdown)
+
+We can also use a binary from the shell.
+ +Live rendering
+ +I don’t want to re-run this command everytime I want to see the generated document. +I use this snippet to automatically export my document when I save the Lisp source:
+ +
+(ql:quickload :cl-inotify)
+
+(bt:make-thread
+ (lambda ()
+ (cl-inotify:with-inotify (inotify t ("literal-erudite.lisp" :close-write))
+ (cl-inotify:do-events (event inotify :blocking-p t)
+ (format t "~a~&" event)
+ (erudite:erudite #p"literal.md" "literal-erudite.lisp" :output-type :markdown))))
+ :name "inotify-erudite")
+
+And then I make the markdown file to be live-rendered in the browser.
+I used impatient-mode for Emacs (see Wikemacs) with the help of M-x auto-revert-mode.
Kuddos to Mariano Montone!
+ +
+
+
+
+ El papel de internet en estos tiempos de crisis
+República Web 20 03 2020
+Queremos dedicar este episodio a todas las personas que están enfrentándose a esta emergencia en primera línea. Son tiempos complicados que exigen unión y sólo nuestra determinación por hacer las cosas juntos nos hará superar esta situación. Mucho ánimo para todos.
+En este episodio hablamos sobre cómo internet está ayudando a sobrellevar esta crisis global y también la forma en la que el acceso a la red supone un alivio en la parte personal y profesional. El avance espectacular del virus ha obligado a aplicar restricciones sin precedentes y en este escenario de aislamiento social, internet está jugando un papel fundamental. Aspectos tan cotidianos como trabajar, estudiar o dedicar tiempo al ocio están siendo posibles gracias a nuestras conexiones a la red.
+Entre las cuestiones que discutimos en el episodio:
+-
+
- Cómo estamos llevando estos días en la parte profesional. +
- Servicios que estamos usando más en la parte de trabajo en remoto. +
- Lo que nos sugiere que en muchos guiones apocalípticos se apuntaba a un fallo de la tecnología o de internet, como el fin de una era.¿No debería ser un derecho el acceso?. +
- Gestos de solidaridad por parte de muchas empresas que ponen a su disposición sus productos digitales. +
- ¿Supone esta crisis un cambio cultural definitivo con respecto al trabajo en remoto?. +
- Cómo pensamos que esta crisis va a afectar a nuestro trabajo. +
¿Algún caso que os gustaría reseñar?
+Por últimos dos grandes oyentes del podcast Cristóbal y Carlos nos han mandado su opinión acerca de las cuestiones hemos tratado en el episodio. Como siempre encantados de contar con vuestras aportaciones al podcast.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ Levels Of Satisfaction
+MonkeyUser 17 03 2020
+
+
+
+
+ Radar Extendido con herramientas, artículos y recursos de desarrollo web
+República Web 13 03 2020
+Tras varias entrevistas y episodios temáticos aprovechamos este episodio del podcast para hacer un radar extendido con recursos y herramientas de interés para el desarrollo web. Recopilamos algunos de los recursos que teníamos apuntados para aportar entre los tres, una lista extendida de nuestra frecuente sección Radar. Cada uno de nosotros se ha preparado unos cuantos enlaces para discutir en este episodio.
+Es inevitable que en este episodio hagamos mención de la crisis del Coronavirus, y hablamos sobre como estamos afrontando los próximos días tanto a nivel personal como profesional. Esta crisis está poniendo a prueba gran parte de los aspectos más esenciales de nuestra vida y casi nadie se escapará de sus efectos en el ámbito profesional.
+Recursos web discutidos en el episodio
+Alpine.js: A Tiny JavaScript Framework (Caleb Porzio)
+Diminuta librería para generar interacciones de usuario listas para usar, sin necesidad de otras opciones más completas. Artículo de Alpine.js en Smashing Magazine.
TailwindUI: Completa colección de snippets de HTML listos para integrar en tu proyecto hecho con TailwindCSS.
+Libro Comerciantes de Atención por Tim Wu, publicado en español por Capitán Swing, un ensayo fundamental para comprender como las empresas de comunicación y publicidad comercian con nuestra atención. Tim Wu es profesor de la Universidad de Columbia y columnista habitual del New York Times.
+Podcast Tribucasters de Pol Rodríguez y José Carlos Cortizo, un podcast para podcasters con un enfoque especial en todo lo relacionado con producir y captar audiencia en el mundo del podcast.
+Place Image, una aplicación de Andros para facilitar una colección de imágenes aleatorias y en diferentes tamaños, destinado a facilitar el trabajo del desarrollo y diseño web.
+LocalWP por Flywheel, ofrece un entorno de trabajo local con soporte SSL, dominios locales, Mailhog, instalación en un clic, refresco automático, wp cli, acceso SSH, últimas versiones de MySQL y PHP, configurar entorno de desarrollo o producción, extensiones….
+Retool, una aplicación que promete recortar el tiempo que lleva construir herramientas internas.
+Libro Algoritmos, Guía ilustrada para programadores y curiosos por Aditya Y. Bhargava. Una guía muy bien ilustrada que enseña cómo aplicar algoritmos comunes a problemas prácticos que enfrentan a diario los programadores.
+Podcast de formación por David Vaquero y José Jiménez, Formadores en tiempos revueltos iVoox, Anchor.fm.
+anchor.fm https://anchor.fm/s/13cc5df4/podcast/rss
Gadgets para freelance itinerantes o nómadas digitales
+ + +Artículo de David Vaquero sobre Angular 9 nueva release
+Artículo de David Vaquero sobre Ionic 5 nueva release
+Muchísimas gracias a nuestra querida Sonia Sánchez por hacernos la presentación de este episodio.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ Fusión Reactiva, compartiendo experiencias profesionales junto a Daniel Primo
+República Web 10 03 2020
+Para este episodio especial compartimos micrófono con nuestro colega podcaster Daniel Primo de Web Reactiva. Aunque alguno ya hemos compartido con Daniel micrófono tanto en su podcast, como en el nuestro, es la primera vez que podemos hablar los cuatro juntos en un episodio. Con Dani aprovechamos para compartir nuestras experiencias profesionales, hablando de cuestiones aprendidas con los años, alguno de nuestros logros recientes y la percepción que tenemos de nuestra profesión.
+Se trata de un episodio que publicará Dani en su programa Web Reactiva y que nosotros hemos decidido publicar como bonus en nuestro feed oficial. En este episodio también hay espacio para hablar sobre proyectos de futuro y lo que tenemos cada uno entre manos. Un episodio en modo tertulia entre amigos y colegas, y que pensamos puede resultar de interés a nuestros respectivos oyentes.
+Entre las cuestiones que tratamos en el episodio se encuentran:
+-
+
- ¿Qué es lo mejor que habéis hecho a nivel profesional los últimos 2 ó 3 años? +
- ¿De qué tecnología, hábito o disciplina profesional estás más orgulloso? +
- ¿De qué forma ha cambiado vuestra percepción de la profesión con los años? +
- Un buen consejo que os hayan dado a nivel profesional y que se haya demostrado efectivo. +
- Objetivos y proyectos de futuro. +
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ Early Contributor
+MonkeyUser 10 03 2020
+
+
+ Generate an SEO-Friendly Sitemap for your Gatsby Site
+Josh Comeau's blog 09 03 2020
+
+
+
+
+ Infraestructura para proyectos web con Iván Expósito de Dinahosting
+República Web 06 03 2020
+Para este episodio David Vaquero habla con Iván Expósito de Dinahosting, uno de los proveedores de infraestructura de alojamiento, dominios y servicios web más importantes de España. David aprovecha que es cliente de larga trayectoria de Dinahosting para conversar sobre los servicios que ofrecen, sus puntos de diferenciales y los nuevos proyectos que tienen para el futuro.
+Dinahosting ofrece desde el año 2001 un catálogo amplísimo de servicios que van desde el registro de dominios, el hosting web y servidores VPS / dedicados. Con sedes en Santiago de Compostela y Madrid (datacenter), Dinahosting ofrece todo lo necesario para lanzar proyectos web y garantizar su crecimiento, desde alojamientos compartidos y soluciones más avanzadas. Con Iván Expósito hablamos de la personalidad de Dinahosting y su cultura de atención al cliente.
+También hay espacio para hablar de proyectos paralelos dentro de la empresa, migraciones a VPS, código abierto, cloud privadas y requerimientos para lanzar proyectos y soporte personalizado a clientes. Dinahosting es una solución perfecta para poder crecer proyectos web con todo lo necesario para garantizar el acceso a nuestros servicios, sin contar con un personal técnico en las empresas.
+Por último también hablamos de DinaIP, una solución desarrollada por Dinahosting para configurar direcciones dinámicas.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Writing a bytecode interpreter - in C
+Danny van Kooten 05 03 2020
+Some time during 2016 I got my hands on the book Writing an interpreter in Go by Thorsten Ball. I skimmed through the first few chapters, liked what I read and then… life happened and I never actually got around to building an interpreter. :(
+ +Until last month, that is. I cleared out my schedule and finally started going through the book.
+ +For double the fun, I picked C as my programming language of choice instead of Go. This turned out to be a great decision as it really forced me to understand what was going on, instead of always having the easy option of just copying the author’s code.
+ +I codenamed my implementation Monkey-C Monkey-Do.
+ +The book takes you through all the stages to get an interpreter for the Monkey programming language up and running:
+ +-
+
- Tokenize the input +
- Parse the tokens into an Abstract Syntax Tree (AST) +
- Evaluate the tree +
This tree-walking evaluator needs about 6 seconds to calculate the 35th fibonacci number using a very sub-optimal algorithm with lots of recursion. That is certainly not bad, but it’s also not great compared to any of today’s production-grade interpreted languages.
+ +For comparison, on the same machine Python 3.7 needs 2.3 seconds for that exact same algorithm and Node 15 only needs a whopping 200 miliseconds (due to its JIT compilation).
+ +Can we do better, without talking to the hardware directly?
+ +Writing a bytecode compiler and virtual machine
+ +Luckily, the author of the book didn’t stop there. In his second book (Writing a compiler in Go) the author walks you through the steps of building a bytecode interpreter.
+ +Reusing the AST from the first book, it shows you how to build a compiler outputting bytecode. Simultaneously, you start building a virtual machine capable of executing that bytecode.
+ +After getting the virtual machine up and running, calculating the 35th fibonacci number now only takes 0.82 seconds. That’s much closer or even faster than some other interpreted languages already.
+ +I wholeheartedly recommend the two books. Not only is it a lot of fun to write your own interpreter, it also cleared up a lot of the magic for me surrounding how interpreters actually work and what happens behind the scene when a program is evaluated by an interpreter.
+ +Programming in C
+ +This was my first experience programming in C and it surprised me to discover that I really enjoyed using it. Because of the small language specification very little time was spent reading documentation.
+ +That’s not to say I did not shoot myself in the foot a good few times or struggled with memory management. Using C really cemented my understanding of some of the languages that came after it though. And what problems they attempt to solve or improve upon over C.
+ +Given the right tooling, I’ve grown quite fond of C… Sorry, not sorry.
+ +Resources
+ +-
+
- Book: The C Programming Language by Kernighan & Ritchie. Still the best resource for learning C. +
- Tools: Valgrind, Gprof, GNU make, GNU Debugger +
- This comment in the CPython source explaining the use of computed GOTO’s in the VM for a performance gain due to better CPU branch prediction over using a switch statement. +
- Memory allocation strategies by Ginger Bill. +
+
+ February 2020 Update
+News on Clojurists Together 04 03 2020
+
+ 
+
+
+ Common Lisp Macros By Example Tutorial
+Lisp journey 02 03 2020
+I have recently edited and somewhat expanded the macros page on the +Common Lisp Cookbook. I find it may more legible and reader friendly, +so I reproduce it below (however, I cut two parts so than you get the essential).
+ +You’d better read it on the Cookbook: https://lispcookbook.github.io/cl-cookbook/macros.html
+ ++ +
The word macro is used generally in computer science to mean a syntactic extension to a programming language. (Note: The name comes from the word “macro-instruction,” which was a useful feature of many second-generation assembly languages. A macro-instruction looked like a single instruction, but expanded into a sequence of actual instructions. The basic idea has since been used many times, notably in the C preprocessor. The name “macro” is perhaps not ideal, since it connotes nothing relevant to what it names, but we’re stuck with it.) Although many languages have a macro facility, none of them are as powerful as Lisp’s. The basic mechanism of Lisp macros is simple, but has subtle complexities, so learning your way around it takes a bit of practice.
+ +How Macros Work
+ +A macro is an ordinary piece of Lisp code that operates on another piece of putative Lisp code, translating it into (a version closer to) executable Lisp. That may sound a bit complicated, so let’s give a simple example. Suppose you want a version of setq that sets two variables to the same value. So if you write
(setq2 x y (+ z 3))
+when z=8 then both x and y are set to 11. (I can’t think of any use for this, but it’s just an example.)
It should be obvious that we can’t define setq2 as a function. If x=50 and y=-5, this function would receive the values 50, -5, and 11; it would have no knowledge of what variables were supposed to be set. What we really want to say is, When you (the Lisp system) see:
(setq2 v1 v2 e)
+then treat it as equivalent to:
+ +(progn
+ (setq v1 e)
+ (setq v2 e))
+Actually, this isn’t quite right, but it will do for now. A macro allows us to do precisely this, by specifying a program for transforming the input pattern (setq2 v1 v2 e) into the output pattern (progn ...).
Quote
+ +Here’s how we could define the setq2 macro:
(defmacro setq2 (v1 v2 e)
+ (list 'progn (list 'setq v1 e) (list 'setq v2 e)))
+It takes as parameters two variables and one expression.
+ +Then it returns a piece of code. In Lisp, because code is represented +as lists, we can simply return a list that represents code.
+ +We also use the quote: each quoted symbol evaluates to itself, aka +it is returned as is:
+ +-
+
(quote foo bar baz)returns(foo bar baz)
+- the quote character,
', is a shortcut forquote, a special operator (not a function nor a macro, but one of a few special operators forming the core of Lisp).
+ - so,
'fooevaluates tofoo.
+
So, our macro retourns the following bits:
+ +-
+
- the symbol
progn,
+ - a second list, that contains
+
+
-
+
- the symbol
setq
+ - the variable
v1: note that the variable is not evaluated inside the macro!
+ - the expression
e: it is not evaluated either!
+
+ - the symbol
- a second list, with
v2.
+
We can use it like this:
+ +(defparameter v1 1)
+(defparameter v2 2)
+(setq2 v1 v2 3)
+;; 3
+We can check, v1 and v2 were set to 3.
Macroexpand
+ +We must start writing a macro when we know what code we want to
+generate. Once we’ve begun writing one, it becomes very useful to
+check effectively what code does the macro generate. The function for
+that is macroexpand. It is a function, and we give it some code, as
+a list (so, we quote the code snippet we give it):
(macroexpand '(setq2 v1 v2 3))
+;; (PROGN (SETQ V1 3) (SETQ V2 3))
+;; T
+Yay, our macro expands to the code we wanted!
+ +More interestingly:
+ +(macroexpand '(setq2 v1 v2 (+ z 3)))
+;; (PROGN (SETQ V1 (+ z 3)) (SETQ V2 (+ z 3)))
+;; T
+We can confirm that our expression e, here (+ z 3), was not
+evaluated. We will see how to control the evaluation of arguments with
+the comma: ,.
Note: with Slime, you can call macroexpand by putting the cursor at
+the left of the parenthesis of the s-expr to expand and call the functionM-x
+slime-macroexpand-[1,all], or C-c M-m:
[|](setq2 v1 v2 3)
+;^ cursor
+; C-c M-m
+; =>
+; (PROGN (SETQ V1 3) (SETQ V2 3))
+Macros VS functions
+ +Our macro is very close to the following function definition:
+ +(defun setq2-function (v1 v2 e)
+ (list 'progn (list 'setq v1 e) (list 'setq v2 e)))
+If we evaluated (setq2-function 'x 'y '(+ z 3)) (note that each
+argument is quoted, so it isn’t evaluated when we call the
+function), we would get
(progn (setq x (+ z 3)) (setq y (+ z 3)))
+This is a perfectly ordinary Lisp computation, whose sole point of interest is that its output is a piece of executable Lisp code. What defmacro does is create this function implicitly and make sure that whenever an expression of the form (setq2 x y (+ z 3)) is seen, setq2-function is called with the pieces of the form as arguments, namely x, y, and (+ z 3). The resulting piece of code then replaces the call to setq2, and execution resumes as if the new piece of code had occurred in the first place. The macro form is said to expand into the new piece of code.
Evaluation context
+ +This is all there is to it, except, of course, for the myriad subtle consequences. The main consequence is that run time for the setq2 macro is compile time for its context. That is, suppose the Lisp system is compiling a function, and midway through it finds the expression (setq2 x y (+ z 3)). The job of the compiler is, of course, to translate source code into something executable, such as machine language or perhaps byte code. Hence it doesn’t execute the source code, but operates on it in various mysterious ways. However, once the compiler sees the setq2 expression, it must suddenly switch to executing the body of the setq2 macro. As I said, this is an ordinary piece of Lisp code, which can in principle do anything any other piece of Lisp code can do. That means that when the compiler is running, the entire Lisp (run-time) system must be present.
We’ll stress this once more: at compile-time, you have the full language at your disposal.
+ +Novices often make the following sort of mistake. Suppose that the setq2 macro needs to do some complex transformation on its e argument before plugging it into the result. Suppose this transformation can be written as a Lisp procedure some-computation. The novice will often write:
(defmacro setq2 (v1 v2 e)
+ (let ((e1 (some-computation e)))
+ (list 'progn (list 'setq v1 e1) (list 'setq v2 e1))))
+
+(defmacro some-computation (exp) ...) ;; _Wrong!_
+The mistake is to suppose that once a macro is called, the Lisp system enters a “macro world,” so naturally everything in that world must be defined using defmacro. This is the wrong picture. The right picture is that defmacro enables a step into the ordinary Lisp world, but in which the principal object of manipulation is Lisp code. Once that step is taken, one uses ordinary Lisp function definitions:
(defmacro setq2 (v1 v2 e)
+ (let ((e1 (some-computation e)))
+ (list 'progn (list 'setq v1 e1) (list 'setq v2 e1))))
+
+(defun some-computation (exp) ...) ;; _Right!_
+One possible explanation for this mistake may be that in other languages, such as C, invoking a preprocessor macro does get you into a different world; you can’t run an arbitrary C program. It might be worth pausing to think about what it might mean to be able to.
+ +Another subtle consequence is that we must spell out how the arguments to the macro get distributed to the hypothetical behind-the-scenes function (called setq2-function in my example). In most cases, it is easy to do so: In defining a macro, we use all the usual lambda-list syntax, such as &optional, &rest, &key, but what gets bound to the formal parameters are pieces of the macro form, not their values (which are mostly unknown, this being compile time for the macro form). So if we defined a macro thus:
(defmacro foo (x &optional y &key (cxt 'null)) ...)
+then
+ +| If we call it thus … | +The parameters’ values are … | +
|---|---|
(foo a) |
+x=a, y=nil, cxt=null |
+
(foo (+ a 1) (- y 1)) |
+x=(+ a 1), y=(- y 1), cxt=null |
+
(foo a b :cxt (zap zip)) |
+x=a, y=b, cxt=(zap zip) |
+
Note that the values of the variables are the actual expressions (+ a 1) and (zap zip). There is no requirement that these expressions’ values be known, or even that they have values. The macro can do anything it likes with them. For instance, here’s an even more useless variant of setq: (setq-reversible e1 e2 d) behaves like (setq e1 e2) if d=:normal, and behaves like (setq e2 e1) if d=:backward. It could be defined thus:
(defmacro setq-reversible (e1 e2 direction)
+ (case direction
+ (:normal (list 'setq e1 e2))
+ (:backward (list 'setq e2 e1))
+ (t (error "Unknown direction: ~a" direction))))
+Here’s how it expands:
+ +(macroexpand '(setq-reversible x y :normal))
+(SETQ X Y)
+T
+(macroexpand '(setq-reversible x y :backward))
+(SETQ Y X)
+T
+And with a wrong direction:
+ +(macroexpand '(setq-reversible x y :other-way-around))
+We get an error and are prompted into the debugger!
+ +We’ll see the backquote and comma mechanism in the next section, but +here’s a fix:
+ +(defmacro setq-reversible (v1 v2 direction)
+ (case direction
+ (:normal (list 'setq v1 v2))
+ (:backward (list 'setq v2 v1))
+ (t `(error "Unknown direction: ~a" ,direction))))
+ ;; ^^ backquote ^^ comma: get the value inside the backquote.
+
+(macroexpand '(SETQ-REVERSIBLE v1 v2 :other-way-around))
+;; (ERROR "Unknown direction: ~a" :OTHER-WAY-AROUND)
+;; T
+Now when we call (setq-reversible v1 v2 :other-way-around) we still get the
+error and the debugger, but at least not when using macroexpand.
Backquote and comma
+ +Before taking another step, we need to introduce a piece of Lisp notation that is indispensable to defining macros, even though technically it is quite independent of macros. This is the backquote facility. As we saw above, the main job of a macro, when all is said and done, is to define a piece of Lisp code, and that means evaluating expressions such as (list 'prog (list 'setq ...) ...). As these expressions grow in complexity, it becomes hard to read them and write them. What we find ourselves wanting is a notation that provides the skeleton of an expression, with some of the pieces filled in with new expressions. That’s what backquote provides. Instead of the the list expression given above, one writes
`(progn (setq ,v1 ,e) (setq ,v2 ,e))
+;;^ backquote ^ ^ ^ ^ commas
+The backquote (`) character signals that in the expression that follows, every subexpression not preceded by a comma is to be quoted, and every subexpression preceded by a comma is to be evaluated.
+ +You can think of it, and use it, as data interpolation:
+ +`(v1 = ,v1) ;; => (V1 = 3)
+That’s mostly all there is to backquote. There are just two extra items to point out.
+ +Comma-splice ,@
+ +First, if you write “,@e” instead of “,e” then the value of e is spliced (or “joined”, “combined”, “interleaved”) into the result. So if v equals (oh boy), then
(zap ,@v ,v)
+evaluates to
+ +(zap oh boy (oh boy))
+;; ^^^^^ elements of v (two elements), spliced.
+;; ^^ v itself (a list)
+The second occurrence of v is replaced by its value. The first is replaced by the elements of its value. If v had had value (), it would have disappeared entirely: the value of (zap ,@v ,v) would have been (zap ()), which is the same as (zap nil).
Quote-comma ‘,
+ +When we are inside a backquote context and we want to print an +expression literally, we have no choice but to use the combination of +quote and comma:
+ +(defmacro explain-exp (exp)
+ `(format t "~S = ~S" ',exp ,exp))
+ ;; ^^
+
+(explain-exp (+ 2 3))
+;; (+ 2 3) = 5
+See by yourself:
+ +;; Defmacro with no quote at all:
+(defmacro explain-exp (exp)
+ (format t "~a = ~a" exp exp))
+(explain-exp v1)
+;; V1 = V1
+
+;; OK, with a backquote and a comma to get the value of exp:
+(defmacro explain-exp (exp)
+ ;; WRONG example
+ `(format t "~a = ~a" exp ,exp))
+(explain-exp v1)
+;; => error: The variable EXP is unbound.
+
+;; We then must use quote-comma:
+(defmacro explain-exp (exp)
+ `(format t "~a = ~a" ',exp ,exp))
+(explain-exp (+ 1 2))
+;; (+ 1 2) = 3
+Nested backquotes
+ +Second, one might wonder what happens if a backquote expression occurs inside another backquote. The answer is that the backquote becomes essentially unreadable and unwriteable; using nested backquote is usually a tedious debugging exercise. The reason, in my not-so-humble opinion, is that backquote is defined wrong. A comma pairs up with the innermost backquote when the default should be that it pairs up with the outermost. But this is not the place for a rant; consult your favorite Lisp reference for the exact behavior of nested backquote plus some examples.
+ +Building lists with backquote
+ +[…]
+ +Getting Macros Right
+ +I said in the first section that my definition of setq2 wasn’t quite right, and now it’s time to fix it.
Suppose we write (setq2 x y (+ x 2)), when x=8. Then according to the definition given above, this form will expand into
(progn
+ (setq x (+ x 2))
+ (setq y (+ x 2)))
+so that x will have value 10 and y will have value 12. Indeed, here’s its macroexpansion:
(macroexpand '(setq2 x y (+ x 2)))
+;;(PROGN (SETQ X (+ X 2)) (SETQ Y (+ X 2)))
+Chances are that isn’t what the macro is expected to do (although you never know). Another problematic case is (setq2 x y (pop l)), which causes l to be popped twice; again, probably not right.
The solution is to evaluate the expression e just once, save it in a temporary variable, and then set v1 and v2 to it.
Gensym
+ +To make temporary variables, we use the gensym function, which returns a fresh variable guaranteed to appear nowhere else. Here is what the macro should look like:
(defmacro setq2 (v1 v2 e)
+ (let ((tempvar (gensym)))
+ `(let ((,tempvar ,e))
+ (progn (setq ,v1 ,tempvar)
+ (setq ,v2 ,tempvar)))))
+Now (setq2 x y (+ x 2)) expands to
(let ((#:g2003 (+ x 2)))
+ (progn (setq x #:g2003) (setq y #:g2003)))
+Here gensym has returned the symbol #:g2003, which prints in this funny way because it won’t be recognized by the reader. (Nor is there any need for the reader to recognize it, since it exists only long enough for the code that contains it to be compiled.)
Exercise: Verify that this new version works correctly for the case (setq2 x y (pop l1)).
Exercise: Try writing the new version of the macro without using backquote. If you can’t do it, you have done the exercise correctly, and learned what backquote is for!
+ +The moral of this section is to think carefully about which expressions in a macro get evaluated and when. Be on the lookout for situations where the same expression gets plugged into the output twice (as e was in my original macro design). For complex macros, watch out for cases where the order that expressions are evaluated differs from the order in which they are written. This is sure to trip up some user of the macro - even if you are the only user.
What Macros are For
+ +[…]
+ +See also
+ +A gentle introduction to Compile-Time Computing — Part 1
+ + + +The following video, from the series +“Little bits of Lisp” +by cbaggers, is a two hours long talk +on macros, showing simple to advanced concepts such as compiler +macros: +https://www.youtube.com/watch?v=ygKXeLKhiTI +It also shows how to manipulate macros (and their expansion) in Emacs.
+ +
+
+ Yes Google Uses and Hacks on Common Lisp
+Lisp journey 02 03 2020
+ITA Software, owned by +Google, the airfare search and pricing system that is still used by +companies such as Kayak.com or Orbitz, is a well-known example of a +successful industrial and large Common Lisp software.
+ +We’re legitimate to wonder if they still run it (they do), if Google +develops more CL software (I don’t know), or if they put resources to +improve a CL implementation: they do.
+ +According to https://mstmetent.blogspot.com/2020/01/sbcl20-in-vienna-last-month-i-attended.html:
+ +++ +Doug Katzman talked about his work at Google getting SBCL to work with Unix better. For those of you who don’t know, he’s done a lot of work on SBCL over the past couple of years, not only adding a lot of new features to the GC and making it play better with applications which have alien parts to them, but also has done a tremendous amount of cleanup on the internals and has helped SBCL become even more Sanely Bootstrappable. That’s a topic for another time, and I hope Doug or Christophe will have the time to write up about the recent improvements to the process, since it really is quite interesting.
+ +Anyway, what Doug talked about was his work on making SBCL more amenable to external debugging tools, such as gdb and external profilers. It seems like they interface with aliens a lot from Lisp at Google, so it’s nice to have backtraces from alien tools understand Lisp. It turns out a lot of prerequisite work was needed to make SBCL play nice like this, including implementing a non-moving GC runtime, so that Lisp objects and especially Lisp code (which are normally dynamic space objects and move around just like everything else) can’t evade the aliens and will always have known locations.
+
So now that’s in the wild, Common Lisp can go trendy again: Google uses and dedicates resources for Common Lisp!
+ +
+ 
+
+
+ Accesibilidad y web inclusiva con Javier Hernández y Vicent Sanchis
+República Web 29 02 2020
+Nos acompañan para este episodio Javier Hernández y Vicent Sanchis, dos profesionales del mundo web y especialistas en accesibilidad y web inclusiva. Aunque sobre el papel muchos profesionales simpatizan, son pocos los que le prestan una atención especial y tiempo. En su origen uno de los objetivos de la web era conseguir un acceso universal a la información por cualquier persona, sin que sus dificultades físicas o cognitivas se lo impidan. No obstante, por desconocimiento o falta de empatía, la accesibilidad pasa por ser un asunto menor, al que ni siquiera muchos proyectos dedican atención.
+
La experiencia de Javier Hernández en Estudio Inclusivo
+Javier es socio fundador de Estudio Inclusivo, un singular estudio de diseño web especializado en accesibilidad web. Su equipo cuenta con personas con diversas discapacidades y ha desarrollado multitud de proyectos web, con la accesibilidad como objetivo fundamental. El equipo de Estudio Inclusivo también ha desarrollado un plugin para WordPress que ayuda a implantar soluciones de accesibilidad en los sitios web. En esta entrevista Javier nos habla de su experiencia, de la actualidad del mundo de la accesibilidad y su visión acerca de cómo llevarla a cabo.
+Vicent Sanchis, un especialista en visión y desarrollo accesible
+Vicent Sanchis es especialista en visión y Doctorado en Ciencias de la Visión. Además combina su actividad profesional como desarrollador web y técnico en accesibilidad. Vicent es un ponente habitual en los meetups de WordPress, donde suele ofrecer información de interés sobre accesibilidad. Vicent nos cuenta unos detalles de gran interés y que nos ayudan a entender mejor las necesidades de las personas con dificultades de acceso a los contenidos.
+Entre las cuestiones que discutimos con ellos:
+-
+
- ¿Qué porcentaje de usuarios de internet se calcula que pueden tener necesidades especiales de accesibilidad y qué tipo de dificultades existen para acceder a la información? ¿Qué tipos de minusvalías afectan a la navegación? +
- ¿Cuál es la mejor forma de afrontar un proyecto web accesible?. +
- ¿Cómo está actualmente la legislación en materia de accesibilidad web y qué se le puede exigir al propietario de un sitio web?. +
- ¿Qué buenas prácticas le recomendarías a un desarrollador web para tener un sitio web mínimamente accesible? +
Agradecimiento a nuestra amiga Iga Kurowska por grabarnos la intro del episodio y darle un toque más femenino a este programa.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ En que ando: febrero
+Onda Hostil 29 02 2020
+
+
+ Clojure Homebrew Tap
+Clojure News 28 02 2020
+
+
+
+
+
+
+For Mac or Linux users using Homebrew, Clojure now has its own Homebrew tap, clojure/tools. Creating an official Clojure tap has the following advantages:
+
+-
+
-
+
Clojure team controls formula contents
+
+ -
+
Clojure team controls release timing
+
+ -
+
Freedom to keep an archive of older versioned releases that would be too much for the core tap
+
+ -
+
Easier to automate releases
+
+
+
+Dependencies
+
+
+
+
+Clojure requires Java. Clojure officially supports Java LTS releases (currently Java 8 and Java 11), but also tries to ensure interim versions work as well. You can use any Java installation, whether it’s a commercial release from Oracle or an open source version based on OpenJDK (like adoptopenjdk).
+
+
+The Clojure tools require that either the java command is on the path or that the JAVA_HOME environment variable is set.
+
+How do I use it?
+
+
+
+
+Using an external homebrew tap just requires combining the tap location and the formula name:
+
+
+
+
+brew install clojure/tools/clojure
+
+for a new install or:
+
+
+
+
+brew upgrade clojure/tools/clojure
+
+to upgrade your current install. For more detailed information, see the docs at the tap. Other pages on the Clojure site have been updated appropriately.
+
+
+Development, stable, and archived releases
+
+
+
+
+As those docs describe, there are now three flavors of release available:
+
+
+-
+
-
+
Stable releases (obtained with the commands above) - this is what most people should use and we expect to update these on the frequency of every 1-3 months.
+
+ -
+
Development releases (using the --devel flag) - the latest bits, probably best for tools developers and those evaluating new bug fixes or functionality. New development releases may come out as frequently as multiple times per week during active periods.
+
+ -
+
Archived version releases - occasionally, it may be useful to install a specific older release, and there will now be an archive of these release formulas available. See the tap docs for how to use.
+
+
+
+
+ What about the core tap?
+
+
+
+
+The Homebrew core tap still has a clojure formula for the Clojure tools. You should now consider that unofficial and likely to lag behind the Clojure tap, which should be preferred. Anyone can update it, or we may periodically bump it for big releases, but we will not be actively updating it as of now.
+
+ 
+
+
+ Planned vs Budgeted
+MonkeyUser 25 02 2020
+
+
+ Persisting React State in localStorage
+Josh Comeau's blog 24 02 2020
+
+
+
+
+ Lo que he aprendido: pdfjam y la ANECA
+Onda Hostil 24 02 2020
+
+ 
+
+
+ Seguridad en WordPress con Néstor Angulo de Ugarte
+República Web 22 02 2020
+Seguimos con la racha de invitados en el podcast y esta semana contamos con Néstor Angulo de Ugarte, especialista en seguridad web de la empresa Sucuri, integrada ahora en la compañía GoDaddy. Néstor trabaja en remoto para Sucuri investigando casos de hackeo en entornos web y dando respuesta a los problemas de seguridad de los clientes.
+
Como nuestro último invitado, Guillermo, Néstor también estuvo en la WordCamp con Andros como ponente donde ofreció una charla sobre seguridad en WordPress. Con Néstor queremos hablar precisamente de esto de seguridad WordPress, o más específicamente de la forma en la que se puede comprometer una instalación de WordPress y las cuestiones a tener en cuenta para ofrecer más seguridad. Además tenemos la suerte de haber contado con él para grabar en las instalaciones de Idecrea y eso ha hecho si cabe más amena la entrevista.
+Entre las cuestiones que hablamos con Néstor:
+-
+
- Motivaciones más habituales de un atacante a un sitio web con WordPress. +
- Los ataques más comunes en sitios web con WordPress. +
- Medidas básicas para proteger nuestro WordPress. +
- Limpiar correctamente un WordPress infectado. +
- Soporte y mantenimiento de sitios web. +
- Fuentes y medios de información para estar al día. +
- Certificados y auditorias de seguridad para plugins y temas. +
Descuentos para licencias de JetBrains.
+David Vaquero ofrece una clave para aprovecharse del 20% de descuento en licencias de productos de JetBrains. Es válido hasta 10 licencias de uso, con lo que los primeros que compren, son las que se lo llevan.
+Código: MGLGX-9Y9J9-LX3XZ-YCQU6-UTYED
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ Cómo cohabitan la vida salvaje y el ser humano en el lugar más frío de Grecia
+Sección Materia | Ciencia en EL PAÍS 21 02 2020
+
+
+
+
+ “Bueno, ya no piso ningún bicho”
+Sección Materia | Ciencia en EL PAÍS 21 02 2020
+
+
+ Setting up Syncthing to synchronise files between computers
+Posts on James Routley 21 02 2020
+
+ 
+
+
+ State of Clojure 2020 Results
+Clojure News 20 02 2020
+
+
+
+
+
+
+Ten years ago, Chas Emerick ran the first State of Clojure survey. In 2010, most users had been using Clojure for just weeks or months, and few were using it as a language for serious work. This year, we see consistent and growing use for work, steady interest in the key value propositions of Clojure, and an ever-evolving community of users.
+
+
+Clojure at Work
+
+
+
+
+One of the questions we have been asking since 2010 is whether respondents are using Clojure for work, hobby projects, tinkering, or studies. This year, we saw the highest percentage yet of Clojure use at work:
+
+
+
+
+
+
+
+
+Additionally, we saw a small shift in company size to bigger companies - an increase of 3% in companies of size 1000+ (and reduction in companies size 1-10).
+
+
+
+
+
+
+
+
+We also asked respondents for the first time how many people were using Clojure at their organization. As expected, many Clojure teams are small. As a high-leverage tool, Clojure is a great fit for small highly-productive teams. However, it was also great to see many respondents at companies with 40 or even 100+ Clojure developers.
+
+
+
+
+
+
+
+
+A question we’ve been asking since 2010 (with some variation in wording and choices), is in what domains Clojure is being used. The top results have not changed too much over the years but we did see a noticeable increase this year in "enterprise applications", to its highest level ever.
+
+
+
+
+
+
+
+
+Feedback comments indicate Clojure is a tool yielding high leverage for both companies and teams:
+
+
+-
+
-
+
"Clojure continues to be a force multiplier and a vital enabler for our production system."
+
+ -
+
"Clojure enables our small team to do more with less."
+
+ -
+
"Clojure is by far the best language I have to use at work, and it is a pleasure to solve problems using it. It is almost perfect."
+
+ -
+
"Clojure is powering our data driven insurance ERP. I cannot think of a better approach. Many thanks!"
+
+ -
+
"Hard to find too many complaints about Clojure: it’s a wonderful language with a great community. I plan to stay with this language + community for a long time. We have basically bet the company’s technical strategy on it."
+
+ -
+
"I love using Clojure and ClojureScript and have moved all our development projects using various different languages (PHP, Python, C#, Javascript) to only using Clojure and ClojureScript"
+
+ -
+
"Our startup is built solely on Clojure and Clojurescript and we are very happy with it."
+
+
+
+Clojure’s use continues to grow at hundreds of companies, with an ever higher percentage of developers using it at work for their core business.
+
+
+Values
+
+
+
+
+Since 2015, we have asked a question about which aspects of Clojure users valued the most. The weighted ranking of those answers has remained virtually identical since 2015. The most important things to Clojure users are: functional programming, the REPL, immutable data, ease of development, and host interop. Indeed these are all things intrinsic to the Clojure experience and align strongly with the reasons Clojure exists.
+
+
+The open feedback comments often praised the steady arc of Clojure’s development and tradition for growing without breaking:
+
+
+-
+
-
+
"Clojure is an awesome lisp, lovingly created with taste and refinement. It is a pleasure to think and implement in the abstractions provided."
+
+ -
+
"Great work, team! This is the most stable technology I’ve used in my many years doing software development."
+
+ -
+
"I love what you are doing with the language and community. In the world of churn and constantly pumping changes just to create 'buzz' clojure is like a safe zone where my sanity is kept alive."
+
+ -
+
"I really like the simplicity of Clojure and the functional nature of it. I also like the fact that the team doesn’t slap on a ton of features like every other language out there."
+
+ -
+
"Thanks for sticking to the principles: lean, conservative, essential, no frills, production grade software that brought back Lisp to the mainstream."
+
+
+
+Community
+
+
+
+
+Again this year we surveyed the most popular forums where Clojurists interact with each other. Some new and/or rising entries included in-person Clojure conferences (we saw many new ones this year!), the new Ask Clojure site, Telegram chats, and Discord.
+
+
+
+
+
+
+
+
+We also collect information on how users are involved in the Clojure ecosystem. The response this year were very similar to last year but we did see mild upticks in helping new Clojure users, advocating for Clojure in their organization, and maintaining open source libraries, all great contributions!
+
+
+
+
+
+
+
+
+In feedback comments, many people enjoyed the kind and responsive Clojure community:
+
+
+-
+
-
+
"The Clojure community is absolutely fantastic. Being able to post a question and get thoughtful & insightful answers quickly is immensely valuable. Thank you for fostering such an incredible community."
+
+ -
+
"Clojure (Script) is a great, well-thought out language that has helped me tremendously in my work. However, it also exposed me to a wonderful community of thoughtful developers who have given me wonderful new insights, while remaining a friendly and welcoming community"
+
+ -
+
"Wonderful language and a uniquely insightful community. It has helped me rediscover my love for programming."
+
+
+
+
+
+ Deep Dives
+
+
+
+
+Clojure developers will be particularly interested in the version and tooling related questions in the survey.
+
+
+One new question we asked this year was about the primary developer operating system to give us better guidance about tool-related work. As expected, MacOS was the leader (55%), followed by Linux (35%) and Windows (9%):
+
+
+
+
+
+
+
+
+For primary development tool, there were only minor updates this year. Emacs dropped slightly to 43%, IntelliJ/Cursive rose slightly to 32%, and VS Code with Calva had the biggest increase to 10%.
+
+
+
+
+
+
+
+
+Clojure users have a wealth of fine development environments, each suited to different communities and tastes, and we’re glad to see them all getting better day by day.
+
+
+For many years, the survey has included a question about "build tools", but this idea of a single monolithic tool has become increasingly less reflective of how people are managing Clojure projects, where they may use multiple tools for different parts of their process, particularly in mixed Clojure/ClojureScript projects. In response to this, we tailored this question more tightly to dependency management and made it multi-select this year:
+
+
+
+
+
+
+
+
+Looking at previous years, we continue to see strong (but slightly reduced) use of Leiningen, and a steady increase in use of clj/deps.edn. For ClojureScript work, shadow-cljs has made big strides over the last couple years, with big support from Clojurists Together.
+
+
+In the greater world of Java and the JVM, Java has migrated to a new release strategy where releases come out every spring and fall, and every 3 years there is a "long term support" (LTS) release - 8, 11, and (presumably) 17. Java 9 introduced a major change with the module system and in all JVM communities this has caused a significant user base to remain on Java 8. Clojure reflects this as well (although probably shows more shift to Java 11 than other language communities):
+
+
+
+
+
+
+
+
+Releases like Java 9, 10, 12, and soon 13 are effectively dead when the next release comes out and we would recommend sticking primarily to the LTS releases and maybe the latest release, if it’s not an LTS release.
+
+
+One aspect of Java 11 that is underappreciated is significant work to make Java work better in containers like Docker. If you are deploying in containerized environments with Java 8, you should really be looking closely at the changes in Java 11 and considering an upgrade.
+
+
+Clojure itself has been using Java 8 as the baseline JVM for a couple years and will continue to do so (while also supporting newer versions of Java). When running Clojure, we recommend Java 8 or 11 right now.
+
+
+Since last year, we’ve seen strong uptake of Clojure 1.10.0 and 1.10.1. The latter was a maintenance release this year with error handling improvements building on the changes in Clojure 1.10.0 and mitigations for some Java performance regressions in their service releases after Java 8u201. Use of Clojure 1.8 and earlier continues to dwindle:
+
+
+
+
+
+
+
+
+In addition to the prior dependency management question, we also added a new question on how respondents are starting their apps in production. Based on feedback, it’s likely the wording and answer choices will need some fine-tuning next year, but there is some interesting feedback in the results:
+
+
+
+
+
+
+
+
+The majority of users are using launchers like Leiningen or clj to start their production apps, more so than by building jars or uberjars and launching them directly with Java. We do see a small group also experimenting with Graal native images (particularly common with smaller scripting apps).
+
+ 
+
+
+ Presale
+MonkeyUser 18 02 2020
+
+
+ Home server and Pi-hole
+Posts on James Routley 17 02 2020
+
+
+ How to write things people actually want to read
+James Sinclair 17 02 2020
+
+
+ Analytics server
+Posts on James Routley 16 02 2020
+
+
+
+
+ PWA y aplicaciones móviles con Guillermo Tamborero
+República Web 15 02 2020
+Para este episodio contamos con la compañía de Guillermo Tamborero, desarrollador y socio fundador de la empresa iproject.cat, especialistas en desarrollo proyectos web a medida, Progressive Web Apps y soluciones basadas en PHP, WordPress, Laravel y VueJS. Con Guillermo hablamos de las Aplicaciones Web Progresivas (PWA), en qué consisten y cómo encajan en el ecosistema de desarrollo web. Hablamos de las ventajas que ofrecen, cómo empezar tu propia PWA y también los inconvenientes que puedes tener en su desarrollo.
+En el episodio hablamos sobre el escaso interés de Apple en desarrollar junto con Google, soluciones estándar para PWA. Y es que Apple a pesar de ser una de las primeras compañías en apoyar la tecnología, ha decidido desmarcarse ofreciéndole un soporte limitado. Trabajar con una Aplicación Web Progresiva ofrece una experiencia muy similar a realizarlo con una aplicación nativa, pero con la ventaja de estar en un entorno idéntico al del navegador web. Como explica Guillermo, empezar a realizar tu propia PWA es tan fácil como instalar un plugin de WordPress. Otra característica de las PWA es que es posible instalarlas en casi cualquier dispositivo que admita un navegador web (en especial los basados en Chromium).
+Por último hablamos de las diferentes opciones que tenemos para desarrollar una aplicación móvil, con soluciones que van desde las opciones nativas para Android y iOS, a soluciones híbridas (Cordova, Ionic… Capacitor) o «pseudo nativas» como Xamarin, React Native, Flutter o NativeScript.
+Andros tuvo la oportunidad de coincidir con Guillermo en la pasada WordCamp de Zaragoza donde ofreció una charla sobre la edición con bloques en WordPress usando BlockLab.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Mobile viewports
+Posts on James Routley 15 02 2020
+
+
+ This website has small text on Firefox for mobile
+Posts on James Routley 14 02 2020
+
+
+ Kairos, patrocinador Gold de FrontFest 2020
+FrontFest 14 02 2020
+
+
+ How do .epubs work?
+Posts on James Routley 13 02 2020
+
+
+
+
+ Introducción al testing web por David Vaquero
+República Web 12 02 2020
+El audio de este episodio está extraído de una clase que realizó David Vaquero en un curso sobre Python. En la clase se ofrece una introducción a la teoría del testing y herramientas que se utilizan para probar el código de un sitio web. Es un contenido que te ayudará a entender en qué consiste el testing y cómo encaja en el desarrollo web.
+Puedes ver la charla en el canal de YouTube de Cursos de Desarrollo y acceder a más contenido incluyendo cursos gratuitos, en la página web de David Vaquero https://cursosdedesarrollo.com/
+ +Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ A gratitude journal design
+Posts on James Routley 12 02 2020
+
+
+ January 2020 Monthly Update
+News on Clojurists Together 11 02 2020
+
+
+ Building an IVR System with Python, Django and Twilio
+Haki Benita 11 02 2020
+Last year my team and I worked on a very challenging IVR system. After almost a year in production and thousands of processed transactions, I teamed up with the great people over at the Twilio blog to write an introductory tutorial for developing IVR systems using Django and Twilio IVR.
+
+
+ Paradigma Digital, tecnología con un propósito para un mundo mejor
+FrontFest 11 02 2020
+
+ 
+
+
+ Minor Change
+MonkeyUser 11 02 2020
+
+
+ Understand Group by in Django with SQL
+Haki Benita 10 02 2020
+Understand GROUP BY in Django ORM by comparing QuerySets and SQL side by side. If SQL is where you are most comfortable, this is the Django GROUP BY tutorial for you.
+
+
+
+
+ Geografía de la muerte
+Sección Materia | Ciencia en EL PAÍS 09 02 2020
+
+
+ mmv, a tool for batch renaming files
+Posts on James Routley 09 02 2020
+
+ 
+
+
+ Innovando en ordenadores personales con Alejandro López CEO de Slimbook
+República Web 08 02 2020
+Nos trasladamos a las instalaciones de la empresa valenciana Slimbook, fabricante de excelentes ordenadores personales especializados en GNU/Linux. Para ello nos recibe Alejandro López, CEO de Slimbook para explicarnos con detalle la filosofía de la empresa, basada en ofrecer productos de excelente calidad, combinados con un soporte cercano y profesional. A pesar de su juventud, Slimbook cuenta con un catálogo muy completo de productos, que incluyen portátiles ultrabooks, equipos de escritorio y compactos. Slimbook proporciona un cuidado montaje de los componentes y trabaja con marcas líderes como Intel y Samsung para la fabricación de sus equipos.
+
Con Alejandro hablamos también de la vocación de comunidad de la empresa y su Linux Center, una aula dedicada a fomentar el código abierto y el entorno GNU/Linux. Slimbook ofrece una combinación excelente de software y hardware, lo que garantiza que sus equipos tengan una experiencia de usuario muy elevada. Finalmente nos cuentan sus planes de futuro, las mejoras que tienen en mente y alguna colaboración que pactamos para el futuro.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Writing daily, one week in
+Posts on James Routley 08 02 2020
+
+
+ Breadcrumbs
+Posts on James Routley 07 02 2020
+
+
+ Plain Concepts, patrocinador Platinum FrontFest 2020
+FrontFest 07 02 2020
+
+
+ Blog UI updates
+Posts on James Routley 06 02 2020
+
+
+ Vim diff
+Posts on James Routley 05 02 2020
+
+ 
+
+
+ Lanzando Launchyoo una red social alternativa con Vicente Pechuán
+República Web 05 02 2020
+El mundo de las redes sociales está dominado por grandes empresas tecnológicas, con audiencias de millones de personas y presupuestos gigantes. Estas redes sociales están diseñadas para explotar la atención, los datos y el tiempo de los usuarios. En este escenario ha surgido hace poco una red social llamada Launchyoo y que se presenta como una red social alternativa y pensada con el usuario en el centro.
+
Hablamos con Vicente Pechuán, un valenciano que tras pasar por el mundo del motociclismo, decidió crear desde cero la red social que le gustaría. Vicente nos cuenta en esta entrevista los orígenes de Launchyoo, sus motivaciones y lo que le hace diferente a las redes sociales existentes. Con Vicente hablamos de la dificultad de lanzar un proyecto en un mercado tan maduro y también de cómo han orientado la aplicación de una forma integral, integrando originales funcionalidades y pensando en nuevas formas de organizar tu contenido.
+++Launchyoo es otro ejemplo de empresa con base tecnológica que puede lanzar su producto gracias a las tecnologías en la nube, que facilitan el despliegue y la flexibilidad de recursos. También de una empresa distribuida en un equipo en remoto.
Con Vicente también hablamos del futuro de Launchyoo y cómo afrontan los próximos meses. Launchyoo es una red social con un equipo distribuido y orientado al mercado hispanohablante, aunque también está disponible en varios idiomas. Dispone de un soporte para varios tipo de contenido, grupos, páginas de marcas y empresas y también permite diferenciar entre contactos.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ ¿La actividad física puede regenerar neuronas?
+Sección Materia | Ciencia en EL PAÍS 05 02 2020
+
+
+
+
+ Lo que he aprendido: la clase standalone
+Onda Hostil 04 02 2020
+
+
+ Real vs percieved simplicity
+Posts on James Routley 04 02 2020
+
+
+
+
+ Cuando el enfermo paga la investigación de su dolencia
+Sección Materia | Ciencia en EL PAÍS 04 02 2020
+
+
+ ING, patrocinador Gold en FrontFest 2020
+FrontFest 04 02 2020
+
+
+ CO2 emissions on the web
+Danny van Kooten 03 02 2020
+I’ve spent the last month trying to reduce the carbon footprint of the websites I have (some) control over. When talking about this with other people they often look at me blankly before asking “aren’t you taking this a little too far?”.
+ +The simple answer is no. In fact, it is probably the most effective use of my time when it comes to reducing carbon dioxide emissions.
+ +Just last week I reduced global emissions by an estimated 59.000 kg CO2 per month by removing a 20 kB JavaScript dependency in Mailchimp for WordPress. There’s no way I can have that kind of effect in other areas of my life.
+ +CO2 emissions from distributed code
+ +All of my WordPress plugins combined run on well over 2 million different websites, each website receiving who knows how many visitors.
+ +At an average energy expenditure of 0,5 kWh per GB 1 of data transfer this means that every kB equals 0,5 kWh / 1.000.000 kB * 2.000.000 websites = 1 kWh if each of these websites received exactly 1 visitor.
Let’s assume the average website receives about 10.000 unique visitors per month and serves files from cache for returning visitors. The total amount of energy saved by shaving off a single kilobyte is then 1 kWh * 10.000 visitors = 10.000 kWh.
10.000 kWh of energy produced by the current European electricity grid equals about 10.000 * 0,295 = 2950 kg of CO2.
++ +Shaving off a single kilobyte in a file that is being loaded on 2 million websites reduces CO2 emissions by an estimated 2950 kg per month.
+
To put this into perspective, that is the same amount of CO2 saved each month as:
+ +-
+
- Driving my Toyota Yaris for 18.670 kilometers. (158 g CO2 per km) +
- 5 flights from Amsterdam to New York. (679 kg CO2 per flight) +
- Eating 118 kg of beef (25 kg CO2 per kg of beef) +
I already work from home, am a vegetarian and didn’t take any flights in the last 3 years so it seems I am stuck trying to make the web more efficient.
+ +What can we do?
+ +According to httparchive.org, the average website on desktop is about 4 times as large as in 2010. On mobile, where data transfer is way more expensive in terms of energy usage, the numbers look even worse: from 200 kB up to a whopping 1,9 MB!
+ +As web developers we have a responsibility to stop this madness. Did websites really get 4 times as good? Is this motherfuckingwebsite.com clocking in at 5 kB in total really that bad in comparison? I don’t think so.
+ +Whenever you are adding to a website, ask yourself: is this necessary? If not, consider leaving it out.
+ +Your content site probably doesn’t need JavaScript. You probably don’t need a CSS framework. You probably don’t need a custom font. Use responsive images. Extend your HTTP cache lifetimes. Use a static site generator or wp2static.com instead of dynamically generating each page on the fly, despite never changing. Consider ditching that third-party analytics service that you never look at anyway, especially if they also happen to sell ads. Run your website through websitecarbon.com. Choose a green web host.
+ +I’m sorry if that turned into a bit of a rambling, but I hope you see where I am going with this.
+ +Personally I constrained myself to not use more than 1 kB of CSS for the website you are reading this on. And I really liked making that work, it sparked creativity.
+ +Let’s do our share as web developers and stop bloating the web.
+ ++ +
+ Energy costs of data transfer varies a lot depending on the type of network that is used. The range seems to be from 0,08 kWh per GB for fixed broadband connections to 37 kWh per GB for 2G networks.
+ +I initially went with a global estimate of 2,9 kWh per GB in this post (the average cost per GB for 3G networks), but later changed it to 0,50 kWh per GB as I believe that is a better estimate for 2020 2. It’s hard to come up with a good estimate that works globally, but I didn’t mean for this post to be about exact numbers anyway.
+ ++The most important thing I attempted to convey is that the choices we make in developing for the web have consequences that really add up at scale. +
+ ++ +
References
+ ++
+ +1 Pihkola, H., Hongisto, M., Apilo, O., & Lasanen, M. (2018). Evaluating the energy consumption of mobile data transfer-from technology development to consumer behaviour and life cycle thinking. https://doi.org/10.3390/su10072494 +
+ ++ 2 + Aslan, Joshua & Mayers, Kieren & Koomey, Jonathan & France, Chris. (2017). Electricity Intensity of Internet Data Transmission: Untangling the Estimates: Electricity Intensity of Data Transmission. Journal of Industrial Ecology. https://doi.org/10.1111/jiec.12630 +
+ +
+
+ How I make coffee
+Posts on James Routley 03 02 2020
+
+
+
+
+ Qué tiene que decir la ciencia sobre el Apocalipsis
+Sección Materia | Ciencia en EL PAÍS 02 02 2020
+
+
+
+
+ En qué ando: enero
+Onda Hostil 02 02 2020
+
+
+ Thoughts on a scheduling todo list
+Posts on James Routley 02 02 2020
+
+
+ Bulletin Board Systems: The VICE Exposé
+Two-Bit History 02 02 2020
+
+ 
+
+
+ Gestionar meetups y desvirtualizar comunidades con Juan Simón García
+República Web 01 02 2020
+Los foros y las comunidades virtuales forman parte de internet desde casi sus inicios. La capacidad de formar parte de un grupo de manera virtual, con o sin tu nombre real, ha propiciado la interacción y el intercambio de ideas de una forma antes desconocida. Si bien internet, por su facilidad y conveniencia, es una herramienta ideal para crear comunidades, la cosa se complica cuando se desea trasladar ese dinamismo digital al mundo físico.
+En este episodio queremos hablar de experiencias creando y desvirtualizando comunidades en internet. Para ello nos acompaña de nuevo en el podcast Juan Simón García, consultor y formador en nuevas tecnologías y presidente de la Asociación Valenciana de Realidad Extendida (AVRE).
+
Juan lanzó hace un tiempo una comunidad alrededor de la realidad virtual en Valenccia, con un grupo de meetup y Telegram . Con él hablaremos de esto de desvirtualizar comunidades creadas en internet, algunas experiencias y por supuesto nuestra opinión alrededor de este tema. Juan comparte los puntos positivos de crear comunidades pero tampoco oculta, la responsabilidad personal que involucra dedicarte a proyectos abiertos.
+Entre las cuestiones discutidas en el episodio del podcast se incluyen:
+-
+
- Experiencia de Juan con el grupo de Valencia Virtual. Puntos positivos y negativos. +
- Dificultad de llevar a la gente hacia planos presenciales y formas de hacerlo mejor. +
- Organización de eventos presenciales (trabajo personal y dedicación). +
- Motivaciones de la gente para unirse a grupos y si son conscientes de lo que implica. +
- ¿Se debería cobrar por las membresías o establecer límites?. +
- ¿Deben las empresas mantenerse al margen de ciertas comunidades? +
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+ 
+
+
+ Conociendo HTOP
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 01 02 2020
+El comando top es conocido por muchos, por listarnos los procesos activos y la carga del sistema, y su primo el comando htop, es aún más completo.
+Si deseas instalarlo:
+[code]sudo apt install htop[/code]+
Vía codeahoy os dejamos 2 imagenes que valen más que mil palabras:
+
+
+ Writing daily
+Posts on James Routley 01 02 2020
+
+
+ What’s more fantastic than fantasy land? An Introduction to Static land
+James Sinclair 29 01 2020
+
+
+ What’s more fantastic than fantasy land? An Introduction to Static land
+Web Development - James Sinclair 29 01 2020
+
+ 
+
+
+ Open Space
+MonkeyUser 28 01 2020
+
+ 
+
+
+ Next Level
+MonkeyUser 28 01 2020
+
+
+
+
+ Los satélites que vigilan el mar
+Sección Materia | Ciencia en EL PAÍS 26 01 2020
+
+
+
+
+ Ingenieros de hace 1,8 millones de años
+Sección Materia | Ciencia en EL PAÍS 26 01 2020
+
+
+ Q1 2020 Funding Announcement
+News on Clojurists Together 25 01 2020
+
+
+
+
+ Sitesauce, convertir sitios dinámicos en estáticos con Miguel Piedrafita
+República Web 25 01 2020
+Volvemos a contar de nuevo para este episodio con el «indie hacker» Miguel Piedrafita, que ya estuvo con nosotros en un episodio y que hoy vuelve para contarnos su último proyecto, Sitesauce. Este innovador servicio web que permite transformar un sitio dinámico basada en servidor, como por ejemplo un CMS hecho con WordPress, en un servicio estático. Esto permite aprovechar las ventajas de velocidad y seguridad que ofrecen los sitios estáticos, pero al mismo tiempo manteniendo el panel de control y la organización de los sitios basados en gestores de contenido.
+El SSR o server side rendering consiste en alojar archivos estáticos listos para servir y sin intervención de base de datos o una lógica de procesamiento. Miguel viene a contarnos más sobre su proyecto, cómo se le ocurrió este servicio y los casos específicos donde su solución puede ser más interesante. Miguel habla de las tecnologías usadas y además nos cuenta detalles sobre el proyecto. También le preguntamos consejos sobre como arrancar tu propio proyecto en internet.
+En la segunda parte del podcast volvemos con la sección Radar donde hablamos de recursos, herramientas y tecnologías interesantes en el mundo del desarrollo web.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ La banquera que salva vidas
+Sección Materia | Ciencia en EL PAÍS 24 01 2020
+
+
+
+
+ Las mejores imágenes científicas del año
+Sección Materia | Ciencia en EL PAÍS 24 01 2020
+
+
+
+
+ “Muy pocos políticos se interesan de forma auténtica por la ciencia”
+Sección Materia | Ciencia en EL PAÍS 23 01 2020
+
+
+
+
+ APP en VueJS con la ayuda del API REST de WordPress – Andros Fenollosa en WordCamp Zaragoza 2020
+República Web 22 01 2020
+En el evento de WordPress WordCamp Zaragoza nuestro compañero Andros Fenollosa tuvo la oportunidad de participar con dos charlas. En esta charla Andros demuestra las bondades del API REST de WordPress para agilizar la ejecución de proyectos web. En este caso Andros cuenta como la API de WordPress le ayudó a alimentar una APP que tuvo que realizar en su estudio en poco tiempo.
+En la charla Andros también cuenta como se ayudó de VueJS y de las herramientas que incorpora, además de detalles sobre como construir la aplicación.
+Audio extraído del vídeo de la charla disponible WordPress.tv.
+
+
Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ ¿Es seguro que existe la materia oscura?
+Sección Materia | Ciencia en EL PAÍS 22 01 2020
+
+
+ Effective Collaboration with Product and Design
+Josh Comeau's blog 21 01 2020
+
+ 
+
+
+ User Story
+MonkeyUser 21 01 2020
+
+
+
+
+ Charla sobre podcasting en la meetup de WordPress Valencia
+Javier Archeni 20 01 2020
+
+
+
+
+ El espacio, parque de atracciones de los milmillonarios
+Sección Materia | Ciencia en EL PAÍS 19 01 2020
+
+
+
+
+ Clouding.io, el cloud también habla español con Patricia Armesto
+República Web 18 01 2020
+El cloud sigue imparable y cada vez son más los proveedores que ofrecen soluciones de calidad con grandes prestaciones a un precio muy competitivo. Clouding.io es una empresa que ofrece servidores cloud vps con sello español desde su centro de datos en Barcelona. Para este episodio contamos con Patricia Armesto, del equipo de comunicación, marketing y comunicación con el cliente de Clouding.io. Con Patricia hablamos sobre lo que ofrece desde España clouding.io en el mercado del cloud, sus características más destacables y cuestiones como el tipo de proyectos que se lanzan desde su infraestructura.
+El nombre de Clouding ya ha surgido en alguno de nuestros episodios y hay que destacar los excelentes resultados que obtiene en rendimiento. Clouding se caracteriza por un acento especial en la atención al cliente y en una infraestructura de primer nivel 100% en Barcelona. A destacar también su facilidad de uso y la opción de comenzar gratuitamente con un acceso abierto para probar su servicio con 5 euros de crédito. Además clouding.io no sólo opera con clientes en España, sino que sus servicios también son contratados por clientes internacionales.
+Con Patricia Armesto tratamos las siguientes cuestiones:
+-
+
- Orígenes de clouding.io +
- Como están viviendo el auge del cloud en la empresa española. +
- Características más destacables que ofrece clouding a sus clientes. +
- Tipo de cliente que confía en sus servicios y qué tipo de proyectos suelen montar. +
- Su servicio de administración y soporte Cloud Pro. +
- Planes de futuro. +
Estamos agradecidos al equipo de clouding.io por la atención prestada desde el primer momento y como se comenta en la entrevista, les emplazamos a nuevas colaboraciones que ayuden a conocer las posibilidades del cloud español para los desarrolladores y proyectos empresariales.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ Una tinta de oro y azúcar fundamental para tratar el cáncer
+Sección Materia | Ciencia en EL PAÍS 17 01 2020
+
+
+
+
+ Meetup WordPress Valencia – Hola soy WordPress y he venido a salvar al podcasting
+República Web 16 01 2020
+Como episodio especial del podcast, subimos la grabación de la intervención de Javier Archeni en el Meetup de WordPress Valencia celebrado este miércoles 15 de enero en las instalaciones de IEM Business School. La charla tuvo como objetivo presentar las oportunidades que ofrece el podcasting y cómo garantizar la independencia de tus contenidos, sin renunciar a la exposición que ofrecen las plataformas de streaming.
+En la charla se destacó el crecimiento sostenido que ha venido experimentando el podcasting y los diferentes actores que protagonizan al medio. Debido a que se trata de una presentación en el Meetup de WordPress Valencia, se explica los puntos básicos a tener en cuenta para crear tu podcast con este software. Además se ofrece una visión del futuro del podcasting y el escenario que afrontamos como productores de contenido.
+ +Descargar presentación en formato PPTX editable (Mega).
+Desde aquí agradecer al equipo de organización del evento, con Ricardo Vilar a la cabeza la oportunidad para participar en el encuentro. También a los patrocinadores del evento por el apoyo brindado para su celebración (Siteground, Weglot) Confiamos poder seguir colaborando con nuevos eventos que acerquen la tecnología a los profesionales de los contenidos y el desarrollo web.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ El ídolo de Pachacámac, un caso excepcional de pintura policromática
+Sección Materia | Ciencia en EL PAÍS 15 01 2020
+
+
+
+
+ Andar rápido modifica el ADN y reduce el riesgo cardiovascular
+Sección Materia | Ciencia en EL PAÍS 14 01 2020
+
+
+
+
+ Hallado un material más antiguo que la Tierra dentro de un meteorito
+Sección Materia | Ciencia en EL PAÍS 14 01 2020
+
+ 
+
+
+ 32 consejos para web developers
+Blog de Diseño Web Vida MRR 14 01 2020
+¿Qué consejo le darías a un desarrollador web? seguramente si tienes ya un poco de experiencia sabrás que hoy en día un developer no solo debe centrarse en el tema del código como tal, hay varias habilidades adicionales que se necesitan para tener en cuenta que un desarrollador web tiene un perfil más completo.
En este video les comparto 32 consejos para web developers, consejos muy rápidos y sencillos de seguir si tu ruta de carrera conlleva tener un puesto de este tipo, pues temas de colaboración, de apoyo a la comunidad, de tener presencia en internet y de estar constantemente actualizándose con las nuevas tecnologías son temas importantes que necesitas cumplir para tener un perfil completo.
+ 
+
+ 
+
+
+ Fix
+MonkeyUser 14 01 2020
+
+
+
+
+ Un coágulo en la yugular de un astronauta obliga a la NASA a improvisar una cura en órbita
+Sección Materia | Ciencia en EL PAÍS 13 01 2020
+
+
+
+
+ Cómo se hace un biobot
+Sección Materia | Ciencia en EL PAÍS 13 01 2020
+
+ 
+
+
+ 10 ejemplos de diseños web enfocados a la música
+Blog de Diseño Web Vida MRR 13 01 2020
+
Hace tiempo que no comparto diseños de sitios web. En esta ocasión les comparto una galería de diseños de sitios web con estilo enfocado a la música. Muchos de estos sitios obviamente tienen que ver con artistas o la fuente hace referencia mucho al tipo de música que vas a encontrar. Sitios que se enfocan en colecciones de música o servicios de streaming están enfocados en dar a conocer los éxitos más populares alrededor del mundo, por lo que son varios los tips que pueden tomar como referencia si su próximo proyecto va a ir enfocado a la música.
2. Slide:
3. Mixtape:
4. Milando:
5. BeatsWave:
6. SoundFlare:
7. Bepop:
8. Mousiqua:
9. Bridge:
10. Kentha:
+ 
+
+
+ Magical Rainbow Gradients
+Josh Comeau's blog 13 01 2020
+
+
+
+
+ Ciencia, las dudas de un ministerio amputado
+Sección Materia | Ciencia en EL PAÍS 13 01 2020
+
+
+
+
+ Minerales con leyendas de deseos, amor y muerte
+Sección Materia | Ciencia en EL PAÍS 13 01 2020
+
+
+
+
+ El viaje en el tiempo como truco cuántico
+Sección Materia | Ciencia en EL PAÍS 12 01 2020
+
+
+
+
+ Estudio sobre los frameworks de Front-end más utilizados
+República Web 11 01 2020
+Para este primer episodio del año, queremos continuar hablando del estudio de tecnologías web realizado por David Vaquero. En esta ocasión vamos a detenernos en los datos que ha conseguido David en relación a los frameworks de front-end. Veamos si hay sorpresas en las tecnologías más usadas y si podemos ver alguna tendencia clara en los datos que ha obtenido David.
+Antes de empezar el episodio 123, hablamos de la creación del grupo Malditos Webmasters en Telegram. Se trata de un espacio para todas aquellas personas interesadas en la creación y mantenimiento de un sitio web. También hablamos de nuestras próximas charlas en meetup WordPress Valencia y WordCamp Zaragoza. Por último también comentamos nuestras expectativas y propósitos para el año que comenzamos.
+Con respecto a las tecnologías de front-end, poca sorpresa al encontrarnos a jQuery como el dominador absoluto en este terreno. Una cuestión importante es advertir que son datos obtenidos de vistas públicas procedentes de dominios facilitados por Alexa. No se muestran los datos procedentes de sitios web protegidos por contraseña o que pueden estar detrás de algún proxy o cortafuegos. Hablamos sobre React, Vue y también sobre Angular. Ofrecemos también unos datos sobre las demandas laborales en este terreno.
+En la segunda parte del episodio volvemos con la sección Radar, con interesantes recursos propios y de terceros. Disponibles los enlaces en la sección inferior.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+
+
+ Historia profunda del tomate
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+
+
+
+ Gusanos, microbios y desechos que resucitan suelos
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+
+
+
+ El cambio climático avivará los incendios en la selva amazónica
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+
+
+
+ Anillo de fuego
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+
+
+
+ El viaje de una fruta diminuta nacida en los Andes que conquistó el mundo
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+
+
+
+ ¿Por qué nuestra galaxia tiene forma de espiral?
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+
+
+
+ Las 10 especies de pájaros recién descubiertas que desaparecerán en 20 años
+Sección Materia | Ciencia en EL PAÍS 10 01 2020
+
+ 
+
+
+ Cómo hibernar en Ubuntu 18.04 LTS, 19.10, 20.04, o Linux Mint y derivadas.
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 09 01 2020
+AVISO IMPORTANTE: Las distintas distribuciones de GNU/Linux han quitado la opción de hibernar, porque genera muchos problemas. tanto de incompatibilidad con mucho ordenadores, como fallos puntuales. Nosotros hemos probado y ahora mismo funciona, pero no sabemos si después de una actualización de tu distribución linux, mañana por ejemplo, dejará de funcionar. Es por ello que deberás asegurarte cuando hibernes, que el ordenador está completamente apagado, antes de meterlo en un maletín y que se sobre-caliente.
Para poder activar la hibernación en tu portátil, lo primero que debes saber es que has de tener en la bios desactivado el Secure Boot, y has de haber instalado así el sisetma operativo, no se puede cambiar a las bravas. Y lo segundo que has de saber es que vas a perder un trozo de disco duro, ya que has de reservar el espacio. Aunque desde Ubuntu 18 ya no hay partición swap, si no un fichero pequeño y dinámico, ahora has de fijarle un tamaño, concretamente el tamaño de tu memoria RAM (o algo más por precaución).
+Puedes mirar gráficamente cuanta RAM tiene tu ordenador, o puedes comprobarlo via terminal con:
+[code]free[/code]+
Del comando de arriba quedarte con el primer valor de memoria, o si quieres usa este otro comando:
+[code]vmstat -s | awk '{print int(($1 / 1024 / 1024)+0.51)}' | head -1[/code]
+Si tuvieras la swap ya activa, primero hemos de detenerla, para poder luego redimensionarla. Detenla con este comando:
+[code]sudo swapoff -a[/code]+
Crea el fichero de swap con el tamañao de tu ram, yo pongo en mi ejemplo 16 GB, pero cambia el número por tu RAM o un poco más:
+[code]sudo fallocate -l 16g /swapfile[/code]+
Dale permisos y añadelo al fichero fstab con:
+[code]sudo chmod 600 /swapfile+
sudo mkswap /swapfile
sudo swapon /swapfile[/code]
Mira si ya tienes el el fichero /etc/fstab una linea que empiece por /swapfile, si no la tienes añadela con esto:
+[code]echo '/swapfile swap swap defaults 0 0' | sudo tee -a /etc/fstab[/code]+
Montamos y verificamos:
+[code]sudo findmnt -no SOURCE,UUID -T /swapfile[/code]+
Nos mostrará algo como esto: /dev/sda1 0c233fbb-f72e-470f-8460-4f2521bf3569
La segunda parte después de sda1 (o nvme0n1p1 o tu lvm) es el UUID de la partición y tienes que apuntártela, o copiarla.
Ahora instalamos y configuramos uswsusp:
+[code]sudo apt install uswsusp+
sudo dpkg-reconfigure -pmedium uswsusp[/code]
Te preguntará si quieres continuar sin valeidar swap, respondes "Sí".
Luego te dirá que selecciones la partición, y NO has de elegir /swapfile, y SÍ el UUID que has apuntado antes.
En cifrar la partición hibernada diremos NO para que no nos pide una contraseña adicional para desbloquarlo, con cerrar sesión que lo hace, es suficiente.
Por si acaso ahora:
+[code]sudo update-initramfs -u[/code]+
Es hora de probar si la hibernación funciona con este comando (espera un minuto):
+[code]sudo s2disk[/code]+
Estos pasos son solo para Linux Mint:
Si no ha vuelto a tu sesión después de hibernar, haz estos pasos, pero si ha ido bien, no lo hagas:
[code]sudo nano /etc/default/grub[/code]+
y añadir en la linea GRUB_CMDLINE_LINUX_DEFAULT="quiet splash", antes de cerrar las comillas resume=UUID= con el identificador de tu partición que hemos copiado antes, o sea en nuestro caso quedaría así:
+[code]GRUB_CMDLINE_LINUX_DEFAULT="quiet splash resume=UUID=0c233fbb-f72e-470f-8460-4f2521bf3569"[/code]+
[code]sudo update-grub[/code]+
[code]reboot[/code]+
Fin de los pasos para Linux Mint
+Ahora tenemos que editar el servicio de hibernación para que utilice el nuevo métido:
+[code]sudo systemctl edit systemd-hibernate.service[/code]+
Y dentro pegamos:
+[code][Service]+
ExecStart=
ExecStart=/usr/sbin/s2disk
ExecStartPost=/bin/run-parts -a post /lib/systemd/system-sleep[/code]
Volvemos a probar la hibernación, pero ahora con el servicio:
+[code]systemctl hibernate[/code]+
Si no funciona puedes ver el estado y ver los errores que muestra:
+[code]systemctl status systemd-hibernate.service[/code]+
Ahora que todo funciona correctamente, sólo tenemos que al apagar el ordenador, aparezca la opción de hibernar junto a la de reiniciar o suspender.
Vamos a crear un fichero nuevo con:
[code]sudo nano /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla[/code]+
y dentro pagamos a pegar esto y guardar:
+[code][Re-enable hibernate by default in upower]+
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes
[Re-enable hibernate by default in logind]
Identity=unix-user:*
Action=org.freedesktop.login1.hibernate;org.freedesktop.login1.hibernate-multiple-sessions
ResultActive=yes[/code]
Ahora reiniciamos el ordenador y ya estará listo :)
Adicionalmente en Gnome Shell existen extensiones como esta para que el botón esté más accesible.
+
+
+
+
+ Cae la confianza de los españoles en la innovación, sobre todo en los colectivos vulnerables
+Sección Materia | Ciencia en EL PAÍS 09 01 2020
+
+
+
+
+ La mala calidad del sueño despierta al alzhéimer
+Sección Materia | Ciencia en EL PAÍS 09 01 2020
+
+
+
+
+ Primer avance en décadas en un problema aparentemente imposible
+Sección Materia | Ciencia en EL PAÍS 09 01 2020
+
+
+
+
+ De Hércules de feria a ganador del Nobel
+Sección Materia | Ciencia en EL PAÍS 09 01 2020
+
+
+
+
+ La primera especie extinguida de 2020: un pez de hasta siete metros de largo
+Sección Materia | Ciencia en EL PAÍS 09 01 2020
+
+
+ Q1 2020 Survey Results
+News on Clojurists Together 09 01 2020
+
+
+
+
+ Dos misiones para desentrañar el misterio de los agujeros negros
+Sección Materia | Ciencia en EL PAÍS 08 01 2020
+
+
+
+
+ Detectada la mayor colisión estelar del universo
+Sección Materia | Ciencia en EL PAÍS 08 01 2020
+
+
+ State of Clojure 2020 Survey
+Clojure News 07 01 2020
+
+
+It’s time for the annual State of Clojure Community Survey!
+
+
+If you are a user of Clojure or ClojureScript, we are greatly interested in your responses to the following survey:
+
+
+-
+
- + + +
+
+The survey contains five pages:
+
+
+-
+
-
+
General info
+
+ -
+
Tool usage
+
+ -
+
Questions specific to JVM Clojure (skip if not applicable)
+
+ -
+
Questions specific to ClojureScript (skip if not applicable)
+
+ -
+
Final comments
+
+
+
+
+ The survey will close January 23rd, after which all of the data will be released with some analysis. We greatly appreciate your input!
+
+ 
+
+
+ Qué es CORS y cómo usarlo en Node.js
+Blog de Diseño Web Vida MRR 07 01 2020
+CORS significa Cross-Origin Resource Sharing, y es una política a nivel de navegador web que se aplica para prevenir que el dominio A evite acceder a recursos del dominio B usando solicitudes del tipo AJAX como cuando usamos
fetch() o XMLHttpRequest.Un ejemplo básico de este comportamiento es cuando creas un archivo html y tratas de hacer una llamada AJAX a cualquier sitio en internet o servidor en tu equipo o red local. Vas a obtener un error como el siguiente:
Puedes encontrar toda la información detallada en el sitio de Mozilla pero en este tutorial vamos a ver cómo manejar este comportamiento con Node.js
Lo primero que necesitamos saber es que si tenemos dos dominios: posco.com y contaro.com en principio no pueden comunicarse. Si nosotros queremos que por ejemplo contaro.com pueda permitir a otros dominios acceder a sus recursos, podemos hacerlo a través del módulo de cors. Lo primero es instalarlo
$ npm install cors
Después, vamos a incluirlo en nuestro archivo de Node.js
var express = require('express')
var cors = require('cors')
var app = express()
app.use(cors())
app.get('/products/:id', function (req, res, next) {
res.json({msg: 'This is CORS-enabled for all origins!'})
})
app.listen(80, function () {
console.log('CORS-enabled web server listening on port 80')
})
var whitelist = ['http://example1.com', 'http://example2.com']
var corsOptions = {
origin: function (origin, callback) {
if (whitelist.indexOf(origin) !== -1) {
callback(null, true)
} else {
callback(new Error('Not allowed by CORS'))
}
}
}
...
app.get('/products/:id', cors(corsOptions), function (req, res, next) {
res.json({msg: 'This is CORS-enabled for a whitelisted domain.'})
})
+ 
+
+ 
+
+
+ Features
+MonkeyUser 07 01 2020
+
+
+
+
+ “Si no te preocupas por las plantas, es posible que no sepas cuidar de otro ser humano”
+Sección Materia | Ciencia en EL PAÍS 06 01 2020
+
+
+
+
+ El yaguareté regresa al chaco argentino
+Sección Materia | Ciencia en EL PAÍS 06 01 2020
+
+
+
+
+ Localizado el estallido de radio más cercano a la Tierra
+Sección Materia | Ciencia en EL PAÍS 06 01 2020
+
+
+
+
+ El ADN en el lugar del crimen se chiva del origen del asesino y de su color de piel, de ojos y de pelo
+Sección Materia | Ciencia en EL PAÍS 05 01 2020
+
+
+
+
+ 2020: invasión en Marte
+Sección Materia | Ciencia en EL PAÍS 05 01 2020
+
+
+ Friend of a Friend: The Facebook That Could Have Been
+Two-Bit History 05 01 2020
+
+
+
+
+ Dionisio el Exiguo
+Sección Materia | Ciencia en EL PAÍS 04 01 2020
+
+
+
+
+ Feliz 2070
+Sección Materia | Ciencia en EL PAÍS 03 01 2020
+
+
+
+
+ La física matemática que probó que el futuro del universo está bien definido
+Sección Materia | Ciencia en EL PAÍS 03 01 2020
+
+
+
+
+ El mensaje galáctico
+Sección Materia | Ciencia en EL PAÍS 03 01 2020
+
+
+
+
+ En qué ando: diciembre
+Onda Hostil 01 01 2020
+
+
+ November/December 2019 Monthly Update
+News on Clojurists Together 31 12 2019
+
+ 
+
+
+ Personal goals for 2020
+Danny van Kooten 30 12 2019
+My last blog post where I defined goals for the upcoming year was back in 2013.
+ +It’s fun to go through that post. In a way I feel some shame of where I was back then (which is silly, but I feel it nonetheless). At the same time it’s a testament of how far I’ve come, so there is some proud as well.
+ +Since this will be another post in which I will be defining my goals for the upcoming year, I hope to be looking at this post a few years from now with the same mix of feelings.
+ +For the last few years I have been drifting, just taking life as it happened. Caring for my daughter (now daughters!), keeping the business running, trying to stay healthy while attempting to enjoy life at the same time.
+ +But I miss having clear and measurable goals. I like the feeling of moving closer to a set target each and every day, even if just a tiny bit. That’s why I came up with this list of what I would like to achieve in 2020.
+ ++ +
Hire a WordPress developer
+ +I’ve postponed this for years, only hiring to help reduce the burden of daily support.
+ +Despite it being justified financially to bring on another WordPress developer to help me out with more advanced support questions and possibly some development, I’ve yet to take the plunge.
+ +For 7 straight years I have been answering emails for the Mailchimp for WordPress plugin each and every day, with at most 48 hours of rest in between. This has certainly taken its toll, so I would like to get some help in this area or alternatively sell off the product in its entirety.
+ +Learn Rust
+ +After learning Go (and open-sourcing Browserpass) in 2016 and some C in 2019, I would like to gain a basic understanding of Rust in 2020.
+ +This goal is a little vague as it is, so I will need to rephrase this goal by setting out to create a specific tool in Rust instead. More on that later.
+ +Lead climb in nature
+ +In the spring of 2020 I will be taking lessons in lead climbing. The plan is to use our summer holiday to go lead climbing in nature. Slovenia is tempting, but I am not sure whether we are ready to make the 12-hour drive with 2 young kids aboard.
+ +There are so many spots in Europe to go lead climbing that finding a beautiful place closer to home shouldn’t be an issue though.
+ +
Send a bouldering route graded 6C (V6)
+ +Another climbing related goal is to send an indoor bouldering route graded 6C. After just a few months of climbing I’m currently climbing 6B on a good day, so this should not be an issue if I put in consistent sessions and do not injure myself.
+ +Get my chess ELO rating up to 1600
+ +I have been slacking when it comes to chess lately, not playing any games at all for months. Perhaps having a clear goal will help.
+ +My current ELO rating is about 1400, I would like to get this up to 1600 in 2020.
+ +Not buying a new laptop
+ +My current laptop is a 2013 Macbook Pro, which is still running great. Despite that I have been feeling the urge to replace it lately, even though it is not even my daily driver.
+ +I gave in to the urge last month and bought a Dell XPS 15”, only to return it a week later because I realised it was an unnecessary purchase. So for 2020 (and beyond) the goal is to hold on to the Macbook Pro until it literally falls apart.
+ ++ +
If you’re still reading this far (and even if not), here’s to a wonderful 2020 for you and your loved ones.
+ +Send me a tweet if you have written goals you would like me to remind you of as the year progresses, it would be good to keep each other accountable!
+ +
+
+
+
+ Las Chimp Sisters
+Sección Materia | Ciencia en EL PAÍS 28 12 2019
+
+
+
+
+ Buscar fósiles humanos, ¿y eso para qué sirve?
+Sección Materia | Ciencia en EL PAÍS 28 12 2019
+
+
+
+
+ ¿Cómo se define la inteligencia en los seres vivos?
+Sección Materia | Ciencia en EL PAÍS 26 12 2019
+
+
+
+
+ Campana sobre campana (matemática)
+Sección Materia | Ciencia en EL PAÍS 23 12 2019
+
+
+
+
+ Nuestros ganadores y perdedores del mundo web en 2020
+República Web 21 12 2019
+Para finalizar el año proponemos un episodio clásico sobre tendencias para el año que entra. En esta ocasión en lugar de hacer un recorrido por las principales tendencias, vamos a hacerlo colocando a una tecnología en auge en relación a una que, por los motivos que sean, se encuentre en declive o en bajada. Cada uno de nosotros ha preparado una clasificación en dos categorías: ganadores y perdedores.
+| +? Winners + | ++? Losers + | +
|---|---|
| +Python / Adobe + | ++AMP + | +
| +Infraestructura Cloud + | ++Regulación de acceso a internet y privacidad + | +
| +HTTP3 / Microservicios + | ++MySQL / Chrome + | +
Personajes del año 2019 en la web
+En la segunda parte del programa destacaremos a los que para nosotros han sido los personajes del año, para lo bueno y para lo malo en esto del mundo de la web y de internet.
+| +? Héroes del 2019 + | ++? Villanos + | +
|---|---|
| +Guido Van Rossum + | ++Project Manager de Safari + | +
| +Quincy Larson + | ++Mark Zuckerberg + | +
| +Fernando Acero y Rasmus Lerdorf + | ++Project Managers de IE6/Edge + | +
Seguro que muchos tenéis vuestra propia lista de ganadores y perdedores para el 2019. Nos encantará conocerla y que la compartáis con nosotros.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ Finding your first remote job
+Josh Comeau's blog 19 12 2019
+
+
+
+
+ Estudio de David Vaquero sobre tecnologías que más se usan en la web
+República Web 14 12 2019
+Dedicamos este episodio a discutir sobre las tecnologías que triunfan en internet, y en especial hacerlo en el mundo del desarrollo web. Son muchas las tecnologías que están de moda, tanto en los eventos, como en la mayor parte de las empresas tecnológicas. Por eso nos gustaría hablar sobre cuál es la situación actual de la utilización de las tecnologías que se utilizan a día de hoy para que seamos conscientes de uso real en los principales sitios de internet.
+Para ello nuestro compañero David ha estado realizando un extenso estudio (datos disponibles en su sitio web) durante el último mes, utilizando la base de los principales sitios web según Alexa, en el que analiza hasta 1.400.000 sitios web para saber qué tecnologías utilizan. En este episodio del podcast David nos explica la metodología que ha usado en su estudio, las herramientas usadas y cómo ha organizado la información en su informe.
+En el episodio hablamos de tecnologías consolidadas, pero también nos han sorprendido ciertas librerías y tecnologías. Al final se trata un episodio de análisis de tecnologías web y su influencia en nuestro trabajo.
+Visita la web del podcast donde encontrarás los enlaces de interés discutidos en el episodio. Estaremos encantados de recibir vuestros comentarios y reacciones.
+Nos podéis encontrar en:
+-
+
- Web: republicaweb.es +
- Canal Telegram: t.me/republicaweb +
- Grupo Telegram Malditos Webmasters +
- Twitter: @republicawebes +
- Facebook: https://www.facebook.com/republicaweb +
¡Contribuye a este podcast!. A través de la plataforma Buy me a coffee puedes realizar una mínima aportación desde 3€ que ayude a sostener a este podcast. Tú eliges el importe y si deseas un pago único o recurrente. ¡Muchas gracias!
+ + +
+
+ October 2019 Monthly Update
+News on Clojurists Together 06 12 2019
+
+
+
+
+ La cara y la cruz nutricional del café en cápsulas
+Sección Materia | Ciencia en EL PAÍS 04 12 2019
+
+
+ My experience as a remote worker
+Josh Comeau's blog 02 12 2019
+
+ 
+
+
+ ESM goes GA in Node 13.2.0, React Fiber, React Native, Expert Advice, CSS Architecture, & Lighthouse! 🛰 — Pony Foo Weekly
+Pony Foo Weekly 28 11 2019
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
ECMAScript Modules!
|
|
|
Just React Things
|
|
|
|
|
|
...rest
...rest
|
|
|
|
+ 
+
+
+ Improving Cookie Consent
+WhoTracksMe blog 27 11 2019
+
+ 
+
+
+ I Am Inevitable
+MonkeyUser 26 11 2019
+
+
+ 12 Common Mistakes and Missed Optimization Opportunities in SQL
+Haki Benita 20 11 2019
+SQL is used by analysts, data scientists, product managers, designers and many others. These professionals have access to databases, but they don't always have the intuition and understanding to write efficient queries. In an effort to make my team write better SQL, I went over reports written by non-developers and code reviews, and gathered common mistakes and missed optimization opportunities in SQL.
+
+
+ Algebraic Data Types: Things I wish someone had explained about functional programming
+James Sinclair 19 11 2019
+
+
+ Algebraic Data Types: Things I wish someone had explained about functional programming
+Web Development - James Sinclair 19 11 2019
+
+ 
+
+
+ New World
+MonkeyUser 19 11 2019
+
+ 
+
+
+ Ideas para crear aplicaciones en 2020
+Blog de Diseño Web Vida MRR 18 11 2019
+
Se acerca el fin del año 2019 y con ello la oportunidad de planear la próxima aplicación móvil para tu empresa, para tu negocio propio, o como parte de iniciativas para seguir aprendiendo. En este post les comparto algunas ideas de apps móviles que de acuerdo a las últimas tendencias en torno a desarrollo deberías aprender y/o implementar en 2020.
Apps móviles enfocas a VR
Las aplicaciones con virtual reality o realidad virtual son aquellas en donde con el uso de gafas o dispositivos inmersivos puedes ofrecer una experiencia 360 grados. Hoy en día para dispositivos Android hay muchas gafas de realidad virtual que no son necesariamente caras y que puedes usarlas para probar tus aplicaciones. Principalmente esta tecnología se ha usado para construir juegos que permitan tener esa nueva experiencia interactiva donde recreas un entorno virtual completo.Apps con bots
Los bots se volvieron un boom el año pasado y su uso se empezó a expandir desde entonces. Los bots como una herramienta de comunicación pueden ayudar mucho si por ejemplo, eres un negocio que desea tener para sus usuarios un apoyo constante de comunicación, sin necesariamente tener a una persona escribiendo los mensajes.Lo que me gusta de los bots es que puedes hacerlo tan inteligente como tu lo necesites, desde que solo tengas que seguir un flujo de comunicación seleccionando opciones, hasta que puedas entablar diálogos más complejos en voz o texto.
Apps para el cuidado de la salud
Las aplicaciones para medir el pulso, los pasos y distancia son hoy en día muy fáciles de construir. La mayoría de los smartphones modernos ya tienen incluidos algunos sensores que pueden ayudarte a monitorear diferentes aspectos del cuerpo, y si lo añades con las funcionalidades de un smartwatch el resultado puede ser mucho más interesante.Todas las apps enfocadas a salud tienen como objetivo que puedas activarte físicamente con recordatorios, juegos o metas para incentivarte de una forma divertida, por lo que para tener un diferenciador es necesario hacerlo lo más amigable y llamativo posible.
Apps con blockchain
Esta tecnología si bien empezó como una forma inteligente y segura para poder usar cripto monedas, hoy en día muchos proveedores hacen uso de esta tecnología para que tu puedas crear servicios y aplicaciones en donde la integridad de la información se mantenga a pesar de los cambios futuros que tenga. Si necesitas que los datos no se modifiquen o que no haya duplicidad en los mismos, la tecnología de blockchain puede ayudar perfecto a cumplir con esa premisa, y hoy ya es relativamente más fácil construir desarrollos sobre ella.Apps Realidad aumentada
Una simple aplicación de realidad aumentada que puedes ir haciendo es la del metro como instrumento de medida. Este ejemplo hace referencia a cómo integras elementos a un entorno físico para realizar alguna actividad. Muchos utilizan la realidad aumentada para juegos, pero así como el ejemplo del metro, podrías constuir apps enfocadas a brindar una herramienta que te ayude a combinar objetos físicos con virtuales.Conclusión
Estas son 5 tendencias que esperamos ver en 2020 enfocadas al desarrollo de aplicaciones móviles. Cada una representa sus retos y oportunidades, pero lo cierto es que hace un año que algunas de ellas apenas estaban siendo presentadas, era muy difícil poder construir aplicaciones reales, ya que teníamos falta de hardware o software en forma de SDKs que nos permitieran explotar estas tecnologías. En estos momentos que estamos por concluir el 2019 podemos confirmar que ya mucha de la tecnología para hacer estas apps no solo existe en tu teléfono, sino que ya hay muchísimas formas de aplicarlas para tener una app diferente con una interacción y tecnología moderna.
+ 
+
+
+
+
+ ¿Es necesario donar productos insanos a los bancos de alimentos?
+Sección Materia | Ciencia en EL PAÍS 12 11 2019
+
+
+ Type Classes: Things I wish someone had explained about functional programming
+James Sinclair 12 11 2019
+
+
+ Type Classes: Things I wish someone had explained about functional programming
+Web Development - James Sinclair 12 11 2019
+
+ 
+
+
+ AI Training Datasets
+MonkeyUser 12 11 2019
+
+ 
+
+
+ Introducing Koko Analytics
+Danny van Kooten 06 11 2019
+After stepping down from Fathom earlier this year, I was happy working on Mailchimp for WordPress for a good few months +before realising that I was still thinking about how to make web analytics more private.
+ +It dawned on me that part of why I was building Fathom in Go was because I wanted a break from WordPress and because I deemed it necessary to achieve good enough performance.
+ +That last part might still hold true, but when choosing not to keep track of bounce rates and the time a visitor spends on a page, things become much simpler.
+ +Add to that the following facts and an idea was born:
+ +-
+
- Adding a third-party service to your site to keep track of your visitors will never be as private as a self-hosted service. +
- The majority of WordPress users will never self-host their analytics if it’s not as easy as installing and activating a plugin. +
- WordPress powers 34.9% of the internet. That’s 34.9% of the internet owning their data, despite usually not being a developer themselves. +
That’s why I set out to built Koko Analytics, a privacy-friendly analytics plugin for WordPress that does not use any external services.
+ +
Metrics
+ +Koko Analytics currently keeps track of the following metrics:
+ +-
+
- Total site visitors +
- Total site pageviews +
- (Unique) pageviews for posts, pages, products, etc. +
- Referrers (including a built-in blacklist to filter referrer spam) +
The nice thing about running inside of WordPress is that it gives the software first-hand knowledge about what’s being tracked and allows it to offer seamless integrations, like built-in event tracking for leaving comments or any of the popular form plugins.
+ +Performance
+ +Most likely, you won’t even notice that Koko Analytics is there. Even when your site is getting hammered by a sudden burst of traffic.
+ +To achieve this, the plugin uses an append-only buffer file in which pageviews are temporarily stored until they are aggregated using a background process that runs every 60 seconds.
+ +In my tests it was able to handle well over 15.000 requests per second, meaning you don’t have to worry about being on the first page of Hacker News. PHP has really come a long way in the last few years.
+ +Downloading the plugin
+ +To make sure as many people as possible have access to Koko Analytics and any improvements made by me or others, the plugin is GPLv3 licensed and available for free download.
+ +As of yesterday, you can download Koko Analytics from WordPress.org or contribute to it on GitHub.
+ +If you’re running Koko Analytics on your WordPress site then please don’t hesitate to let me know and share your thoughts on how we can make it better.
+ +And definitely consider leaving a plugin review on WordPress.org, because as you can see we desperately need some.
+ + +
+
+ Python VS Common Lisp Workflow and Ecosystem
+Lisp journey 06 11 2019
+please see Python VS Common Lisp (it’s a static page you can find in the menu).
+ +
+
+ How Much of a Genius-Level Move Was Using Binary Space Partitioning in Doom?
+Two-Bit History 06 11 2019
+
+
+ Q4 2019 Funding Announcement
+News on Clojurists Together 05 11 2019
+
+ 
+
+
+ Burnout
+MonkeyUser 05 11 2019
+
+
+ Snippet: Manipulating Rows and Columns With ClAWK
+Lisp journey 04 11 2019
+I just discovered clawk, that +seems to originate from +lispbuilder-clawk. Its +last commit dates from 2011, typical from Lisp and that’s OK, +libraries have the right to be done, it has no useful README nor +documentation, but we can see its use in the +tests, +and the library is easily discoverable.
+ +This library seems perfect to manipulate data in rows and columns.
+ +Let’s have a quick look with this dummy txt file:
+ +1 Alice 40 40
+2 Bob 39 50
+I had a conflict when use-ing clawk, which I resolved by not
+accepting the change in the debugger.
We parse all lines, give a name to the space-delimited fields, and print them back:
+ +(for-file-lines ("test.txt")
+ (with-fields ((a b c d))
+ ($print a b c d)))
+
+1 Alice 40 40
+2 Bob 39 50
+NIL
+Let’s multiply the two last fields. If we use the regular * operator, we get a
+type error because fields are extracted as strings by default. We then
+use $*:
(for-file-lines ("test.txt")
+ (with-fields ((id name payrate hrsworked))
+ (declare (ignore id))
+ ($print name ($* payrate hrsworked))))
+Alice 1600
+Bob 1950
+NIL
+We can change the field separator with a string or a regexp, with the
+no surprising clawk:*fs* variable (FS in awk):
(for-file-lines ("test.txt")
+ (let ((clawk:*fs* "-"))
+ (with-fields ((a b c))
+ ($print a))))
+And… that’s all folks. Another tool to keep in our toolbelt.
+ +-
+
- more about awk: https://www.gnu.org/software/gawk/manual/html_node/ +
+
+ Algebraic Structures: Things I wish someone had explained about functional programming
+James Sinclair 03 11 2019
+
+
+ Algebraic Structures: Things I wish someone had explained about functional programming
+Web Development - James Sinclair 03 11 2019
+
+ 
+
+
+ Python VS Common Lisp, workflow and ecosystem
+Lisp journey 30 10 2019
+I learned Java and C at school, I learned Python by myself and it was +a relief. After 8 years working and doing side projects in Python and +JavaScript (mostly web dev, Django/Flask/AngularJS/Vuejs), I am not +satisfied anymore by the overall experience so I’m making Common Lisp my +language of choice.
+ +I am not here to compare languages themselves, but their inherent +workflow and their ecosystem. This is the article I wish I had read +earlier, when I was interested in Lisp but was a bit puzzled, because +the Lisp way always seemed different, and I couldn’t find many +voices to explain it. The Python way may not be the +most practical or effective, Common Lisp might not be a dead language. I find many “workflow +fixes”, overall improvements and hackerish possibilities on the CL side, even if sometimes the +Python tooling is superior.
+ +Let’s dive in.
+ +and thanks to the proofreaders.
+ + + +Table of Contents
+ +-
+
- Development process + + +
- Libraries + + +
- Templates +
- Deployment, Shipping +
- Performance +
- Conclusion +
- Appendix: FAQ + + +
Development process
+ +Interactivity
+ +In Python, we typically restart everything at each code change, we use
+ breakpoints: this takes some time, I find it too repetitive and boring, it requires to
+ re-manipulate data to re-reach the state we were at to analyze and
+ debug our program. We might figure out a non-standard,
+ more interactive way, but still: a web server needs to restart,
+ object instances don’t get updated after a class definition. We can get a prompt on an error (-m pdb), some tools include it (Werkzeug): a sign that it is a good thing to have. Unfortunately, it is not built-in, as in CL.
In Common Lisp, everything is much more interactive in the REPL. Even
+developing web apps. On an error, we get an interactive debugger with
+the stacktrace in our editor, we press v and voilà, we are at the
+problematic line. We can of course catch errors to avoid the debugger, or disable it with global settings. We can resume the program execution from any stackframe. No process needs to restart. The variables
+that we define on the REPL stay here. If we change a class definition
+(say, we remove a field), existing instances get (lazily) updated.
The Lisp REPL is part of the development process, it is not only used +for exploration and debugging. It’s fun, it’s a productive boost, and +it allows to catch errors earlier, both because we try functions +earlier, and because we get type warnings when we compile the file or +the current function (yes, we can compile a single function).
+ +Now, the cost is that one must learn to play with this live data. We +might come to a state that doesn’t reflect the code anymore, so we’ll +write our own “reset” functions or just restart the lisp image.
+ +Here’s a video where the developer defines a dummy interface, makes it +fail, develops it, and tests it, all quickly by interacting with the REPL.
+ + + +
Editing code
+ +Python: we edit code line by line, paragraph by paragraph. We can +try out half-backed editor plugins to edit code by semantic units. Sometimes we +must even pay attention to add a couple whitespace there, remove one +there. We are far from the immediate interactive feedback of the hacker’s +vision “Inventing on Principles”.
+ +Common Lisp: we edit code by semantic units. I love emacs’ lispy +mode, which is weird at first of course, +but so convenient. We can navigate to expressions back and forth, we +can delete a whole “if” expression with a keypress, indentation is +automatic, etc. There are other emacs plugins. Parinfer is appreciated in other editors too.
+ +Actually, we edit code by parenthesis units, which doesn’t carry as +much meaning as an Abstract Syntax Tree. For a real AST, we’d need a +code walker (like Concrete-Syntax-Tree). But since Lisp’s syntax is based on parenthesis, in +practice the experience is similar.
+ + + +I had a try on writing a little plugin to help editing Python code by manipulating +the AST (red4e). We +first need an AST parser. There was a couple for Python 2, another one +for Python 3 without type annotations, eventually one emerged a couple +years later: these are signs of an unstable language and ecosystem, and it is more work +required by the developer. I went the simple way by calling each +function into a new Python process, which is of course too +slow. traad is a better project, +it can do much more but still, it’s difficult to answer questions like +cross-referencing: “who calls this function” or “who does this +function call”, which are built-in in +SLIME. SLIME is like the Language +Server Protocol for Common Lisp in Emacs, its backend Swank being +editor-agnostic.
+ +Maybe other editors and proprietary ones come with a better +experience, at the cost of freedom, money, configuration time and +memory and CPU resources. If I have the choice, I prefer to not go +this route, and choose a better platform from the start.
+ +Traad is built around a client-http server approach, this is the idea +behind LSP… this reminds me of the architecture of SLIME! +It has a backend, Swank, and a client (SLIME for Emacs, SLIMA for Atom,…). +It thus has a modern architecture since its +inception :) It is moreover based on a stable language whose syntax +can not rot and has decades of development behind it, so we can be +confident about the tool. Saying this because it’s hard to grasp what +SLIME is at the beginning.
+ +SLIME itself is tied to Emacs, and thus a newcomer can find the UI +unpractical. Swank though can be used outside of Emacs, and it is for +example for Atom’s SLIMA, +which now has all the most important SLIME features: REPL, integrated +debugger, jump to definition, autocompletion, interactive object +inspection, and more.
+ +-
+
- more: https://lispcookbook.github.io/cl-cookbook/editor-support.html (Eclipse, Lem, Jupyter Notebook,…) +
Running, testing programs
+ +Python: the default workflow is to run commands in the
+terminal. Scroll, read the output, copy-paste manually (or use the
+non-UX-optimal termux or a terminal inside emacs), go back to your
+editor. Type commands without completion, type the whole path to a
+single unit test (pytest path/to/test.py::foo), or configure your
+editor and find a good plugin that is compatible with your test runner (I
+can’t use the excellent nose-mode :( ).
Common Lisp: the default workflow is to do everything interactively +into the REPL, but some people still use a +write-compile-run approach. Consequently there is built-in completion for +everything. We don’t have to use the shell (except from once in a +while to run global tests or build the system) and that’s a good +thing. There is an interactive debugger. We can interactively fix and re-run code and +tests.
+ +Here’s a quick demo on how to interactively fix failing tests:
+ + + +Running and debugging on a remote server: in Python, we usually rsync
+sources and run tests manually, or start vim/emacs under tmux on the
+server. We have to kill the app to reload it. In Common Lisp, we can
+connect to the running, remote instance, write changes from the
+comfort of our editor locally, hit C-c C-c on a function to compile it
+and see changes on the remote image. CL has more hackerish capacities
+here, no doubt, and I find it attractive :)
-
+
- more information on (remote) debugging: https://lispcookbook.github.io/cl-cookbook/debugging.html +
- a demo with a web app: https://lisp-journey.gitlab.io/blog/i-realized-that-to-live-reload-my-web-app-is-easy-and-convenient/ +
- watch Baggers working with OpenGL: https://www.youtube.com/watch?v=a2tTpjGOhjw&index=20&list=RDxzTH_ZqaFKI +
- a Minecraft game engine that you can change while playing: https://github.com/gmasching/sucle +
Typing
+ +Python: we catch a lot of type errors in production, and/or we have +to write a lot more unit tests. Hope we agree on this.
+ +Now we can improve the situation somehow with type annotations, +however it has the cons of being an after-thought: it is not stable +(differences between Python versions), not well integrated +(we have to run another command, choose between mypy, the new typing +module, pyre), it is not interactive, we need to configure our IDE, it +adds a start-up penalty (which might or might not be important).
+ +In Common Lisp, particularly with SBCL, we get a lot of type errors +or warnings at compile time. We can compile a single function, and +thus have an immediate feedback. We’re closer (not there, just +closer) to the “if it compiles, it works” situation (we know it runs, +since we constantly compile and try the functions). We can also create +our compound types and add type declarations to variables and +functions. It’s great, though it doesn’t do as much static checks as a +real typed language.
+ +Adding type declarations in well chosen places such as inner loops +also allows to gradually speed up the program where needed.
+ +-
+
- https://lispcookbook.github.io/cl-cookbook/type.html +
- Compile-time type checking in the programmable programming language Lisp +
- will ML embedded into CL +help even more ? +
Refactoring
+ +Python: we can’t refactor code as we want. Decorators, context +managers: they have an interface and they are limited to what they +offer. You can’t do things a bit differently, you must comply to the +interface. That might be a feature, but I prefer not being +restricted. In my experience, this leads to code repetition whereas +in CL, we can refactor how we want, and we get a cleaner code.
+ +Common Lisp: there are similar patterns than in Python, but we can +escape them. We can use macros, be concise and do what we want. We can +have the decorator syntax with the cl-annot library, and any other by +writing our reader macros (they can bring triply-quoted docstrings, +string interpolation, infix notation, C syntax…). It’s not only macros +though. The polymorphism of the object system (or generic dispatch) +helps, and Lisp’s “moldability” in a whole allows us to refactor code +exactly how we want, to build a “Domain Specific Language” to express +what we want. Other language features than macros help here, like +closures or multiple +values +(which are different, and safer for refactoring, than returning a tuple).
+ +Now, speaking about refactoring tools, they are better Python side. I
+don’t know of a Lisp tool that allows to change all the code-base
+according to the AST, maybe in a proprietary editor. There are
+utilities to make local transformations, like “extract this expression
+into a let variable at the top of the function”, “transform a
+function to a lambda equivalent” or the contrary, etc.
(edit January, 2020: the language-agnostic tool Comby will be useful here. I used it for syntactic manipulation, for example to replace a (if (…) (progn …)) by a (when (…) …)). See Colisper (a POC).
Libraries
+ +Library management
+ +pip: use virtual environments (virtualenv, virtualenvwrapper, tox, +anaconda,… or install per-user), pin dependencies (pip-tools, pipenv, poetry, +pyupdate,…). Debug problems due to +a third party library that didn’t pin its dependencies strictly +enough (happens at the wrong moment).
+ +quicklisp: think of it like Debian’s apt, shipping releases that
+work together (that load together), and that we upgrade together, when we
+want. If needed, we can still clone projects into
+~/quicklisp/local-projects/ for a system-wide installation, or have
+project-local dependencies with
+Qlot.
+Quicklisp is very slick. Libraries are installed at runtime, during
+ our REPL session. We don’t have to reload the Lisp process.
We are not even limited to Quicklisp any more (it can be limiting +because of its one month release cycle). The +Ultralisp distribution builds every 5 +minutes. clpm is a package +manager with a traditional approach. One can publish his own Quicklisp +distribution, to provide a set of packages that are known to work +together.
+ +State of the libraries
+ +CL might have more libraries than you think, see the Awesome CL +list, +http://quickdocs.org/ or do a quick search on the net. I know I am +constantly surprised.
+ +But sure, the Python ecosystem is huge. A few remarks on the differences:
+ +-
+
- Quicklisp has around 1500 packages, PyPI over than 170 000. It’s hard to imagine that there are a hundred times more useful libraries :D Even in CL we have duplication of libraries with a dozen of test frameworks. +
- Quicklisp is a curated distribution, PyPI is not. That means that +libraries that don’t compile anymore are rejected (after a notice to +the maintainers), and that orphan projects’ URL can be updated to +point to a community maintained one. +
- Anybody can easily publish a library to PyPI on its own. Less so +with Quicklisp, one must open an issue (Ultralisp doesn’t have this limitation). +
- numcl is a Numpy clone. +
- if needed, you can use py4cl and more to interface with Python. +
An important remark, is that Common Lisp is a stable language, and +that the libraries play this game (I saw a deprecation feature staying +for 12 years). We can still run code that was written in the early 90’s.
+ +Lisp’s simpler, non-rotting syntax plays a good role on +stability. Caution: that doesn’t mean the implementations don’t +evolve, quite the contrary.
+ +In his appreciated article A Road to Common Lisp, the author writes:
+ +++ + + +as you learn Common Lisp and look for libraries, try to suppress the voice in the back of your head that says “This project was last updated six years ago? That’s probably abandoned and broken.” The stability of Common Lisp means that sometimes libraries can just be done, not abandoned, so don’t dismiss them out of hand.
+
Templates
+ +Ever had headaches with Jinja ? Ever fought against Django +templates ? Ever abandoned to clean up a big mess of html and +templating code ? Used Jinja macros to factorize code ? Maybe you +turned to the good looking Jade (Pug). So you read another documentation, +you install tools to integrate it into your project. And now damn, no +more cross-files macros. You edit blocks of code whitespace by +whitespace. And in the end, your html may still not be valid…
+ +You might use Mako templates, but there’s something you can’t do.
+ +In CL, we can also use a Django-like templating engine, Djula +templates (despite its modest number +of stars, it is one of the most downloaded projects on Quicklisp). +The Mako equivalent would be Ten. +However, we can alternatively just use plain old Lisp, for example with +Spinneret. As a +consequence, we can factorize code as we always do (with spinneret functions or +lisp macros). We manipulate code as we always do. It even warns on +malformed html and has some neat features (it is clever about headers +levels, it can embed markdown, etc).
+ +Stuff like this is less possible with Python, because the language is +less flexible. The components libraries I have seen use strings inside +Python code.
+ +Deployment, Shipping
+ +Shipping an app, even more a web app, in Python (and JS) is +tedious. There are no default way to ship a self-contained +executable. Current projects aiming at fixing that can work… and may not.
+ +So the current solution is to turn to containers. They’re the Big +Thing, but we still need to spend hours on reading resources, building +the Docker file, the deployment pipeline, fixing bugs, updating the +stack, accepting security holes, etc. Hours we could put on our +app. With Docker though, users still can’t download a binary.
+ +In Common Lisp: we (re)discover the joy of a compiled language. We +compile our program to machine code, the binary embeds the run-time, the +debugger, the web server, the static assets, and we ship it. We run it on +the server and we can access it from the outside straight away.
+ +An SBCL image of a non-trivial web project will weight ± 20 to 30MB +(with core compression). For a lighter binary (not that I care +personally), we could try ECL (that compiles to C), or use +tree-shakers of proprietary implementations (LispWorks, Allegro).
+ +We can still benefit from Docker if needed, of course.
+ +Deployment process in Python: install Python and pip, install pip +dependencies and their system requirements and be prepared for errors (or try non-standard tools, +like Platter), configure a server for static files (nginx, whitenoise), run a +WSGI web server,…
+ +Deployment in CL: build your binary, send it to the server, run +it. Configure nginx eventually. We can compile and include assets into +the image (see Rock).
+ +Performance
+ +Python is notoriously slow, and passed the hobby project you quickly +realize that.
+ +Python has a Global Interpreter Lock.
+ +SBCL compiles to machine code and is garbage collected [1].
+ +We can fine-tune the types in our Lisp programs for the compiler to +make the consequent optimizations. We can run in “debugging first” or +in “speed first” modes. We can inline code to gain in the cost of +function calls.
+ +As a consequence, you may not need memcached in your Lisp project yet.
+ +-
+
- https://lispcookbook.github.io/cl-cookbook/performance.html +
- CL can be tuned to be faster than C +
- interesting stuff: +Petalisp - an attempt to +generate high performance code for parallel computers by +JIT-compiling array definitions. It works on a more fundamental +level than NumPy, by providing even more powerful N-dimensional +arrays, but just a few building blocks for working on them. +
- pgloader was re-written from Python to Common Lisp for a 30x speed gain. +
[1]: and rest assured, Google improves the GC
+ +Conclusion
+ +I hope I killed some FUD and showed you new ways to make stuff. May +that inspire you!
+ +Appendix: FAQ
+ +Some info every Python programmer will come across eventually. Saves you some googling.
+ +Are there no iterators ?
+ +In practice, we mostly rely on closures, but there are libraries to +create iterators.
+ + + +Can I define my own + operator like in an OO language ?
+
+By default, no, because the Common Lisp Object System (CLOS) came after the language specification +and thus everything isn’t object-based. However there are libraries +like generic-cl and, in +practice, we quickly forget about this. Different operators is also a +means for performance, good type inference and error messages.
+ +To which extent can Lisp be compiled, with all its dynamic nature, garbage collection, macros and what else ?
+ +Many Lisp compilers compile to machine code (SBCL, CCL, CMUCL,…).
+ +Full answer: https://stackoverflow.com/questions/913671/are-there-lisp-native-code-compilers/914383#914383
+ +But what is Common Lisp good for, really ?
+ +We have a ready-to-use citation :)
+ +++ +Please don’t assume Lisp is only useful for Animation and Graphics, AI, Bio-informatics, B2B and Ecommerce, Data Mining, EDA/Semiconductor applications, Expert Systems, Finance, Intelligent Agents, Knowledge Management, Mechanical CAD, Modeling and Simulation, Natural Language, Optimization, Research, Risk Analysis, Scheduling, Telecom, and Web Authoring just because these are the only things they happened to list. – Kent Pitman
+
Kent Pitman
+ +http://www.nhplace.com/kent/quoted.html
+ +See also http://random-state.net/features-of-common-lisp.html
+ +So why is CL not more popular ?
+ +First, some reminders:
+ +-
+
- popularity doesn’t equal quality, and popularity is hard to +measure. +
- some success stories: http://lisp-lang.org/success/ Aircraft analysis suits, Missile defense, ICAD, music composition, algebra systems, bulk importer for PostgreSQL, grammar checking, 3D editor, knowledge graphs,… +
- did you know that pgloader was re-written from Python to Common Lisp? (for a x30 speed gain, among other benefits) +
- CL was used in a spacecraft (and the REPL was used to debug the system live from the earth) +
- some companies still use and pick CL: https://github.com/azzamsa/awesome-lisp-companies, companies provide professional support (Platform.sh). +
- Google’s ITA Software still powers airfare search on Orbitz or Kaya.com, +
- reddit v1 was written in CL! JavaScript was
writtensketched in CL! (see here, with lisp code still visible in the repository: here)
+ - CL was number 2 on the Tiobe index for years in the 80s! +
That being said, my 2 cents since you ask:
+ +-
+
- I think the CL world missed the web bandwagon for some time (common-lisp.net was horrible for some years), but that’s been fixed. +
- an enormous code-base existed before GitHub. +
- we missed visually nice, practical content on the web, even though +there are many books. It’s a bit better now. +
- CL missed a package manager for some time behind other languages, that’s now fixed. +
- I reckon CL is still quite hard for the web, it doesn’t have a killer web framework (though maybe Weblocks, CLOG or ISSR soon©, all isomorphic web frameworks), hence no hype. +
- CL seems to be used for big, non-trivial projects, hence it gets no easy hype. +
- CL has no entity doing marketing today. We saw the Common Lisp +foundation pairing with sponsors recently. It did receive a lot of +financial and institutional support from the MIT, the NASA, Xerox, Carnegie +Mellon University (CMUCL), Lisp vendors (Symbolics, Lucid, Franz…),… +
- CL worked well with Emacs, Vim, CCL’s built-in editor on macOs, +LispWorks’ editor (which has a free version), but this doesn’t +satisfy the masses. We now have more options, including Atom (very +good support), VSCode (okay support) and Eclipse (basic support). +
- other reasons: it may be hard (or harder than the concurrence) to +grasp and getting started with, Lisp isn’t for everyone, it gets a lot of +FUD, and has a so-called Lisp curse! +
but that’s all debatable, I wouldn’t focus much on this. Times are +good for +implementations, that’s what counts.
+ +
+
+ Replic v0.12
+Lisp journey 29 10 2019
+We recently pushed our replic
+library version 0.12, adding a couple of expected features, thanks to
+the input of our users user:
-
+
- we can TAB-complete sentences (strings inside quotes) +
- we can define a different completion method for each arguments of a +command. +
- we added a declarative way to automatically print a function’s +result. The default function can be overriden by users (in order +too, for example, color output). +
So we can do something like this: we create a function (that will +become a command on the readline command line):
+ +(defun say (verb name)
+ (format t "~a, ~a !~&" verb name))
+We define how to TAB-complete its arguments:
+ +(replic.completion:add-completion "say"
+ (list "greetings" "\"nice to see you\"")
+ (lambda () *names*))
+Now if you type say TAB you get the two greeting choices. After you
+pick one and press TAB again, you get the names that were given to
+hello.
What’s beginning to be wanted now is fuzzy completion.
+ +Hope you enjoy.
+ ++ +
What is replic’s goal ?
+ +++ +Building a readline application is cool, but readline gives you the +basics and you must still build a REPL around it: loop and read +commands, catch a =C-c=, a =C-d=, ask confirmation to quit, print +the general help, the help of a command, setup the completion of +commands, the completion of their arguments, load an init file, +colorize output,… =replic= does this for you.
+
Replic’s goal is that when you have a lisp library, with lisp +functions, it should be straightforward to create a terminal +application out of it.
+ +Here’s an example in the wild. The lyrics library is cool. It is a lisp library, it must be used on the Lisp REPL. This is the amount of code that was needed to create a terminal application out of it: https://github.com/mihaiolteanu/lyrics/pull/1/files
+
+ Compile Time Type Checking in Common Lisp
+Lisp journey 29 10 2019
+We often hear that Common Lisp is dynamically typed, which is not +wrong, but that leads to the belief that Lisp is as bad as Python +concerning types, which is plainly wrong. We don’t hear enough that CL +is a compiled language, that we can add type annotations, and that +SBCL does thorough type checking. Hence, what we have at hand is +awesome: we can compile a whole program or compile a single function +and get type warnings. Once again, the feedback is immediate. We can +define our own types and get compile-time type warnings.
+ +You use a paramater that must be a list of list of strings of length 3 +? Ok, define the type:
+ +(defun list-of-3tuples-strings-p (list)
+ "Return t if LIST is a list composed of 3-tuples, made only of strings."
+ (and (consp list)
+ (every (lambda (it)
+ (and
+ (= 3 (length it))
+ (every #'stringp it)))
+ list)))
+
+(deftype alist-of-3tuples-strings ()
+ `(satisfies list-of-3tuples-strings-p))
+and type the variable as explained below.
+ +It’s useful for development, it’s also great to catch errors in a
+user’s configuration file. Checks are done when we load a file, and
+error messages are explicit. We use this now in the Next browser.
We don’t hear a lot about all that, maybe because the information was +hard to find, maybe because SBCL was not there at the time Lisp books +were written. The following was published to the Common Lisp +Cookbook /type.html, so +hopefully the issue is solved!
+ +On the topic, don’t miss these:
+ +-
+
- the article Static type checking in SBCL, by Martin Cracauer +
- the article Typed List, a Primer - let’s explore Lisp’s fine-grained type hierarchy! with a shallow comparison to Haskell. +
- the Coalton library +(pre-alpha): adding Hindley-Milner type checking to Common Lisp +which allows for gradual adoption, in the same way Typed Racket or +Hack allows for. It is as an embedded DSL in Lisp that resembles +Standard ML or OCaml, but lets you seamlessly interoperate with +non-statically-typed Lisp code (and vice versa). +
Compile-time type checking
+ +You may provide type information for variables, function arguments
+etc via the macros declare and declaim.
+However, similar to the :type slot
+introduced in CLOS section, the effects of type declarations are
+undefined in Lisp standard and are implementation specific. So there is no
+guarantee that the Lisp compiler will perform compile-time type checking.
However, it is possible, and SBCL is an implementation that does +thorough type checking.
+ +Let’s recall first that Lisp already warns about simple type +warnings. The following function wrongly wants to concatenate a string +and a number. When we compile it, we get a type warning.
+ +(defconstant +foo+ 3)
+(defun bar ()
+ (concatenate 'string "+" +foo+))
+; caught WARNING:
+; Constant 3 conflicts with its asserted type SEQUENCE.
+; See also:
+; The SBCL Manual, Node "Handling of Types"
+The example is simple, but it already shows a capacity some other +languages don’t have, and it is actually useful during development ;) +Now, we’ll do better.
+ +Declaring the type of variables
+ +Use the macro declaim.
Let’s declare that our global variable *name* is a string (you can
+type the following in any order in the REPL):
(declaim (type (string) *name*))
+(defparameter *name* "book")
+Now if we try to set it with a bad type, we get a simple-type-error:
(setf *name* :me)
+Value of :ME in (THE STRING :ME) is :ME, not a STRING.
+ [Condition of type SIMPLE-TYPE-ERROR]
+We can do the same with our custom types. Let’s quickly declare the type list-of-strings:
(defun list-of-strings-p (list)
+ "Return t if LIST is non nil and contains only strings."
+ (and (consp list)
+ (every #'stringp list)))
+
+(deftype list-of-strings ()
+ `(satisfies list-of-strings-p))
+Now let’s declare that our *all-names* variables is a list of strings:
(declaim (type (list-of-strings) *all-names*))
+(defparameter *all-names* "")
+We can compose types:
+ +(declaim (type (or null list-of-strings) *all-names*))
+Declaring the input and output types of functions
+ +We use again the declaim macro, with ftype (function …) instead of just type:
(declaim (ftype (function (fixnum) fixnum) add))
+;; ^^input ^^output [optional]
+(defun add (n)
+ (+ n 1))
+With this we get nice type warnings at compile time.
+ +If we change the function to erroneously return a string instead of a +fixnum, we get a warning:
+ +(defun add (n)
+ (format nil "~a" (+ n 1)))
+; caught WARNING:
+; Derived type of ((GET-OUTPUT-STREAM-STRING STREAM)) is
+; (VALUES SIMPLE-STRING &OPTIONAL),
+; conflicting with the declared function return type
+; (VALUES FIXNUM &REST T).
+If we use add inside another function, to a place that expects a
+string, we get a warning:
(defun bad-concat (n)
+ (concatenate 'string (add n)))
+; caught WARNING:
+; Derived type of (ADD N) is
+; (VALUES FIXNUM &REST T),
+; conflicting with its asserted type
+; SEQUENCE.
+If we use add inside another function, and that function declares
+its argument types which appear to be incompatible with those of
+add, we get a warning:
(declaim (ftype (function (string)) bad-arg))
+(defun bad-arg (n)
+ (add n))
+; caught WARNING:
+; Derived type of N is
+; (VALUES STRING &OPTIONAL),
+; conflicting with its asserted type
+; FIXNUM.
+This all happens indeed at compile time, either in the REPL,
+either with a simple C-c C-c in Slime, or when we load a file.
+ 
+
+
+ Cleanup
+MonkeyUser 29 10 2019
+
+
+ Things I wish someone had explained about functional programming
+James Sinclair 28 10 2019
+
+
+ Things I wish someone had explained about functional programming
+Web Development - James Sinclair 28 10 2019
+
+
+ September 2019 Monthly Update
+News on Clojurists Together 28 10 2019
+
+
+ Testing an API with emacs and restclient
+(ノ°Д°）ノ︵ ┻━┻ 27 10 2019
+
+
+ Testing an API with emacs and restclient
+(ノ°Д°）ノ︵ ┻━┻ 27 10 2019
++When we're developing some application we frequently interact with APIs.
++There are applications like postman, httpie, insomnia and so on to accomplish this task but having an external application only to test a few endpoints or even a complex API is a little overkill.
++Using emacs and a great package called restclient.el we can have a very complete tool to handle API requests without leaving our favorite editor.
+
+
++Installation +
+
+
++Put these lines of code in your emacs configuration and you'll be ready to go.
+
+
+
+(use-package restclient
+ :ensure t
+ :mode (("\\.http\\'" . restclient-mode)))
+Here we're using use-package to install restclient.el and also we're configuring restclient to use extension .http to enable its features.
+Now if we open a file with .http extension restclient will be enabled automatically.
+
++Example api +
+
+
++We'll be using a example API to test the features of restclient so I prepared a little API in flask with a few endpoints to allow us to check the features of restclient.
++This is the code of the application in case you are curious
+
+
+
+from uuid import uuid4
+
+from flask import Flask, escape, jsonify, make_response, request
+
+app = Flask(__name__)
+
+items = [{"uid": uuid4().hex, "name": f"item {i + 1}"} for i in range(3)]
+
+
+SECRET = "password"
+
+
+@app.route("/")
+def index():
+ name = request.args.get("name", "World")
+ return f"Hello, {escape(name)}!"
+
+
+@app.route("/api")
+def api():
+ return jsonify({"version": 1.0})
+
+
+@app.route("/api/items")
+def list_items():
+ return jsonify({"data": items})
+
+
+@app.route("/api/items", methods=["post"])
+def create_item():
+ if authenticated(request):
+ new_item = {"uid": uuid4().hex, "name": request.json.get("name")}
+ items.append(new_item)
+ return make_response(jsonify({"data": new_item}), 201)
+ else:
+ return make_response(jsonify({"error": "please provide credentiales"}), 401)
+
+
+def authenticated(req):
+ token = req.headers.get("authorization")
+ return token is not None and token == SECRET+If you don't want to install any other software to test this API you can use a docker image that contains this application.
+
+Just run the following command and you'll have an API running on port 5000.
+
+
+docker run -p 5000:5000 erickgnavar/restclient-api-example:0.1+Now we're ready to test out API using restclient.
+
+
++Usage +
+
+
+
+Let's see some examples of how can we use restclient from within emacs but first lets create a file called api.http and open it from emacs.
+
+Make a
+
+
+Make a GET request
+
+
+
+
+We can execute this code using C-c C-c to show the results in the current buffer or use C-c C-v to show them in a new buffer.
+
+GET http://localhost:5000/?name=guest
+Content-Type: application/json+Result:
+
+
+
+Hello, guest!
+<!-- GET http://localhost:5000/?name=guest -->
+<!-- HTTP/1.0 200 OK -->
+<!-- Content-Type: text/html; charset=utf-8 -->
+<!-- Content-Length: 13 -->
+<!-- Server: Werkzeug/0.16.0 Python/3.6.9 -->
+<!-- Date: Tue, 29 Oct 2019 05:34:44 GMT -->
+<!-- Request duration: 0.023261s -->+As we can see we can define a http request in plain text. We just need to define the method and the URL of our API. In this case we're querying the root of the API. Also the response is presented in plain text including some useful data like http headers and the request duration. We can define the http request headers as well.
+
+In this case the response use an html format as we can see in the Content-Type response header.
++Note: when you create a file with many requests in it make sure you split them using a comment
+#, for example:++++GET http://localhost:5000/?name=foo +# a split +GET http://localhost:5000/?name=bar +# a split +GET http://localhost:5000/?name=baz+If you don't add a separator an error will be raised when you try to execute the request.
+
+
++JSON responses +
+
+
++Now lets try to fetch a json type endpoint. Restclient identifies the content-type of the response and use an emacs mode that fits with the content-type. In this case the response is a json object so restclient enable js-mode to present the response.
+
+
+GET http://localhost:5000/api
+Content-Type: application/json+Result:
+
+
+
+{
+ "version": 1.0
+}
+// GET http://localhost:5000/api
+// HTTP/1.0 200 OK
+// Content-Type: application/json
+// Content-Length: 16
+// Server: Werkzeug/0.16.0 Python/3.6.9
+// Date: Tue, 29 Oct 2019 05:42:01 GMT
+// Request duration: 0.025286s
++Let's try with another endpoint that has more interesting information.
+
+
+GET http://localhost:5000/api/items
+Content-Type: application/json+Result:
+
+
+
+{
+ "data": [
+ {
+ "name": "item 1",
+ "uid": "931d90b493e944d9816061f46b57ce92"
+ },
+ {
+ "name": "item 2",
+ "uid": "edf9c8dda1ed4e8da205c53d9978ede2"
+ },
+ {
+ "name": "item 3",
+ "uid": "57a5146e3c98479785374f38e9e4c056"
+ }
+ ]
+}
+// GET http://localhost:5000/api/items
+// HTTP/1.0 200 OK
+// Content-Type: application/json
+// Content-Length: 188
+// Server: Werkzeug/0.16.0 Python/3.6.9
+// Date: Tue, 29 Oct 2019 05:42:33 GMT
+// Request duration: 0.026217s
+
+
++Variables and dynamic content +
+
+
+
+What happen if we need to pass some extra information to make an http request? In restclient we can have variables and we use them in the definition of the request. In this case we'll define a password variable which contains the required Authorization value to be able access to this endpoint. Also we can define the payload of the request, in this case a json object.
+First let's try a wrong password to see what happen.
+
+
+:password = wrong-password
+
+POST http://localhost:5000/api/items
+Content-Type: application/json
+Authorization: :password
+{
+ "name": "new item"
+}+Result:
+
+
+
+{
+ "error": "please provide credentiales"
+}
+// POST http://localhost:5000/api/items
+// HTTP/1.0 401 UNAUTHORIZED
+// Content-Type: application/json
+// Content-Length: 40
+// Server: Werkzeug/0.16.0 Python/3.6.9
+// Date: Tue, 29 Oct 2019 05:47:24 GMT
+// Request duration: 0.036553s
++We received a 401 response because the credentiales we used are not correct. Now let's try it again but now with the correct credentials.
+
+
+:password = password
+
+POST http://localhost:5000/api/items
+Content-Type: application/json
+Authorization: :password
+{
+ "name": "new item"
+}+Result:
+
+
+
+{
+ "data": {
+ "name": "new item",
+ "uid": "f1ede16e39754b3eb735627e78d26146"
+ }
+}
+// POST http://localhost:5000/api/items
+// HTTP/1.0 201 CREATED
+// Content-Type: application/json
+// Content-Length: 70
+// Server: Werkzeug/0.16.0 Python/3.6.9
+// Date: Tue, 29 Oct 2019 05:48:15 GMT
+// Request duration: 0.034962s
++As we can see the request was made successfully. Variables in restclient are evaluated at the time the request is made so we can define a variable and use it in as many requests as we want. This is useful when we're working with APIs that need some authentication to allow us to access to their endpoints. We can request a token then save it and use it for the rest of the request we've defined in our file.
+
+
++Other useful features +
+
+
+
+
++Convert request to curl format +
+
+
+
+If we need to pass a request with its data to some friend who doesn't use emacs we can pass the request definition(it's just plain text after all) but we can also generate a curl command so it's going to be easy for anyone to test the request.
+We can use C-c C-u from within out request to generate a curl command. After we execute this keybinding the curl command will be copied to the clipboard.
+If we use this in our previous example we'll get the following curl command:
+
+
+ curl -i -H Authorization\:\ password -H Content-Type\:\ application/json -XPOST http\://localhost\:5000/api/items -d \{'
+ '\ \ \ \ \"name\"\:\ \"new\ item\"'
+ '\}+Now we can paste this in a terminal and the request will be made.
+
+
++Navigate through the available requests +
+
+
+
+From the same author we have restclient-helm this package allow us to jump easily to a specific request using the combination C-c C-g. This is useful if we are working with an extensive API and we want to find some request quickly.
+This package use helm to present the available options and when we chose one the cursor will jump to the selection.
+
++Formatting payload +
+
+
+
+If we are using json as the request body we'll need to have it formatted in some way. We can use json-mode for accomplish this.
+Now our installation code will be:
+
+
+
+(use-package json-mode
+ :ensure t)
+
+(use-package restclient
+ :ensure t
+ :defer t
+ :mode (("\\.http\\'" . restclient-mode))
+ :bind (:map restclient-mode-map
+ ("C-c C-f" . json-mode-beautify)))
+We're adding a new keybinding to restclient-mode-map so we can use C-c C-f to format the request body.
+
+
+ +Conclusion +
+
+
+
+Having our requests defined in plain text allow us to use it even as documentation and we don't depend of some external app that use a custom format to store these requests. We can freely pass this .http file to anyone and they will be able to read it and understanding it without the need to install an application.
+
+ Q4 2019 Survey Results and Call for Proposals
+News on Clojurists Together 22 10 2019
+
+ 
+
+
+ Everyday Excuses
+MonkeyUser 22 10 2019
+
+
+ Minimal Setup for Elixir development in Emacs
+(ノ°Д°）ノ︵ ┻━┻ 19 10 2019
+
+
+ Minimal Setup for Elixir development in Emacs
+(ノ°Д°）ノ︵ ┻━┻ 19 10 2019
++I've been working professionally with Elixir for 7 months, obviously using emacs as my daily editor. In this post we'll see some packages that could be useful for Elixir development.
++I'm not using LSP (yet), so the goal here is just to have a minimal setup for Elixir development.
+
+We're going to use use-package to install all the needed packages.
+
++Syntax highlighting +
+
+
+
+We'll use Elixir-mode. This package give us syntax highlighting support and some useful features like mix-format which let us format our code using mix format task, which is available since Elixir 1.6
+
+
+(use-package elixir-mode
+ :ensure t
+ :bind (:map elixir-mode-map
+ ("C-c C-f" . elixir-format)))
+
++Go to definition +
+
+
+
+A LSP backed package like elixir-lsp could be way more accurate for this functionality but now we're going to use dumb-jump.
+This package give us "go to definition" functionality just using regex. It has support for Elixir out the box and it works pretty well.
+
+We'll use helm to show the different options when dumb-jump finds more than one definition for the same term.
+
+
+(use-package dumb-jump
+ :ensure t
+ :init
+ (setq dumb-jump-selector 'helm))
+
++Snippets +
+
+
++Using snippets can improve the speed of writing code. I'm using yasnippet, a snippets template system, and also a set of snippets(for many languages including Elixir) called yasnippet-snippets.
+
+We can install these packages with the following code. Notice that we're enabling yasnippet only for a few modes. If you want to you can enable it globally using (yas-global-mode 1).
+
+
+(use-package yasnippet
+ :ensure t
+ :hook ((prog-mode . yas-minor-mode)
+ (conf-mode . yas-minor-mode)
+ (text-mode . yas-minor-mode)
+ (snippet-mode . yas-minor-mode)))
+
+(use-package yasnippet-snippets
+ :ensure t
+ :after (yasnippet))
+
++Running tests +
+
+
++Running tests without leaving our editor is a nice feature to have in any editor/IDE. Unfortunately I haven't found any package that does this, so I wrote some elisp code to accomplish it.
+
+To make this happen we're going to use feature called compile. Compile allows us to execute a shell command and print the resulting output in a "compilation" buffer so we can see the results.
+We can run tests using mix test in different ways
-
+
-
+
+mix test: run all the tests within our project.
+ -
+
+mix test path_to_test_file.exs: run the given test file.
+ -
+
+mix test path_to_test_file.exs:line_number: run the test defined around the given line number.
+
There are some other ways but these are the ones we're going to use.
+
+
+
+(defun my/mix-run-test (&optional at-point)
+ "If AT-POINT is true it will pass the line number to mix test."
+ (interactive)
+ (let* ((current-file (buffer-file-name))
+ (current-line (line-number-at-pos))
+ (mix-file (concat (projectile-project-root) "mix.exs"))
+ (default-directory (file-name-directory mix-file))
+ (mix-env (concat "MIX_ENV=test ")))
+
+ (if at-point
+ (compile (format "%s mix test %s:%s" mix-env current-file current-line))
+ (compile (format "%s mix test %s" mix-env current-file)))))
+
+(defun my/mix-run-test-file ()
+ "Run mix test over the current file."
+ (interactive)
+ (my/mix-run-test nil))
+
+(defun my/mix-run-test-at-point ()
+ "Run mix test at point."
+ (interactive)
+ (my/mix-run-test t))
+We have three functions, a "private" function called my/mix-run-test which will do all the "magic", this function will get some data about the context where it was called.
+We got the current-file and current-line from where the function was called, and now we'll use this to build our shell command and then use this shell command to call compile.
+Now we can create two more functions to expose two different behaviors, running an entire test file or just the test our cursor is placed on. +We're going to use the latest to have a keybinding a run the test quickest.
++Now we can add this to our previous code:
+
+
+
+(use-package elixir-mode
+ :ensure t
+ :bind (:map elixir-mode-map
+ ("C-c C-f" . elixir-format)
+ ("C-c C-t" . my/mix-run-test-at-point)))
+Now if we press C-c C-t in a file(my_test.exs) where our cursor is on line 10, emacs will build the command mix test my_test.exs:10 and run it in a compilation buffer.
+
++Others useful packages +
+
+
+-
+
-
+
Projectile: It's a package to handle many projects. It allows us to switch between projects easily.
+
+ -
+
Magit: The best interface so far for use git. If you haven't use it you definitively should give it a try.
+
+ -
+
direnv-mode: It's a package to load environment variables using a
+.envrcfile. It's useful to load all the environment variables you need for a project.
+
+
+
+ +Conclusion +
+
+
++I use this setup with a few tweaks in my daily work and it works pretty well for my needs.
+
+ 
+
+
+ Expert Software Designers, V8, Web Page Test, Lovestruck with React, for..in, git, and roughViz! 🧠 — Pony Foo Weekly
+Pony Foo Weekly 17 10 2019
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
Expert Advice
|
|
|
|
A Mixed Bag
|
Code Things
|
|
+ 
+
+
+ Edge Cases
+MonkeyUser 15 10 2019
+
+ 
+
+
+ VR, Intercepting HTTP, QUIC & HTTP/3, Performance, Intersection Observer, Async Functions, Recursion in React! 🍨 — Pony Foo Weekly
+Pony Foo Weekly 10 10 2019
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
Bleeding Edge
|
|
|
|
|
Web of Bits
|
|
|
|
Just React Things
|
|
|
|
+
+ ¿Compostamos? Compostaje y el quinto contenedor
+Andanzas de una ambientóloga . . . 09 10 2019
+
+ 
+
+
+ 10 principios básicos de diseño
+Blog de Diseño Web Vida MRR 08 10 2019
+ |
Hace tiempo que no hablamos de diseño. En este post les voy a platicar sobre 10 principios básicos que todo diseño debe tener, independientemente de donde lo veamos, creemos o imprimamos, estos 10 principios deben estar siempre visibles y saber representarse en una obra como dibujo, interfaz web, diseño web, etc. Así que comencemos 👍🏼
1. Balance
El balance se entiende como la armonía de elementos, tanto gráficos como de fuentes, colores, ilustraciones, etc. Incluso un diseño super saturado puede tener balance. Incluso el diseño más minimalista y sobrio puede tener balance, y eso depende de qué tan bien acomodamos los elementos, para que exista armonía y estructura.No significa que todos los elementos deban estar alineados o milimétricamente separados por la misma distancia, sino que a simple vista no piensen que a un diseño le faltó color, o algún elemento para rellenar, o que hay un espacio de más que no encaja.
2. Proximidad
La proximidad ayuda a crear relación entre elementos de un diseño. No se vería bien tener un campo de búsqueda en un extremo de la pantalla y el botón para buscar al otro lado, porque no tendrían proximidad.Ese ejemplo básico sirve para ejemplificar que los elementos en un diseño deben estar juntos y separados dependiendo del significado y la intención que queremos dar. Ni todo super junto, ni todo separado si no existe un significado que explique por qué tiene que ser así.
3. Alineación
Muchos diseñadores que empiezan creen que por alineación tiene que ser todo al centro o distribuido, como si pusieras tus elementos en una caja donde no pueden salir, y no hay nada más erróneo que eso. Alineación significa orden y se combina con proximidad. Hay elementos que en conjunto dan un significado y necesitan una alineación, y hay otros que no.Un ejemplo de esto es cuando en una aplicación tenemos un menú lateral. Los elementos que están relacionados estarán alineados y agrupados; aquellos que no tendrán otra alineación, posición y distribución, y no necesariamente tienen que estar desalineados.
4. Jerarquía visual
Este es uno de los elementos más importantes, ya que permite a los usuarios dirigir la mirada en lo más importante primero, y en lo secundario al final. La jerarquía implica que usen fuentes más grandes en los textos que quieres resaltar, imágenes más llamativas en donde la imagen es la principal, y todos los demás elementos como secundarios, pequeños, no tan llamativos y que aún así complemente tu diseño.5. Repetición
¿Alguna vez han visto que empiezan a definir estilos CSS para ciertos campos y al final terminando aplicando otros? este es un problema de repetición, ya que sin un estilo de colores a lo largo de un proyecto se pierde el sentido de marca.Usar la misma paleta de colores en todo el diseño, o en un sitio web es primordial para mantener consistencia, de tal forma que ese botón azul con borde redondeado lo identifiques en todas las páginas de tu sitio, y no te confundas con otro que tiene otra forma y color.
6. Contraste
Hemos hablado mucho del contraste en el blog. Sin contraste no sabríamos diferenciar elementos del fondo, texto como cabecera de texto de párrafo, o de ilustraciones entre sí. Siempre recuerda tener contraste, no solo a nivel de blanco-negro, sino de diferentes colores, formas y fuentes que permita que no exista un resalte, una duda o una interpretación que implique gastar la vista.7. Color
En colores hay toda una ciencia de cómo escoger una gama de colores. No es tema de este post pero los puntos importantes son:- no uses más de dos o tres colores para un diseño
- usa tonos de grises
- usa una paleta de colores usando alguna aplicación de combinación de colores
- trata de ver combinaciones nuevas, no uses siempre las mismas
8. Espacio negativo
El espacio negativo se usa cuando jugamos con las siluetas de otros elementos para crear más elementos. No es un recurso que deberíamos explotar demasiado pero sí lo suficiente para que el usuario se sorprenda al identificar por sí mismo la figura escondida9. Tipografía
La tipografía es super importante para cada diseño, y por lo tanto necesita una tipografía específica para ello. Evitemos usar las que vienen por defecto en nuestra computadora. Las fuentes que puedes encontrar en internet de forma gratuita son ideales para crear textos llamativos pero no muy originales, y las que tienes que pagar son las que son perfectas para crear toda una colección e identidad para el diseño.10. Estilo propio
Ya que conoces todos estos principios, entonces ya puedes buscar tu propio estilo, combinando, creando y ajustando todos los principios anteriores a algo que siga manteniendo un diseño bueno. El estilo propio es lo que eventualmente muchos lanzan como lenguaje de diseño, estilos, temas, y todo lo que puedas relacionar a nivel de diseño para un sitio, aplicación, campaña de publicidad, y muchas cosas más.
+ 
+
+ 
+
+
+ S3cur1ty
+MonkeyUser 08 10 2019
+
+ 
+
+
+ Instapaper Save now available for Safari on Mac
+Instapaper 02 10 2019
+Today we’re launching Instapaper Save for Safari on Mac. You can download it now from the Mac App Store.
Once you’ve downloaded the app, you can set up the Safari extension as follows:
- Open the app
- Login with your account
- After you’re logged in, click “Open Safari Preferences”
- Enable “Instapaper 1.0” in the Extensions tab of Safari Preferences
In order to make the updated Safari extension available as soon as possible, this version of the extension only supports saving by clicking the Instapaper toolbar icon in Safari. In future versions we plan to add:
- Inline Twitter link saving.
- Right-click to save links or pages.
- Keyboard shortcut to save.
- An extension to save links from other macOS apps.
If you have any questions, feature requests, or issues you’d like us to sort out, please let us know at support@instapaper.com or @InstapaperHelp on Twitter. Thanks for using Instapaper!
+
+ 
+
+
+ Product Description
+MonkeyUser 01 10 2019
+
+
+ Preventing SQL Injection Attacks With Python
+Haki Benita 30 09 2019
+SQL injection attacks are constantly ranked among the most common attacks against systems. While binding values is very common, I often find my self needing to being table and column names as well. This article will walk you through everything you need to know about SQL injections in Python.
+
+ 
+
+
+ Hyperreals *R: Manejo de rutas con pathlib
+Python Hispano 28 09 2019
+Es difícil escribir un script de python que no interaccione con el sistema de ficheros de un modo u otro, por lo que python dispone de varios módulos para tal fin: os, os.path (submódulo de os), shutil, stats, glob,…En la intención estaba ser multiplataforma, lo que ha sido fuente de muchos mayores quebraderos de cabeza con las distintas codificaciones de caracteres y distintas formas de expresar rutas de ficheros que existen.
El objeto Path viene a poner orden entre tantos módulos y funciones para manejo de ficheros. La librería estándar se ha reescrito para aceptar estos objetos Path. Se puede decir sin duda que usar Path se ha convertido en la forma más pythónica de manipular ficheros y directorios.
Empecemos por un ejemplo traído de la documentación oficial:
+>>> from pathlib import Path
+>>> p = Path('/etc')
+>>> q = p / 'init.d' / 'reboot'
+>>> q
+PosixPath('/etc/init.d/reboot')
+>>> q.resolve()
+PosixPath('/etc/rc.d/init.d/halt')
+Paso por paso: importa el constructor Path del módulo pathlib. Con él construye un objeto con la ruta /etc y, usando el operador /, genera otro objeto que representa la ruta /etc/init.d/reboot. Automáticamente, estos objetos se construyen como instancias de PosixPath, que es una subclase especializada de Path para manejos de ficheros en sistemas Posix. La ruta /etc/init.d/reboot apunta a un enlace simbólico, por lo que se usa el método resolve para obtener la ruta absoluta del fichero al que apunta.
+
+Nota
+Observa que las operaciones con objetos Path generan objetos Path con lo que podemos encadenar operaciones para navegar a través de una jerarquía de directorios.
+Módulos a los que sustituye o no sustituye
+Obviamtente, el módulo clásico os.path, utilizado para manipulación de rutas, es reemplazado totalmente por pathlib.
Del módulo os reemplaza muchas de sus funciones para manipular ficheros y directorios. Aún así, el módulo os contiene otras muchas funciones para el manejo de entornos o lanzamiento de procesos que no cambian. Así mismo, hay algunas operaciones especializadas con ficheros y directorios (eg: os.walk) que no han sido reempladas. De hecho son más eficientes que si se hicieran con objetos Path.
Otro módulo que ya no es necesario es glob, utilizado para buscar ficheros mediante patrones de búsqueda.
Rutas puras y concretas
+Según si tienen acceso al sistema de ficheros, podemos distingure entre:
+-
+
- Ruta pura: rutas que no requieren acceso al sistema de ficheros (
PurePath,PurePosixPath,PureWindowsPath)
+ - Ruta concreta: rutas con acceso al sistema de ficheros (
Path,PosixPath,WindowsPath)
+
Las rutas puras son superclases de las rutas concretas. Mejor verlo gráficamente como jerarquía de clases:
+
Ejemplos
+Voy a poner algunos ejemplos de uso de pathlib para que compares con el modo como lo estabas haciendo hasta ahora. Recomiendo revisar la documentación del módulo pathlib ante cualquier duda.
Para escribir en un fichero, usamos el método open de modo similar a como se hacía con la función open del mismo nombre:
from pathlib import Path
+
+path = Path('.config')
+with path.open(mode='w') as config:
+ config.write('# config goes here')
+Si sólo vamos a escribir una línea, también se podría hacer de un modo más directo:
+Path('.config').write_text('# config goes here')
+Pongamos un ejemplo más complejo: queremos localizar los scripts de python dentro de la carpeta proyectos que tengan una frase. Lo habitual para recorrer un directorio era usar alguna función como os.walk o os.scandir para ir navegando a través de la jerarquía de directorios e ir leyendo los ficheros python hasta localizar los que buscamos.
Veamos cómo se hace con Path:
from pathlib import Path
+
+proyectos = Path.home() / 'proyectos' # carpeta en el directorio HOME
+palabra = "pathlib"
+
+ficheros = [p for p in proyectos.rglob("*.py")
+ if palabra in p.read_text()]
+Partimos del Path.home(), el directorio de usuario, y creamos la ruta del directorio proyectos. Invocando el método .rglob() obtenemos, recursivamente, todos los ficheros que cumplan con el patrón dado. Bastante simple.
La lista resultante es una lista de objetos Path, lo que nos facilita cualquier manipulación posterior que deseemos hacer sobre estos ficheros. Por ejemplo, vamos a calcular el tamaño total que ocupan:
+size = sum(p.stat().st_size for p ficheros)
+Si se prefiere, se puede seguir usando el viejo os.path.getsize. Ahora también acepta objetos Path:
import os.path
+
+size = sum(os.path.getsize(p) for p ficheros)
+
+ 
+
+
+ Instapaper iOS 7.8: Dark Mode, Improved Scroll Performance, and “Share Image”
+Instapaper 26 09 2019
+
Today we launched Instapaper 7.8 for iOS 13. In the new version, dark mode will automatically turn on when you enable dark mode at the system level through iOS Settings > Display & Brightness > Dark mode. Disabling dark mode will return Instapaper to your non-dark mode theme. If you set your device to automatically go into dark mode, Instapaper will mirror the transition.
+Additionally, we rewrote the article list to improve scroll performance, especially during large volume syncs. You should now see smoother scrolling in general, and especially while content is downloading.
+Lastly, we’ve expanded the “Tweet Shot” feature to be compatible with apps beyond Twitter. With the new “Share Image” option, you can now share an image of your highlight or text selection to any app (including Twitter, of course).
+
If you have any questions, feature requests, or issues you’d like us to sort out, please let us know at support@instapaper.com or @InstapaperHelp on Twitter. We love hearing from you and we thank you for using Instapaper!
+
+ 
+
+
+ Performance budgets, Preloading, Profiling Performance and Animations, Visual Regression Testing & Tensorflow! 🎪 — Pony Foo Weekly
+Pony Foo Weekly 26 09 2019
+We’re glad you could make it this week!
With your help, we can make Pony Foo Weekly even more awesome: send tips about cool resources.
Raw Performance
|
|
|
Perf Profiling
|
|
|
|
|
Even more stuff
|
|
+ 
+
+
+ v2.0.1
+MonkeyUser 24 09 2019
+
+
+ Reddit: ABCL Common Lisp vs Clojure
+Lisp journey 22 09 2019
+Not that I’m interested in using the Java platform :D but relevant +comparisons between ABCL (Common Lisp on Java) and Clojure are +rare. We just had a nice feedback on reddit, so here it is. The +question was:
+ +++ +After looking at the quite old benchmarks, ABCL seems to perform alright. Can anyone share their experience with ABCL in terms of performance, stability and memory usage?
+
+ +
I wish I could give you more concrete numbers with an application you could test and see for yourself. Since I can’t do that, I will tell you about my recent work with ABCL. I ported a small Clojure server-side utility to ABCL and can qualitatively tell you that the performance was close to Clojure. After profiling the ABCL version, I believe I can attribute the differences to ABCL’s use of Java reflection for its Java FFI.
+ +I’ve already been successfully deploying Clojure-based applications professionally, and as I’ve gotten more into Common Lisp, I’d like to start deploying Common Lisp based applications as well. I recently posted a patch to the ABCL mailing list and got a very quick response from the maintainer. I really like the quality of the ABCL code base. The compiler itself was very approachable and easy to understand.
+ +I think ABCL really is a worthwhile target in the Common Lisp world because:
+ +-
+
- Painless Java FFI. You avoid all the instability and signaling issues that crop up when using the JVM combined with SBCL or CCL. If you make a lot of calls, native Java is always going to be faster anyhow than calls over JNI (which is more comparable to reflection). +
- Use large heaps without worry. Part of the benefit of the JVM is its proven ability to have huge heaps (I’ve been part of projects that had 64GB+ heaps (though honestly I’d rather stay small)). +
- JVM platform is well supported and tested on a number of OS and hardware platforms +
SBCL uses conservative garbage collection and I’m curious how well it would handle really large heaps. CCL uses precise garbage collection but again, I’d like to know how it handles really large heaps. In general, I want all my applications to run with heaps that are naturally in CCL’s or SBCL’s sweet spot, but I’d love to know I could use ABCL if I really ever needed huge heaps. I’m really getting into Common Lisp because I really like the implementation choices. Having a solid Java FFI unfortunately is usually a requirement in my workplace.
+ +To me, ABCL will be /better/ than using Clojure if ABCL’s Java FFI moves away from reflection (when possible). This will close any performance gap with Clojure for most applications. I think this can be done relatively easily in the current ABCL implementation, and I have an idea of how to do it but unfortunately have had no time lately to devote to it. The reason I say “better than Clojure” is that I can write applications that target both ABCL and SBCL/CCL – I can abstract away my Java APIs if I really have to have them (or use LispWorks with a solid Java FFI if I don’t need a ton of Java interoperability). Then when I need fast startup time or low memory footprint, I can use these other CL implementations which are much better suited to it.
+ +The main benefit where I still see Clojure having an edge is if you need a heavy JS-based web interface. I’m not a JS developer, but I was able to successfully use Clojurescript and make a nice looking web application that had pretty seamless interoperability with my Clojure-based server.
+ +Anyhow, I hope this helps you. ABCL is great, I have been very impressed with it and I encourage you to try it out.
+ ++ +
by the user somewhat-functional on reddit, september 2019
+ 
+
+
+ Tribalism
+MonkeyUser 17 09 2019
+
+
+ How "Export to Excel" Almost Killed Our System
+Haki Benita 16 09 2019
+Inspired by an actual incident we had in one of our systems caused by an "Export to Excel" functionality implemented in Python, we go through the process of identifying the problem, experimenting and benchmarking different solutions.
+
+ 
+
+
+ Consejos para ser un mejor desarrollador
+Blog de Diseño Web Vida MRR 16 09 2019
+
Cuando se trata de programación no hay una forma o estándar a seguir para poder desarrollarse y madurar. Solo la experiencia te da más herramientas dentro de este mundo de programación, pero también hay actividades que puedes realizar para poder ir ganando más experiencia y seguir mejorando como desarrollador, y en este post te los voy a compartir.
Experimentar en varios proyectos
Puede sonar lógico que para poder ser un mejor desarrollador lo primero que tienes que ahcer s practicar, desarrollar proyectos, estar involucrado en varios, de tal forma que en cada uno aprendas algo diferente. Sin embargo aquí hay algunos puntos que deberías estar teniendo en cuenta al momento de tener proyectos para poder ser un mejor desarrollador
- Tienes que fallar para aprender: el terminar un proyecto sencillo no te da ningún aprendizaje. Aprende con el error y sabiendo tus capacidades técnicas
- Aprender significa tener creatividad: programar de la misma forma y haciendo las mismas aplicaciones no te dejan ninguna experiencia. Juega a hacer las cosas de diferentes formas para saber si lo que actualmente haces es la forma más adecuada o hay alguna mejor.
- Aplica los métodos paso a paso: ¿cuándo fue la última vez que seguiste todo un ciclo de desarrollo para una aplicación? cosas tan sencillas como esas las obviamos y nos vamos directo a programar y ver en el camino qué nos falta. Intenta ir lento, siguiendo la teoría, y verás que de la misma forma que buscas soluciones a tu código, vas a querer soluciones a situiaciones en las etapas.
Planea antes de programar
Como lo mencionaba anteriormente, solemos emepezar a programar sin siqueira estar seguros de lo que queremos lograr. La planeación es una etapa en la que tienes que poner bien los alcances de lo que vas a hacer, y el resultado que quieres obtener. Si solo empiezas a programar no vas a saber cuándo terminar, o al final no vas a recordar por qué empezaste ese prioyecto.
Sé duro con tu código
La mejor forma para mejorar como programador o desarrollador es siempre ser auto críticos con nuestro código. Si le presentaras tu código a algún desarrollador experto o con muchos años de experiencia, reconocido entre una comunidad ¿qué crees que diría de él? ¿qué es código de calidad? ¿o que es código de principiantes?
Siempre debemos buscar los patrones o mejores prácticas para nuestro código. Hay muchas metodologías y dependiendo del lenguaje irás aprendiendo si la técnica de programación que tienes es buena o mala, y a partir de ahí ver cómo la puedes mejorar.
Lee código de desarrolladores respetados
Es un punto adicional a lo que comentaba anteriormente. No hay nada mejor que ponerte al tú por tú contra un desarrollador que sea realmente bueno. Basta incluso con ver las librerías de organizaciones o comunidades Open Source y ver si entendemos el código que muestran, y después, validar si nuestro código es de la misma calidad.
En Github puedes encontrar desarrolladores que postean sus proyectos personales o de colaboración con otros, y medirte para ver qué tan bueno eres comparado con ellos.
Aprende a 'debuggear' código que no es tuyo
Si trabajas para una empresa que desarrolla proyectos a clientes esta es una de las situaciones más comunes que vas a vivir, y es la de heredar proyectos que alguien más hizo. Los más novatos dirán que ahorras tiempo si vuelves a hacer todo desde cero, pero lo cierto es que es al revés. Aprender a leer, debuggear y probar código de alguien más es una de las mejores experiencias (dolorosas, lo sé) que te puede ayudar para ser un mejor desarrollador, porque ahí pones en práctica qué tan bien lo harías tu, o qué tan mal dejaron ese código heredado.
Siempre trata de romper tu código
Los que empezamos a programar nos preocupamos más porque nuestro código funcione en el escenario ideal, a probar los escenarios donde no. Un código de calidad no es el que cumple su funcionamiento, sino que también responde ante entradas de datos erróneas, ante desbordamientos, ante escenarios extremos o nulos de datos, etc.
Conclusiones
Estos son algunos tips que puedes poner en práctica en tu día a día sin tener que invertir tiempo en cosas que no sean tareas comunes de cualquier desarrollador, solo necesitas la actitud y disposición para poder ejercerlas.
+ 
+
+ 
+
+
+ Tutorial conexión de MongoDB en Docker con Express y NodeJS
+Blog de Diseño Web Vida MRR 11 09 2019
+
He estado jugando con Docker para crear algunos servicios, y sobre todo, evitar tener que descargar e instalar plataformas que solo quiero usar de prueba. En mi último demo estuve jugando con MongoDB y se me ocurrió hacer un tutorial para enseñarles a configurar MondoDB en Docker para crear una conexión con NodeJS y ExpressJS.
Prerequisitos
Para poder seguir este tutorial se necesitan tener bases de cómo funciona NodeJS y ExpressJS, así como algo muy introductorio a Docker y Dockerfile, pero ya lo iré explicando.1. Creación de Dockerfile
Una de las maravillas que ofrece Docker es la posibilidad de preparar todos los componentes que necesitas para tu desarrollo en un editor de texto y de ahí ejecutarlo. Yo para poder montar MongoDB voy a necesitar dos servicios:- El motor de bases de datos de MongoDB
- Una interfaz web para administrar visualmente mis bases de datos. En este caso uso Mongo Express
version: '3.1'
services:
mongo:
image: mongo
container_name: mongodb
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: root
MONGO_INITDB_ROOT_PASSWORD: example
MONGO_INITDB_DATABASE: ejemplodb
ports:
- 27017:27017
mongo-express:
image: mongo-express
restart: always
container_name: mongodb-ui
ports:
- 8081:8081
environment:
ME_CONFIG_MONGODB_ADMINUSERNAME: root
ME_CONFIG_MONGODB_ADMINPASSWORD: example
Una vez hecho eso procedemos a correr el comando
docker-compose up
2. Configurar aplicación de NodeJS y ExpressJS
Ahora vamos a crear nuestra conexión desde nuestra aplicación de NodeJS usando Express. Lo primero es installar Expressnpm install express
npm install mongoose
const express = require('express');
const bodyParser = require('body-parser');
const cors = require('cors');
const mongoose = require('mongoose');
const PORT = 3000;
const app = express();
app.use(cors());
app.use(bodyParser.json());
app.get('/', (req, res) =>{
res.send('Index');
});
app.listen(PORT, () =>{
console.log('Servidor backend listo...');
});
- Incluir los módulos que vamos a ocupar
- Inicializar nuestro middleware, el cual puedes o no ocupar para tu aplicación
- inicializar un ruteo para cargar nuestro index
- configurar el puerto para escuchar peticiones
3. Conexión a MongoDB
Vamos a empezar con la conexión a nuestra base de datos:mongoose.connect('mongodb://localhost/basededatos', {useNewUrlParser: true, useUnifiedTopology: true});
const connection = mongoose.connection;
connection.once('open', () =>{
console.log('Conectado a la BD');
});
Algunos errores comunes
Al menos a mi en un principio traté de usar la conexión de este formamongoose.connect('mongodb://user:pass@localhost/db', {useNewUrlParser: true, useUnifiedTopology: true});
UnhandledPromiseRejectionWarning: MongoError: Authentication failed
Para ello nos conectamos a nuestra consola de mongo en Docker
docker exec -it mongodb mongo -u root
Ya dentro de nuestra consola de Mongo, vamos a ir a ejecutar la siguiente función para crear un nuevo usuario
use tu-base-de-datos
db.createUser({
user: 'user',
pwd: 'pass',
roles: [
{ role: 'readWrite', db: 'tu-base-de-datos' }
]
})
mongoose.connect('mongodb://user:pass@localhost/db', {useNewUrlParser: true, useUnifiedTopology: true});
+ 
+
+ 
+
+
+ Determinism
+MonkeyUser 10 09 2019
+
+
+ August 2019 Monthly Update
+News on Clojurists Together 09 09 2019
+
+ 
+
+
+ Introducción a promesas en Javascript
+Blog de Diseño Web Vida MRR 02 09 2019
+
Hoy en día manejar promesas es una de las actividades que necesitas hacer para poder programar aplicaciones mucho más robustas y limpias visualmente. En este tutorial vamos a ver una introducción a las promesas, para qué sirven y cómo nos ayudan en nuestro día a día como programadores.
¿Qué son las promesas?
Las promesas son una forma de poder implementar código, el cual se ejecute después de evaluar si una condición esperada es verdadera o salió algo mal. Muchas de las operaciones donde vamos a implementar promesas es en operaciones asíncronas, donde no sabemos cuando va a terminar una actividad, y por eso las promesas nos ayudan a evaluar si dicha operación asíncrona fue exitosa o falló.¿Cómo se implementan?
En Javascript vamos a usar la siguiente notación para crear una nueva promesa:Al definir una promesa debemos tomar en cuenta los dos parámetros que aparecen ahí, ya que son los que vamos a usar posteriormente en la implementación para mandar a llamarlos. Esos dos parámetros actúan como placeholders que van a invocarse cuando nosotros programemos que nuestra promesa tuvo éxito al ejecutar su actividad, o cuando hubo algún error.
Para un ejemplo muy sencillo podemos evaluar el valor de una variable. Si la variable cumple nuestra condición vamos a invocar a resolve() como función. Dentro de ella podemos colocar valores que queramos pasar para cuando se invoque nuestra promesa.
Por último, para mandar a llamar a nuestra promesa basta con ejecutar el método .then(), una vez hecho esto dentro podemos hacer referencia al valor que pasamos en la función de resolve() y con ello implementar una función. Si llegase a fallar nuestra promesa podemos usar el método .catch() para poder implementar una función de error
Al final, nuestro código completo se vería así:
Conclusiones
Las promesas en su mínima expresión son una forma muy poderosa de sustitución a los callbacks, además de que nos permiten definir la promesa y luego implementarla de forma muy ordenada sintácticamente. Más adelante vamos a ver otros usos más completos y avanzados ya poniendo en práctica otros temas de Javascript
+ 
+
+ 
+
+
+ Gut Feeling
+MonkeyUser 02 09 2019
+
+ 
+
+
+ Applied Scrum
+MonkeyUser 27 08 2019
+
+
+ Slime Tips
+Lisp journey 26 08 2019
+Recently on reddit there was a reminder about +lisptips.com and +slime-tips. I already knew the two, +but this time I fully enjoyed the Slime tips. I copy my favourites.
+ +As usual, I enhanced the Cookbook/emacs-ide.html at the same time.
+ +The Slime documentation is here: https://common-lisp.net/project/slime/doc/html/
+ +Documentation lookup
+ +-
+
- C-c C-d h looks up documentation in CLHS. But it works only on symbols, so there are two more bindings: +
- C-c C-d # for reader macros +
- C-c C-d ~ for format directives +
Other bindings which may be useful:
+ +-
+
- C-c C-d d describes a symbol using
describe
+ - C-c C-d f describes a function using
describe
+
Synchronizing packages
+ +C-c ~ (slime-sync-package-and-default-directory): When run in a +buffer with a lisp file it will change the current package of the REPL +to the package of that file and also set the current directory of the REPL +to the parent directory of the file.
+ +Calling code
+ +C-c C-y (slime-call-defun): When the point is inside a defun and +C-c C-y is pressed,
+ +(I’ll use [] as an indication where the cursor is)
+ +(defun foo ()
+ nil[])
+then (foo []) will be inserted into the REPL, so that you can write
+additional arguments and run it.
If foo was in a different package than the package of the REPL,
+(package:foo ) or (package::foo ) will be inserted.
This feature is very useful for testing a function you just wrote.
+ +That works not only for defun, but also for defgeneric, defmethod, +defmacro, and define-compiler-macro in the same fashion as for defun.
+ +For defvar, defparameter, defconstant: [] *foo* will be inserted
+(the cursor is positioned before the symbol so that you can easily
+wrap it into a function call).
For defclass: (make-instance ‘class-name ).
Inserting calls to frames in the debugger
+ +C-y in SLDB on a frame will insert a call to that frame into the REPL, e.g.,
+ +(/ 0) =>
+…
+1: (CCL::INTEGER-/-INTEGER 1 0)
+…
+C-y will insert (CCL::INTEGER-/-INTEGER 1 0).
(thanks to Slime tips)
+ +Exporting symbols
+ +C-c x (slime-export-symbol-at-point) from the slime-package-fu
+contrib: takes the symbol at point and modifies the :export clause of
+the corresponding defpackage form. It also exports the symbol. When
+called with a negative argument (C-u C-c x) it will remove the symbol
+from :export and unexport it.
M-x slime-export-class does the same but with symbols defined +by a structure or a class, like accesors, constructors, and so on. +It works on structures only on SBCL and Clozure CL so far. +Classes should work everywhere with MOP.
+ +Customization
+ +There are different styles of how symbols are presented in
+defpackage, the default is to use uninterned symbols (#:foo).
+This can be changed:
to use keywords:
+ +(setq slime-export-symbol-representation-function
+ (lambda (n) (format ":%s" n)))
+or strings:
+ +(setq slime-export-symbol-representation-function
+ (lambda (n) (format "\"%s\"" (upcase n))))
+Crossreferencing: find who’s calling, referencing, setting a symbol
+ +Slime has a nice cross referencing facility, for example, you can see +what calls a particular function or expands a macro. It presents a +list of places which reference a particular entity, from there you can +recompile the thing which references by pressing C-c C-c on that +line. C-c C-k will recompile all the references. This is useful when +modifying macros, inline functions, or constants.
+ +The following bindings are also shown in Slime’s menu:
+ +-
+
- C-c C-w c slime-who-calls callers of a function +
- C-c C-w m slime-who-macroexpands places where a macro is expanded +
- C-c C-w r slime-who-references global variable references +
- C-c C-w b slime-who-bind global variable bindings +
- C-c C-w s slime-who-sets global variable setters +
- C-c C-w a slime-who-specializes methods specialized on a symbol +
And when the slime-asdf contrib is enabled,
+C-c C-w d slime-who-depends-on lists dependent ASDF systems
And a general binding: M-? or M-_ *slime-edit-uses** combines all +of the above, it lists every kind of references.
+ +Monitoring and controlling threads with Slime
+ +M-x slime-list-threads (you can also access it through the +slime-selector, shortcut t) will list running threads by their +names, and their statuses.
+ +The thread on the current line can be killed with k, or if there’s a +lot of threads to kill, several lines can be selected and k will kill +all the threads in the selected region.
+ +g will update the thread list, but when you have a lot of threads
+starting and stopping it may be too cumbersome to always press g, so
+there’s a variable slime-threads-update-interval, when set to a number
+X the thread list will be automatically updated each X seconds, a
+reasonable value would be 0.5.
+
+
+
+ Lanzando Tipicolis, mi proyecto personal dirigido a apoyar a productores gastronómicos locales
+Javier Archeni 23 08 2019
+
+
+ Things You Didn’t Know About GNU Readline
+Two-Bit History 22 08 2019
+
+ 
+
+
+ Platypuscorn
+MonkeyUser 20 08 2019
+
+ 
+
+
+ Brittle
+MonkeyUser 13 08 2019
+
+
+ How to Get the First or Last Value in a Group Using Group By in SQL
+Haki Benita 12 08 2019
+Getting the last value of a group in an aggregated query in PostgreSQL is a challenging task. In this article we present a simple way to get the first or last value of a group using group by.
+
+ 
+
+
+ 7 consejos para diseño de tablas comparativas
+Blog de Diseño Web Vida MRR 12 08 2019
+
1. Resalta atributos importantes
Este es el primer consejo. Cuando construimos sitios interactivos es fundamental saber qué atributos debemos resaltar como por ejemplo el precio de la opción que más recomendamos a los usuarios, o características que no tienen las demás opciones. Esto es para que el usuario tenga presente esas cualidades y que al momento de tomar su decisión siempre recuerde las características resaltadas.
2. El problema del contenido
Las tablas comparativas no deberían tener mucho contenido por celda, pero tampoco debería haber celdas sin contenido, ya que esto hace ver a la tabla vacía. Lo importante es siempre acotar el contenido con características puntuales, y si es posible poner un link a otra sección para explicar mejor. Las opciones donde no haya contenido que poner, ya sea porque esa opción o columna no tiene características de los demás niveles, siempre es preferible poner que no existe, no aplica, o alguna marca que indique que ese campo es vacío. Este tema afecta mucho al usuario ya que si no ve nada en la celda pensará que faltó ponerle contenido o lo dejará con la duda de si aplica o no.
3. Agrupa atributos
Una forma visual de poder navegar en una tabla comparativa es con el uso de grupos, o cabeceras, para que si tu tabla va a tener muchas filas de contenido, mejor las agrupes y el usuario pueda consultar aquellos atributos que le son más interesantes en ese momento.
4. Resalta de acuerdo a la necesidad
Una forma más dinámica para una tabla comparativa puede ser resaltar atributos que busque el cliente, por ejemplo, el producto más barato, o el que tiene más beneficios, o el más popular. No hagamos solo estático el resaltado de atributos, sino que también démosle al usuario la oportunidad de tener varios resaltados.
5. Mantén un balance en el diseño
Lo más simple siempre va a ser mejor. Las tablas comparativas no deberían tener simbologías complejas, detalles o links adicionales, solo los atributos importantes, las imágenes y resaltados fundamentales para que haya un balance entre la tabla y el contenido. Recuerda que al final el usuario solo quiere comparar de un vistazo dos productos o servicios, no hace falta complicar mucho el diseño.
6. Haz tu tabla fácil de compartir
Sobre todo en productos donde el precio es considerable siempre ten en mente que alguien va a sacar un screenshot en su computadora o pantalla, por lo que trata de mantener una tabla libre de scrolls, de paneles colapsables o de tablas muy grandes que no permitan tener en una pantalla mediana o pequeña la comparación. Si es posible trata de tener esa misma tabla en formato de imagen para que peuda ser compartida en las redes sociales.
7. No uses muchos colores para resaltar
Basta con tener un solo color para resaltar los puntos importantes de una tabla comparativa. El uso exagerado de colores para resaltar, o un esquema complejo para identificar similitudes y diferencias solo hará que el usuario busque comparar en otro sitio o simplemente la decisión de comparar tus productos y servicios se extinga.
Vía line25
+ 
+
+
+
+
+ Crear una cuenta de correo electrónico gratuita con tu propio dominio gracias a Migadu
+Javier Archeni 11 08 2019
+
+ 
+
+
+ _
+MonkeyUser 06 08 2019
+
+
+ Q3 2019 Funding Announcement
+News on Clojurists Together 05 08 2019
+
+
+ July 2019 Monthly Update
+News on Clojurists Together 05 08 2019
+
+
+ What You Need to Know to Manage Users in Django Admin
+Haki Benita 04 08 2019
+Have you ever stopped to think what staff user can do in your Django admin site? Did you know staff users with misconfigured permissions on the user model can make themselves superusers? Permissive permissions to staff users can cause disastrous human errors at best, and lead to major data leaks and at worst.
+
+ 
+
+
+ The Superficial High
+MonkeyUser 30 07 2019
+
+ 
+
+
+ 30 cosas que me gustaría haber sabido cuando empecé a programar
+Blog de Diseño Web Vida MRR 29 07 2019
+
Entrar al mundo de la programación puede ser sencillo o muy difícil dependiendo del contexto de la persona. De hecho, creo que aunque hoy hay muchísma más información que hace cinco años, la dificultad todavía es un poco elevada para alguien que nunca ha estado en contacto con el mundo de la programación, especialmente si se adentra directo en ella. En este post les voy a compartir algunas ideas de lo que me hubiera gustado conocer cuando empecé con la programación, que tal vez a ti si te sirvan y con eso puedas tener una curva de aprendizaje mucho más rápida en menos tiempo.
- No necesitas un grado universitario para ser desarrollador, pero sí necesitas tener conocimientos de ingeniería
- La programación no solo es resolver problemas, sino también usar la creatividad para poder encontrar diferentes formas de resolver problemas
- No puedes aprender todo sobre programación, es imposible, pero sí puedes aprender cosas básicas que te pueden servir en cualquier momento, todas las áreas de la programación comparten cosas similares, y cada una ofrece algo más específico.
- Date un descanso en la programación, no es cierto que tengas que estar horas en la computadora para ser mejor, requiere esfuerzo pero no dejar tu vida personal
- Programar es acerca de entender conceptos y aplicarlos, no de memorizar código, nadie que intente memorizar código puede ser considerado un programador
- Siempre habrá alguien que sepa más que tu, y es normal, pasa con todas las áreas de estudio, lo importante es que tu sepas lo que necesitas aprender y lo aprendas.
- No seas adicto a la programación, sal, juega, ten una relación; que ser programador no sea lo primero, sino lo que te complementa después de tener una vida propia
- Aprenderás a programar si te pones retos contigo mismo, es decir, si te pones objetivos de programas, funciones, o ciertas cosas que necesitas hacer en un determinado tiempo (y que sea técnicamente realista)
- Al contrario de lo que dicen, no es 100% cierto que necesites saber matemáticas para ser buen programador, como lo dije antes, hay diferentes áreas de aplicación, y no todas requieren que seas bueno, pero sí que conozcas las operaciones básicas de suma, resta, multiplicación y división.
- No necesitas ponerte un estereotipo de novato en programación, hay mucha gente que puede saber otros lenguajes y no uno específico, y no por eso se considera novato, simplemente estás aprendiendo.
- Trata de terminar tus proyectos, porque de esa forma podrás llegar a un objetivo inicial, que es terminar algo.
- Te traumarás eventualmente por encontrar el error que evita que funcione tu programa correctamente, y es algo normal
- Es normal que busques en internet cómo se hace determinada cosa para tu programa, como dije, no es buen programador el que memoriza, sino el que usa lo sabe para programar mejor, y buscar es una buena habilidad
- Necesitas no solo programar sino también guiarte en prácticas recomendadas, inicia tu vida de programador también aprendiendo los consejos de patrones de diseño de programación
- Una obsesión más será el poner nombres correctos a tus variables y funciones, es totalmente normal y siempre pensarás que pueden llamarse de otra forma
- Un trauma común es programar con nombres en inglés o español, o si es deEstaForma o de_esta_otra_forma, cualquiera de las opciones es válida, lo importante es que tu código sea entendible
- Es bueno darse por vencido, porque en algún proyecto puede que veas que necesitas otros conocimientos para terminar esa parte que te faltaba. De aquí en adelante si lo que deseas es seguir aprendiendo, hazlo y vuelve a interntarlo
- Si ves que un programa ya se hizo muy elaborado o complicado vuelve a empezar desde cero, eso te dará la oportunidad de volverlo a hacer de otra forma, y no tratar de arreglar algo que quizá ya no tiene solución
- Cuando estés programando te empezarás a preguntar si lo que haces es la mejor forma de hacerlo, no pierdas esa curiosidad
- Programar por gusto no es lo mismo que trabajar en programar. Lo primero te va a encantar, y lo segundo no, pero es algo que tienes que identificar para no odiar la programación
- Es completamente normal no pasar una entrevista técnica de programación, mas si nunca has practicado problemas de lógica realmente difíciles
- Siempre creete que eres bueno, pero no lo suficiente para perder el piso y creer que nadie puede contra ti
- Habrá quien te diga que lo que haces está mal, pero si no te ayuda a mejorar puedes hacer caso omiso de esos comentarios
- Trata de buscar programadores que admires, porque de esa forma querrás tener una visión de ti mismo en un futuro
- Siempre es difícil trabajar en equipo para un proyecto, porque no es la misma técnica para todos, pero trata siempre de demostrar por qué deberían hacer las cosas de cierta forma
- Si revisas después de un año el código de algún proyecto, te vas a dar cuenta que pudo haber sido mejor, toma ese feedback y aplícalo en el siguiente proyecto que hagas
- Siempre tenemos un momentum, ese instante donde a pesar de que ya quieres terminar algo no te deja descansar. Si te pasa eso es que realmente te gusta la programación, pero evita que pase seguido
- Odiarás y amarás los hackatones porque te permite ponerte a prueba contra el tiempo, pero te dolerá si lo tuyo no es la presión
- No todo va a ser copiar código de páginas como Stack overflow, también necesitas entender el por qué de una solución que buscas
- La programación con música es mucho mejor, inténtalo
+ 
+
+
+
+
+ Tailwind CSS, disciplina y diversión a partes iguales para diseñar tus proyectos web
+Javier Archeni 29 07 2019
+
+
+ Clojure Forum
+Clojure News 25 07 2019
+
+
+We are pleased to announce today a new forum for Clojure and ClojureScript users: https://ask.clojure.org. You can ask questions, discuss possible problems, request enhancements, and vote on questions and answers.
+
+
+The new forum was seeded with all of the open JIRA issues, one question per issue with JIRA comments turned into answers. Over time, we expect this site to serve as a persistent store of common questions, answers, etc - it is open for web indexing and has both search and "similar question" functionality to help you find previous related discussions. This addresses one of the biggest issues with current places to ask questions about Clojure - the ability to search and find similar prior discussions.
+
+
+For problems and enhancements, we have been using JIRA for years (and will continue to do so). However, there are naturally two audiences for issues, users and developers, who have different needs. The new forum will serve as the primary place for users to ask questions about potential problems or request possible enhancments. Authentication occurs via GitHub (other auth providers may be added in the future). No contributor agreement is needed.
+
+
+Developers on Clojure, ClojureScript, etc will monitor these forums and create JIRAs when necessary. Any user may vote on questions in the forum and the dev teams can use this information when prioritizing fixes and enhancements. This capability has been available in JIRA for many years, but it was too much of a barrier to receive feedback from casual users. The new forum greatly reduces this friction. JIRA will still be used by developers submitting and working on patches, but not for initial problem reporting.
+
+
+
+ For more information see the forum usage details.
+
+ 
+
+
+ PTSD
+MonkeyUser 23 07 2019
+
+
+
+
+ 50 años de la llegada a la Luna
+Sección Materia | Ciencia en EL PAÍS 22 07 2019
+
+
+
+
+ Motivos para desconfiar de las buenas prácticas en tu marketing digital
+Javier Archeni 17 07 2019
+
+
+ Q3 2019 Survey Results and Call for Proposals
+News on Clojurists Together 12 07 2019
+
+
+ How to Check Slots Types at make-instance
+Lisp journey 10 07 2019
+In CLOS, a slot can have a :type option, but it doesn’t inforce type
+checking. It is good practice to use it, for documentation and for
+compiler optimizations and warnings sometimes (with CCL and SBCL when
+safety is high), but one shouldn’t rely on it. To comply this need, we
+can simply create our own constructor functions.
However, the +sanity-clause library can +do it since a couple of days. The validation error messages are +pretty good. Demonstration.
+ +++ +Sanity clause is a data validation/contract library. You might use it for configuration data, validating an api response, or documents from a datastore. In a dynamically typed langauge, it helps you define clearly defined areas of doubt and uncertainty. We should love our users, but we should never blindly trust their inputs.
+ +To make use of it, you define schemas, which can be property lists with symbols for keys and instances of :class:sanity-clause.field:field
+
We define a class person with slot options from sanity-clause:
+:field-type, type :members, :required:
(defclass person ()
+ ((favorite-dog :type symbol
+ :field-type :member
+ :members (:wedge :walter)
+ :initarg :favorite-dog
+ :required t)
+ (age :type (integer 0)
+ :initarg :age
+ :required t)
+ (potato :type string
+ :initarg :potato
+ :required t))
+ (:metaclass sanity-clause.metaclass:validated-metaclass))
+Now we try to create a person with make-instance, but we give a bad dog name:
(make-instance 'person :favorite-dog :nope)
+; Evaluation aborted on Error converting value for field #<MEMBER-FIELD {1004BFA973}>:
+Value "NOPE" couldn't be found in set (WEDGE WALTER)
+Now with a bad age:
+ +(make-instance 'person :age -1 :favorite-dog :walter)
+; Evaluation aborted on Error validating value -1 in field #<INTEGER-FIELD {1004BFF103}>:
+* Value -1 didn't satisfy condition "must be larger than 0"
+When a required field is missing:
+ +(make-instance 'person :age 7 :favorite-dog :walter)
+; Evaluation aborted on A value for field POTATO is required but none was provided..
+And well, it works when all is OK :]
+ +(make-instance 'person :age 1 :favorite-dog :walter :potato "patate")
+#<PERSON {10060371E3}>
+The usual warnings apply: it’s a new library, we must try it and use +it with caution. It however opens up more possibilities. It would be +awesome to couple it with an ORM like Mito. This is an open +issue.
+ +Resources:
+ + + +
+ 
+
+
+ Bug Fixing Ways
+MonkeyUser 09 07 2019
+
+
+ Fastest Way to Load Data Into PostgreSQL Using Python
+Haki Benita 08 07 2019
+Explore the best way to import messy data from remote source into PostgreSQL using Python and Psycopg2. The data is big, fetched from a remote source, and needs to be cleaned and transformed.
+
+
+ Little Known Vim Command – Join
+Jovica Ilic 08 07 2019
+As the author of Mastering Vim Quickly I sometimes get various Vim related questions from my readers. Much more often I get emails from my subscribers at masteringvim.com where I share free Vim tips. Although this command is very simple, my experience showed that a lot of people are not aware of it. So it’s... Continue reading
+The post Little Known Vim Command – Join appeared first on Jovica Ilic.
+ +
+
+
+
+ Web Development in Common Lisp: frameworks overview, templating, deployment
+Lisp journey 07 07 2019
+We just published a long overdue page on the Cookbook: web +development in Common +Lisp. We have an +ambivalent feeling about it since it isn’t really a recipe as in the +other pages. Yet it is valuable content that required a certain amount +of digging and tryouts. Indeed, it took us about two years to discover +and advertise many projects, to learn, try and put a tutorial +together. We also wrote a commercial application. During that time, we +were taking notes on our web-dev/ page.
+ +We present Hunchentoot, Clack (briefly), we have an overview of other +web frameworks, of templating libraries, we introduce Weblocks, we give +recipes for common tasks (such as checking if a user is logged in, +encrypting passwords), and we speak about deployment.
+ +Some topics still need to be adressed, so check for updates on the Cookbook !
+ ++ +
Prior notice:
+ +Some people sell ten pages long ebooks or publish their tutorial on +Gitbook to have a purchase option. I prefer to enhance the +collaborative Cookbook (I am by far the main +contributor). You +can tip me on liberapay if you like: +https://liberapay.com/vindarel/. Thanks !
+ ++ +
For web development as for any other task, one can leverage Common
+Lisp’s advantages: the unmatched REPL and exception handling system,
+performance, the ability to build a self-contained executable,
+stability, good threads story, strong typing, etc. We can, say, define
+a new route and try it right away, there is no need to restart any
+running server. We can change and compile one function at a time
+(the usual C-c C-c in Slime) and try it. The feedback is
+immediate. We can choose the degree of interactivity: the web server
+can catch exceptions and fire the interactive debugger, or print lisp
+backtraces on the browser, or display a 404 error page and print logs
+on standard output. The ability to build self-contained executables eases
+deployment tremendously (compared to, for example, npm-based apps), in
+that we just copy the executable to a server and run it.
We’ll present here some established web frameworks and other common +libraries to help you getting started in developing a web +application. We do not aim to be exhaustive nor to replace the +upstream documentation. Your feedback and contributions are +appreciated.
+ + + + + + + +Table of Contents
+ +-
+
- Overview +
- Installation +
- Simple webserver
+
+
-
+
- Serve local files
+
+
-
+
- Hunchentoot +
+
+ - Serve local files
+
+
- Access your server from the internet
+
+
-
+
- Hunchentoot +
+ - Routing
+
+
-
+
- Simple routes
+
+
-
+
- Hunchentoot +
- Caveman +
+ - Accessing GET and POST parameters
+
+
-
+
- Hunchentoot +
+
+ - Simple routes
+
+
- Error handling
+
+
-
+
- Hunchentoot +
- Clack +
+ - Weblocks - solving the “JavaScript problem”© +
- Templates + + +
- Connecting to a database + + +
- Building + + +
- Deployment + + +
- Credits +
Overview
+ +Hunchentoot and Clack are two projects that +you’ll often hear about.
+ +Hunchentoot is
+ +++ +a web server and at the same time a toolkit for building dynamic websites. As a stand-alone web server, Hunchentoot is capable of HTTP/1.1 chunking (both directions), persistent connections (keep-alive), and SSL. It provides facilities like automatic session handling (with and without cookies), logging, customizable error handling, and easy access to GET and POST parameters sent by the client.
+
It is a software written by Edi Weitz (“Common Lisp Recipes”,
+cl-ppcre and much more), it’s used and
+proven solid. One can achieve a lot with it, but sometimes with more
+friction than with a traditional web framework. For example,
+dispatching a route by the HTTP method is a bit convoluted, one must
+write a function for the :uri parameter that does the check, when it
+is a built-in keyword in other frameworks like Caveman.
Clack is
+ +++ +a web application environment for Common Lisp inspired by Python’s WSGI and Ruby’s Rack.
+
Also written by a prolific lisper +(E. Fukamachi), it actually uses +Hunchentoot by default as the server, but thanks to its pluggable +architecture one can use another web server, like the asynchronous +Woo, built on the +libev event loop, maybe +“the fastest web server written in any programming language”.
+ +We’ll cite also Wookie, an asynchronous HTTP server, and its +companion library +cl-async, for general +purpose, non-blocking programming in Common Lisp, built on libuv, the +backend library in Node.js.
+ +Clack being more recent and less documented, and Hunchentoot a +de-facto standard, we’ll concentrate on the latter for this +recipe. Your contributions are of course welcome.
+ +Web frameworks build upon web servers and can provide facilities for +common activities in web development, like a templating system, access +to a database, session management, or facilities to build a REST api.
+ +Some web frameworks include:
+ +-
+
- Caveman, by E. Fukamachi. It provides, out of the box, +database management, a templating engine (Djula), a project skeleton +generator, a routing system à la Flask or Sinatra, deployment options +(mod_lisp or FastCGI), support for Roswell on the command line, etc. +
- Radiance, by Shinmera +(Qtools, Portacle, lquery, …), is a web application environment, +more general than usual web frameworks. It lets us write and tie +websites and applications together, easing their deployment as a +whole. It has thorough documentation, a tutorial, modules, pre-written applications such as an image board or a blogging platform, and more. +For example websites, see +https://shinmera.com/, +reader.tymoon.eu and events.tymoon.eu. +
- Snooze, by João Távora (Sly, Emacs’ Yasnippet, Eglot, …), +is “an URL router designed around REST web services”. It is +different because in Snooze, routes are just functions and HTTP +conditions are just Lisp conditions. +
- cl-rest-server is a library for writing REST web +APIs. It features validation with schemas, annotations for logging, +caching, permissions or authentication, documentation via OpenAPI (Swagger), +etc. +
- last but not least, Weblocks is a venerable Common Lisp +web framework that permits to write ajax-based dynamic web +applications without writing any JavaScript, nor writing some lisp +that would transpile to JavaScript. It is seeing an extensive +rewrite and update since 2017. We present it in more details below. +
For a full list of libraries for the web, please see the awesome-cl +list +#network-and-internet +and Cliki. If you are looking for a +featureful static site generator, see +Coleslaw.
+ +Installation
+ +Let’s install the libraries we’ll use:
+ +(ql:quickload '("hunchentoot" "caveman" "spinneret" "djula"))
+To try Weblocks, please see its documentation. The Weblocks in +Quicklisp is not yet, as of writing, the one we are interested in.
+ +We’ll start by serving local files and we’ll run more than one local +server in the running image.
+ +Simple webserver
+ +Serve local files
+ +Hunchentoot
+ +Create and start a webserver like this:
+ +(defvar *acceptor* (make-instance 'hunchentoot:easy-acceptor :port 4242))
+(hunchentoot:start *acceptor*)
+We create an instance of easy-acceptor on port 4242 and we start
+it. We can now access http://127.0.0.1:4242/. You should get a welcome
+screen with a link to the documentation and logs to the console.
By default, Hunchentoot serves the files from the www/ directory in
+its source tree. Thus, if you go to the source of
+easy-acceptor (M-. in Slime), which is probably
+~/quicklisp/dists/quicklisp/software/hunchentoot-v1.2.38/, you’ll
+find the root/ directory. It contains:
-
+
- an
errors/directory, with the error templates404.htmland500.html,
+ - an
img/directory,
+ - an
index.htmlfile.
+
To serve another directory, we give the option document-root to
+easy-acceptor. We can also set the slot with its accessor:
(setf (hunchentoot:acceptor-document-root *acceptor*) #p"path/to/www")
+Let’s create our index.html first. Put this in a new
+www/index.html at the current directory (of the lisp repl):
<html>
+ <head>
+ <title>Hello!</title>
+ </head>
+ <body>
+ <h1>Hello local server!</h1>
+ <p>
+ We just served our own files.
+ </p>
+ </body>
+</html>
+Let’s start a new acceptor on a new port:
+ +(defvar *my-acceptor* (make-instance 'hunchentoot:easy-acceptor :port 4444
+ :document-root #p"www/"))
+(hunchentoot:start *my-acceptor*)
+go to p://127.0.0.1:4444/ and see the difference.
+ +Note that we just created another acceptor on a different port on +the same lisp image. This is already pretty cool.
+ +Access your server from the internet
+ +Hunchentoot
+ +With Hunchentoot we have nothing to do, we can see the server from the +internet right away.
+ +If you evaluate this on your VPS:
+ +(hunchentoot:start (make-instance 'hunchentoot:easy-acceptor :port 4242))
+You can see it right away on your server’s IP.
+ +Stop it with (hunchentoot:stop *).
Routing
+ +Simple routes
+ +Hunchentoot
+ +To bind an existing function to a route, we create a “prefix dispatch”
+that we push onto the *dispatch-table* list:
(defun hello ()
+ (format nil "Hello, it works!"))
+
+(push
+ (hunchentoot:create-prefix-dispatcher "/hello.html" #'hello)
+ hunchentoot:*dispatch-table*)
+To create a route with a regexp, we use create-regex-dispatcher, where
+the url-as-regexp can be a string, an s-expression or a cl-ppcre scanner.
If you didn’t yet, create an acceptor and start the server:
+ +(defvar *server* (make-instance 'hunchentoot:easy-acceptor :port 4242))
+(hunchentoot:start *server*)
+and access it on [http://localhost:4242/hello.html]http://localhost:4242/hello.html).
+ +We can see logs on the REPL:
+ +127.0.0.1 - [2018-10-27 23:50:09] "get / http/1.1" 200 393 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0"
+127.0.0.1 - [2018-10-27 23:50:10] "get /img/made-with-lisp-logo.jpg http/1.1" 200 12583 "http://localhost:4242/" "Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0"
+127.0.0.1 - [2018-10-27 23:50:10] "get /favicon.ico http/1.1" 200 1406 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0"
+127.0.0.1 - [2018-10-27 23:50:19] "get /hello.html http/1.1" 200 20 "-" "Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0"
++ +
define-easy-handler allows to create a function and to bind it to an uri at once.
+ +Its form follows
+ +define-easy-handler (function-name :uri <uri> …) (lambda list parameters)
+where <uri> can be a string or a function.
Example:
+ +(hunchentoot:define-easy-handler (say-yo :uri "/yo") (name)
+ (setf (hunchentoot:content-type*) "text/plain")
+ (format nil "Hey~@[ ~A~]!" name))
+Visit it at p://localhost:4242/yo and add parameters on the url: +http://localhost:4242/yo?name=Alice.
+ +Just a thought… we didn’t explicitely ask Hunchentoot to add this
+route to our first acceptor of the port 4242. Let’s try another acceptor (see
+previous section), on port 4444: http://localhost:4444/yo?name=Bob It
+works too ! In fact, define-easy-handler accepts an acceptor-names
+parameter:
++ +acceptor-names (which is evaluated) can be a list of symbols which means that the handler will only be returned by DISPATCH-EASY-HANDLERS in acceptors which have one of these names (see ACCEPTOR-NAME). acceptor-names can also be the symbol T which means that the handler will be returned by DISPATCH-EASY-HANDLERS in every acceptor.
+
So, define-easy-handler has the following signature:
define-easy-handler (function-name &key uri acceptor-names default-request-type) (lambda list parameters)
+It also has a default-parameter-type which we’ll use in a minute to get url parameters.
There are also keys to know for the lambda list. Please see the documentation.
+ +Caveman
+ +Caveman provides two ways to
+define a route: the defroute macro and the @route pythonic
+annotation:
(defroute "/welcome" (&key (|name| "Guest"))
+ (format nil "Welcome, ~A" |name|))
+
+@route GET "/welcome"
+(lambda (&key (|name| "Guest"))
+ (format nil "Welcome, ~A" |name|))
+A route with an url parameter (note :name in the url):
(defroute "/hello/:name" (&key name)
+ (format nil "Hello, ~A" name))
+It is also possible to define “wildcards” parameters. It works with
+the splat key:
(defroute "/say/*/to/*" (&key splat)
+ ; matches /say/hello/to/world
+ (format nil "~A" splat))
+;=> (hello world)
+We must enable regexps with :regexp t:
(defroute ("/hello/([\\w]+)" :regexp t) (&key captures)
+ (format nil "Hello, ~A!" (first captures)))
+Accessing GET and POST parameters
+ +Hunchentoot
+ +First of all, note that we can access query parameters anytime with
+ +(hunchentoot:parameter "my-param")
+It acts on the default *request* object which is passed to all handlers.
There is also get-paramater and post-parameter.
Earlier we saw some key parameters to define-easy-handler. We now
+introduce default-parameter-type.
We defined the following handler:
+ +(hunchentoot:define-easy-handler (say-yo :uri "/yo") (name)
+ (setf (hunchentoot:content-type*) "text/plain")
+ (format nil "Hey~@[ ~A~]!" name))
+The variable name is a string by default. Let’s check it out:
(hunchentoot:define-easy-handler (say-yo :uri "/yo") (name)
+ (setf (hunchentoot:content-type*) "text/plain")
+ (format nil "Hey~@[ ~A~] you are of type ~a" name (type-of name)))
+Going to http://localhost:4242/yo?name=Alice returns
+ +Hey Alice you are of type (SIMPLE-ARRAY CHARACTER (5))
+To automatically bind it to another type, we use default-parameter-type. It can be
+one of those simple types:
-
+
'string(default),
+'integer,
+'character(accepting strings of length 1 only, otherwise it is nil)
+- or
'boolean
+
or a compound list:
+ +-
+
'(:list <type>)
+'(:array <type>)
+'(:hash-table <type>)
+
where <type> is a simple type.
Error handling
+ +In all frameworks, we can choose the level of interactivity. The web +framework can return a 404 page and print output on the repl, it can +catch errors and invoke the interactive lisp debugger, or it can show +the lisp backtrace on the html page.
+ +Hunchentoot
+ +The global variables to set are *catch-errors-p*,
+*show-lisp-errors-p* and *show-lisp-backtraces-p*.
Hunchentoot also defines condition classes.
+ +See the documentation: https://edicl.github.io/hunchentoot/#conditions.
+ +Clack
+ +Clack users might make a good use of plugins, like the clack-errors middleware: https://github.com/CodyReichert/awesome-cl#clack-plugins.
+ +Weblocks - solving the “JavaScript problem”©
+ +Weblocks is a widgets-based and +server-based framework with a built-in ajax update mechanism. It +allows to write dynamic web applications without the need to write +JavaScript or to write lisp code that would transpile to JavaScript.
+ +
Weblocks is an old framework developed by Slava Akhmechet, Stephen +Compall and Leslie Polzer. After nine calm years, it is seeing a very +active update, refactoring and rewrite effort by Alexander Artemenko.
+ +It was initially based on continuations (they were removed to date) +and thus a lispy cousin of Smalltalk’s +Seaside. We can +also relate it to Haskell’s Haste, OCaml’s Eliom, +Elixir’s Phoenix LiveView and others.
+ +The Ultralisp website is an example Weblocks +website in production known in the CL community.
+ ++ +
Weblock’s unit of work is the widget. They look like a class definition:
+ +(defwidget task ()
+ ((title
+ :initarg :title
+ :accessor title)
+ (done
+ :initarg :done
+ :initform nil
+ :accessor done)))
+Then all we have to do is to define the render method for this widget:
(defmethod render ((task task))
+ "Render a task."
+ (with-html
+ (:span (if (done task)
+ (with-html
+ (:s (title task)))
+ (title task)))))
+It uses the Spinneret template engine by default, but we can bind any +other one of our choice.
+ +To trigger an ajax event, we write lambdas in full Common Lisp:
+ +...
+(with-html
+ (:p (:input :type "checkbox"
+ :checked (done task)
+ :onclick (make-js-action
+ (lambda (&key &allow-other-keys)
+ (toggle task))))
+...
+The function make-js-action creates a simple javascript function
+that calls the lisp one on the server, and automatically refreshes the
+HTML of the widgets that need it. In our example, it re-renders one
+task only.
Is it appealing ? Carry on this quickstart guide here: http://40ants.com/weblocks/quickstart.html.
+ +Templates
+ +Djula - HTML markup
+ +Djula is a port of Python’s +Django template engine to Common Lisp. It has excellent documentation.
+ +Caveman uses it by default, but otherwise it is not difficult to +setup. We must declare where our templates are with something like
+ +(djula:add-template-directory (asdf:system-relative-pathname "webapp" "templates/"))
+A Djula template looks like this, no surprises (forgive the antislash
+in \%, this is a Jekyll limitation):
{\% extends "base.html" \%}
+{\% block title %}Memberlist{\% endblock \%}
+{\% block content \%}
+ <ul>
+ {\% for user in users \%}
+ <li><a href="{{ user.url }}">{{ user.username }}</a></li>
+ {\% endfor \%}
+ </ul>
+{\% endblock \%}
+Djula compiles the templates before rendering them.
+ +It is, along with its companion +access library, one of +the most downloaded libraries of Quicklisp.
+ +Spinneret - lispy templates
+ +Spinneret is a “lispy” +HTML5 generator. It looks like this:
+ +(with-page (:title "Home page")
+ (:header
+ (:h1 "Home page"))
+ (:section
+ ("~A, here is *your* shopping list: " *user-name*)
+ (:ol (dolist (item *shopping-list*)
+ (:li (1+ (random 10)) item))))
+ (:footer ("Last login: ~A" *last-login*)))
+The author finds it is easier to compose the HTML in separate +functions and macros than with the more famous cl-who. But it +has more features under it sleeves:
+ +-
+
- it warns on invalid tags and attributes +
- it can automatically number headers, given their depth +
- it pretty prints html per default, with control over line breaks +
- it understands embedded markdown +
- it can tell where in the document a generator function is (see
get-html-tag)
+
Connecting to a database
+ +Please see the databases section. The Mito ORM +supports SQLite3, PostgreSQL, MySQL, it has migrations and db schema +versioning, etc.
+ +In Caveman, a database connection is alive during the Lisp session and is +reused in each HTTP requests.
+ +Checking a user is logged-in
+ +A framework will provide a way to work with sessions. We’ll create a +little macro to wrap our routes to check if the user is logged in.
+ +In Caveman, *session* is a hash table that represents the session’s
+data. Here are our login and logout functions:
(defun login (user)
+ "Log the user into the session"
+ (setf (gethash :user *session*) user))
+
+(defun logout ()
+ "Log the user out of the session."
+ (setf (gethash :user *session*) nil))
+We define a simple predicate:
+ +(defun logged-in-p ()
+ (gethash :user cm:*session*))
+and we define our with-logged-in macro:
(defmacro with-logged-in (&body body)
+ `(if (logged-in-p)
+ (progn ,@body)
+ (render #p"login.html"
+ '(:message "Please log-in to access this page."))))
+If the user isn’t logged in, there will nothing in the session store, +and we render the login page. When all is well, we execute the macro’s +body. We use it like this:
+ +(defroute "/account/logout" ()
+ "Show the log-out page, only if the user is logged in."
+ (with-logged-in
+ (logout)
+ (render #p"logout.html")))
+
+(defroute ("/account/review" :method :get) ()
+ (with-logged-in
+ (render #p"review.html"
+ (list :review (get-review (gethash :user *session*))))))
+and so on.
+ +Encrypting passwords
+ +In this recipe we use the de-facto standard +Ironclad cryptographic toolkit +and the Babel charset +encoding/decoding library.
+ +This snippet creates the password hash that should be stored in your +database. Note that Ironclad expects a byte-vector, not a string.
+ +(defun password-hash (password)
+ (ironclad:pbkdf2-hash-password-to-combined-string
+ (babel:string-to-octets password)))
+pbkdf2 is defined in RFC2898.
+It uses a pseudorandom function to derive a secure encryption key
+based on the password.
The following function checks if a user is active and verifies the +entered password. It returns the user-id if active and verified and +nil in all other cases even if an error occurs. Adapt it to your +application.
+ +(defun check-user-password (user password)
+ (handler-case
+ (let* ((data (my-get-user-data user))
+ (hash (my-get-user-hash data))
+ (active (my-get-user-active data)))
+ (when (and active (ironclad:pbkdf2-check-password (babel:string-to-octets password)
+ hash))
+ (my-get-user-id data)))
+ (condition () nil)))
+And the following is an example on how to set the password on the
+database. Note that we use (password-hash password) to save the
+password. The rest is specific to the web framework and to the DB
+library.
(defun set-password (user password)
+ (with-connection (db)
+ (execute
+ (make-statement :update :web_user
+ (set= :hash (password-hash password))
+ (make-clause :where
+ (make-op := (if (integerp user)
+ :id_user
+ :email)
+ user))))))
+Credit: /u/arvid on /r/learnlisp.
Building
+ +Building a self-contained executable
+ +As for all Common Lisp applications, we can bundle our web app in one +single executable, including the assets. It makes deployment very +easy: copy it to your server and run it.
+ +$ ./my-web-app
+Hunchentoot server is started.
+Listening on localhost:9003.
+See this recipe on scripting#for-web-apps.
+ +Continuous delivery with Travis CI or Gitlab CI
+ +Please see the section on testing#continuous-integration.
+ +Multiplatform delivery with Electron
+ +Ceramic makes all the work for us.
+ +It is as simple as this:
+ +;; Load Ceramic and our app
+(ql:quickload '(:ceramic :our-app))
+
+;; Ensure Ceramic is set up
+(ceramic:setup)
+(ceramic:interactive)
+
+;; Start our app (here based on the Lucerne framework)
+(lucerne:start our-app.views:app :port 8000)
+
+;; Open a browser window to it
+(defvar window (ceramic:make-window :url "http://localhost:8000/"))
+
+;; start Ceramic
+(ceramic:show-window window)
+and we can ship this on Linux, Mac and Windows.
+ +There is more:
+ +++ +Ceramic applications are compiled down to native code, ensuring both performance and enabling you to deliver closed-source, commercial applications.
+
Thus, no need to minify our JS.
+ +Deployment
+ +Deploying manually
+ +We can start our executable in a shell and send it to the bakcground (C-z bg), or run it inside a tmux session. These are not the best but hey, it works©.
Daemonizing, restarting in case of crashes, handling logs with Systemd
+ +This is actually a system-specific task. See how to do that on your system.
+ +Most GNU/Linux distros now come with Systemd, so here’s a little example.
+ +Deploying an app with Systemd is as simple as writing a configuration file:
+ +$ emacs -nw /etc/systemd/system/my-app.service
+[Unit]
+Description=stupid simple example
+
+[Service]
+WorkingDirectory=/path/to/your/app
+ExecStart=/usr/local/bin/sthg sthg
+Type=simple
+Restart=always
+RestartSec=10
+Then we have a command to start it:
+ +sudo systemctl start my-app.service
+a command to check its status:
+ +systemctl status my-app.service
+and Systemd can handle logging (we write to stdout or stderr, it writes logs):
+ +journalctl -f -u my-app.service
+and it handles crashes and restarts the app:
+ +Restart=always
+and it can start the app after a reboot:
+ +[Install]
+WantedBy=basic.target
+to enable it:
+ +sudo systemctl enable my-app.service
+With Docker
+ +There are several Docker images for Common +Lisp. For example:
+ +-
+
- 40ants/base-lisp-image +is based on Ubuntu LTS and includes SBCL, CCL, Quicklisp, Qlot and +Roswell. +
- container-lisp/s2i-lisp +is CentOs based and contains the source for building a Quicklisp based +Common Lisp application as a reproducible docker image using OpenShift’s +source-to-image. +
With Guix
+ +GNU Guix is a transactional +package manager, that can be installed on top of an existing OS, and a +whole distro that supports declarative system configuration. It allows +to ship self-contained tarballs, which also contain system +dependencies. For an example, see the Next browser.
+ +Deploying on Heroku and other services
+ +See heroku-buildpack-common-lisp and the Awesome CL#deploy section for interface libraries for Kubernetes, OpenShift, AWS, etc.
+ +Monitoring
+ +See Prometheus.cl +for a Grafana dashboard for SBCL and Hunchentoot metrics (memory, +threads, requests per second,…).
+ +Connecting to a remote Lisp image
+ +This this section: debugging#remote-debugging.
+ +Hot reload
+ +This is an example from Quickutil. It is actually an automated version of the precedent section.
+ +It has a Makefile target:
+ +hot_deploy:
+ $(call $(LISP), \
+ (ql:quickload :quickutil-server) (ql:quickload :swank-client), \
+ (swank-client:with-slime-connection (conn "localhost" $(SWANK_PORT)) \
+ (swank-client:slime-eval (quote (handler-bind ((error (function continue))) \
+ (ql:quickload :quickutil-utilities) (ql:quickload :quickutil-server) \
+ (funcall (symbol-function (intern "STOP" :quickutil-server))) \
+ (funcall (symbol-function (intern "START" :quickutil-server)) $(start_args)))) conn)) \
+ $($(LISP)-quit))
+It has to be run on the server (a simple fabfile command can call this
+through ssh). Beforehand, a fab update has run git pull on the
+server, so new code is present but not running. It connects to the
+local swank server, loads the new code, stops and starts the app in a
+row.
Credits
+ + + +
+
+ Relatos cortos y cuentos como herramienta para la educación ambiental
+Andanzas de una ambientóloga . . . 07 07 2019
+
+ 
+
+
+ Realiza videos rápidos y profesionales con Flexclip
+Blog de Diseño Web Vida MRR 05 07 2019
+
Flexclip es un servicio que encontré y me pareció de lo más interesante para realizar videos rápidos pero bonitos. Uno de los problemas más grandes que a veces tengo es que si quiero hacer un video rápido, sin necesidad de tener mucha edición, opciones como Adobe Premiere no cumplen su cometido, porque añaden muchísima complejidad a una cinemática con imágenes y texto.
Encontré a Flexclip y creo que de cualquier opción que hayas visto en internet, diría que es la más sencilla de usar con grandes resultados.
Para empezar podemos elegir una temática de un template para no partir desde cero. La ventaja de usar estas opciones es que ya no necesitas nada más que cambiar el texto y las imágenes, por lo que ya te ahorras al menos la mitad del trabajo.
Cuando llegamos a la interfaz no pude estar más impresionado de lo minimalista y funcional que puede ser tener dos o tres herramientas para trabajar. Como les digo, esto es para cuando necesitamos algo rápido, tenemos videos, imágenes y música, y no queremos perder el tiempo en acomodarlos pixel por pixel a ver si queda bien.
Los cuadros de control son muy rápidos de editar, no hace falta gran complejidad para poder meter un texto en un formato ya definido para que puedas ver luego luego el resultado.
Si al contrario, no tenemos ningún contenido para empezar a trabajar, podemos agregar de la galería de Flexclip imágenes y música que sorpresivamente tienen una calidad muy buena.
Al final tu video se presenta como la composición de varias escenas, donde si quieres acomodarlas solo necesitas moverlas de lugar y ya, a previsualizar el video y si te gustó lo puedes exportar.
Conclusiones
Este servicio en línea me recordó mucho a cuando usaba Windows Movie Maker para hacer videos cortos o que por la urgencia necesitaba tener en unos cuantos minutos. No ha vuelto a existir un programa igual, pero me sorprende que los servicios web ahora estén tomando esa responsabilidad de seguir ofreciendo hacer videos como lo hace Flexclip, sin la necesidad de ser un experto en edición para crear un contenido de calidad de forma muy rápida.
+ 
+
+ 
+
+
+ MVP
+MonkeyUser 02 07 2019
+
+
+ Functional JavaScript: What are higher-order functions, and why should anyone care?
+James Sinclair 01 07 2019
+
+
+ Functional JavaScript: What are higher-order functions, and why should anyone care?
+Web Development - James Sinclair 01 07 2019
+
+
+ June 2019 Monthly Update
+News on Clojurists Together 01 07 2019
+
+
+ Recomendaciones para reducir nuestro consumo de plástico
+Andanzas de una ambientóloga . . . 29 06 2019
+
+ 
+
+
+ Obvious
+MonkeyUser 25 06 2019
+
+ 
+
+
+ 7 hábitos de programadores altamente efectivos
+Blog de Diseño Web Vida MRR 24 06 2019
+
1. Aprende a leer el código de los demás
Poder leer código escrito de alguien más te dará más visión sobre si el código que haces es bueno o malo. También es bueno de vez en cuando aprender a entender el código de alguien más porque podrías adoptar técnicas y formas de programar que quizá ni sabías que existían, y de la misma forma hacer que los demás aprendan.
2. La sensación de malos proyectos
¿Les ha pasado que antes de empezar un proyecto pueden empezar a estructurar el futuro del mismo? eso se aprende con la experiencia, con los retrasos o la dificultad de los proyectos cuando no se planean bien. Este punto de aprender a identificar buenos y malos proyectos ayuda mucho porque al final un desarrollador debería ser capaz de determinar la viabilidad de un proyecto, y más cuando no tiene futuro.
3. Evitar las reuniones
Todos odiamos las reuniones largas en un proyecto. Dar estatus, explicaciones y en general, invertir tiempo en explicarle a los demás qué es lo que pasa con un proyecto es algo que siempre deberíamos evitar. No es estar en contra de tener reuniones, pero para dar avances no es necesario tener una reunión diario, con una a la semana, con correos, y con herramientas como Github se puede reemplazar el tener que invertir tiempo innecesario.
4. Uso de Github
Github y Git son de las herramientas indispensables hoy en día para cualquier desarrollador. Ya sea que trabajes de forma local o colaborativa tener un sistema de versionamiento permite tener eficiencia en los cambios que se hacen a un proyecto, especialmente si es grande. El otro plus es que tener un sistema como Github permite que otros vean tu código sin tener que perder tiempo tratando de mostrarles avances a los líderes del proyecto.
5. Escribir código que pueda ser mantenido
Para ser efectivo como programador, uno de los primeros pasos es programar correctamente. De nada sirve tener los puntos anteriores, si cuando inicia otro proyecto no puedas reusar código que podría servirte de nuevo. Hay que aprender a crear código que pueda ser extendido y mantenido, es decir, que puedas quitar, adaptar y volver a usar en n número de proyectos. Cuando logres hacer lo anterior, habrás ahorrado muchísimo tiempo de programación.
6. Aprende a decir no y prioriza
No todo vas a poder hacer, por eso tienes que priorizar las actividades que sí puedes hacer excelente. La parte del éxito de los programadores es poder ejecutar lo que está en su alcance, compartir responsabilidad con un equipo cuando así se necesita, y decir que no cuando no agrega valor la actividad al proyecto. Si sigues ese mismo principio de desechar lo que te puede hacer perder tiempo y no agregar valor a un proyecto de programación puedes entonces priorizar de forma correcta.
7. Pensamiento de diseño operacional
Siempre que trabajamos en un proyecto de programación creemos que con probar los escenarios más obvios, nuestro proyecto ya va a funcionar correctamente. Desde la modificación del código hasta el lanzamiento hay muchísimas variables que podrían afectar el funcionamiento del producto final, por eso un hábito muy identificado en programadores efectivos es que prueban y prueban de todas las formas posibles el software para poder identificar cualquier error posible durante la programación y la liberación. La simple modificación de una línea de código podría afectar otras partes del sistema que probablemente no estemos notando.Conclusiones
Estos son algunos consejos de programadores que no solo programan bien, sino que tienen un panorama mucho más amplio de cómo contribuir a un proyecto con calidad y acertividad cuando se colabora con otros.
+ 
+
+
+ Microplásticos. Enemigos del mar IV
+Andanzas de una ambientóloga . . . 20 06 2019
+
+ 
+
+
+ A QA walks into the office
+MonkeyUser 18 06 2019
+
+
+
+
+ Chrome's Manifest V3 - Improving Privacy?
+WhoTracksMe blog 17 06 2019
+
+
+ Functional JavaScript: Traversing Trees with a Recursive Reduce
+James Sinclair 12 06 2019
+
+
+ Functional JavaScript: Traversing Trees with a Recursive Reduce
+Web Development - James Sinclair 12 06 2019
+
+ 
+
+
+ Exit Condition
+MonkeyUser 11 06 2019
+
+
+ La libertad de desarrollar...: Validando un API rest asíncrono con Cerberus
+Python Hispano 09 06 2019
+Validando un API rest asíncrono con Cerberus
El artículo lo pueden leer en el siguiente enlace
Visiten el blog www.seraph.to
+
+
+ La libertad de desarrollar...: Cómo usar el API de Wikipedia desde Python
+Python Hispano 08 06 2019
+Pueden leer el artículo en el siguiente enlace
Cómo usar el API de Wikipedia desde Python
+
+
+ Improve Serialization Performance in Django Rest Framework
+Haki Benita 07 06 2019
+When a developer chooses Python, Django, or Django Rest Framework, it's usually not because of its blazing fast performance. All of this doesn't mean performance is not important. As this story taught us, major performance boosts can be gained with just a little attention, and a few small changes.
+
+
+ Clojure 1.10.1 release
+Clojure News 06 06 2019
+
+
+
+
+
+
+Clojure 1.10.1 is a small release focusing on two issues: working around a Java performance regression and improving error reporting from clojure.main.
+
+
+Java performance regression
+
+
+
+
+Recent builds of Java 8 (u202), 11 (11.0.2), 12, and 13 included some changes that drastically affect optimization performance of calls from static initializers to static fields. Clojure provides support for loading code on startup from a user.clj file and this occurred in the static initializer of the Clojure runtime (RT) class and was thus affected.
+
+
+This issue may eventually be resolved in Java, but in Clojure we have modified runtime initialization to avoid loading user.clj in a static initializer, which mitigates the case where this caused a performance degradation.
+
+
+clojure.main error reporting
+
+
+
+
+clojure.main is frequently used as a Clojure program launcher by external tools. Previously, uncaught exceptions would be automatically printed by the JVM, which would also print the stack trace.
+
+
+This release will now catch exceptions and use the same error triage and printing functionality as the Clojure repl. The full stack trace, ex-info, and other information will be printed to a target specified by the configuration. See clojure.main docs for configuration details.
+
+
+
+ Changelog
+
+
+
+
+See the change log for a complete list of all changes in Clojure 1.10.1.
+
+
+ May 2019 Monthly Update
+News on Clojurists Together 06 06 2019
+
+
+ Magical, Mystical JavaScript Transducers
+James Sinclair 05 06 2019
+
+
+ Magical, Mystical JavaScript Transducers
+Web Development - James Sinclair 05 06 2019
+
+ 
+
+
+ UI vs UX
+MonkeyUser 04 06 2019
+
+ 
+
+
+ 23 consejos para dar presentaciones técnicas efectivas
+Blog de Diseño Web Vida MRR 03 06 2019
+
¿Has asistido a presentaciones técnicas en público? muchas de ellas aunque por los temas suenas interesantes, la forma en que son expuestas hacen que en ocasiones aburran, se hagan tediosas o largas, o simplemente no aprendas lo que en un principio te están vendiendo que vas a conocer. Estos son algunos tips si vas a hacer una presentación de este tipo, donde debemos cuidar ciertos puntos específicos para atraer al público y que una plática técnica sea una buena experiencia de aprendizaje.
- Explicar antes de empezar de qué va a tratar la presentación
- Asegúrate de entender el lenguaje que maneja tu audiencia
- Explica los acrónimos que uses para poner contexto
- Si necesitas que el público aprenda un concepto específico, repítelo 3 veces de diferentes maneras
- Usa imágenes en tu presentación, evita texto que haga que la gente lo lea primero antes de ponerte atención
- Preséntate y di tu nombre con claridad
- Hila las recomendaciones con historias que argumenten el por qué de la recomendación
- No te limites a un slide
- Si vas a colocar código en una presentación, asegúrate de que tenga el tamaño adecuado para ser leído a la distancia
- Recuerda que tu público es inteligente, pero no es especialista en el tema que tu hablas, procura explicar todos tus puntos claramente
- Pon un resumen al final de tu charla, para volver a recordar los puntos más importantes
- Usa ejemplos y metáforas para explicar conceptos difíciles
- Trata de explicar a tu audiencia por qué a nivel técnico hay mejoras o no, por qué se están haciendo las cosas de otra forma y el beneficio que ellos obtendrán de hacerlo.
- Practica para tener el tiempo suficiente de dar tu plática y tener espacio de preguntas y respuestas
- Haz pausas entre cada explicación de puntos importantes, para que la audiencia pueda entenderlas.
- Haz bromas para llamar la atención de las personas que están distrayéndose, solo si puedes hacerlo.
- Trata de orientar al público no solo en lo que está pasando ahora, sino lo que vendrá en el futuro.
- Usa un tono de voz dinámico, para evitar que la gente se canse o se duerma por un tono de voz bajo y lento.
- Evita dar contexto muy largo del tema que hablas, usa 10 o menos minutos para darle y a continuación entra de lleno en lo más importante que vienes a platicar.
- Crea suspenso y curiosidad desde el inicio de tu plática
- Pon información adicional a videos, posts o lecturas sugeridas para que la gente pueda encontrar más información relacionada.
- Al final de la presentación da las gracias y espera que la gente aplauda. Cuando el presentador no planea espacios para que el público aplauda se crea un momento muy incómodo.
- Practica con alguien que confíes y te pueda dar retroalimentación para que puedas mejorarlo.
+ 
+
+
+ Diferencias entre == y === en Javascript
+Óscar Lijó 30 05 2019
+Veamos cuales son las diferencias entre == y === cuando programamos en Javascript. Mientras que al == se le considera igualdad débil o abstracta, al === se le conoce como igualdad estricta, fuerte o también se le llama identidad. La diferencia es que mientras que con el == antes de hacer la comparación se convierten…
+La entrada Diferencias entre == y === en Javascript aparece primero en Óscar Lijó.
+ +
+
+ Functional JavaScript: Five ways to calculate an average with array reduce
+James Sinclair 30 05 2019
+
+
+ Functional JavaScript: Five ways to calculate an average with array reduce
+Web Development - James Sinclair 30 05 2019
+
+
+ Cestas ecológicas - Grupo de consumo
+Andanzas de una ambientóloga . . . 29 05 2019
+
+ 
+
+
+ Hack Slash Revert
+MonkeyUser 28 05 2019
+
+
+ Pattern Matching in Common Lisp
+Lisp journey 26 05 2019
+New page on the Cookbook: +https://lispcookbook.github.io/cl-cookbook/pattern_matching.html All +examples come from Trivia’s wiki.
+ +The ANSI Common Lisp standard does not include facilities for pattern +matching, but libraries existed for this task and +Trivia became a community +standard.
+ + + +Table of Contents
+ + + + + +For an introduction to the concepts of pattern matching, see Trivia’s wiki.
+ +Trivia matches against a lot of lisp objects and is extensible.
+ +The library is in Quicklisp:
+ +(ql:quickload "trivia")
+For the following examples, let’s use the library:
(use-package :trivia)
+Common destructuring patterns
+ +cons
+
+(match '(1 2 3)
+ ((cons x y)
+ ; ^^ pattern
+ (print x)
+ (print y)))
+;; |-> 1
+;; |-> (2 3)
+list, list*
+
+(match '(something #(0 1 2))
+ ((list a (vector 0 _ b))
+ (values a b)))
+SOMETHING
+2
+list* pattern:
(match '(1 2 . 3)
+ ((list* _ _ x)
+ x))
+3
+Note that using list would match nothing.
vector, vector*
+
+vector checks if the object is a vector, if the lengths are the
+same, and if the contents matches against each subpatterns.
vector* is similar, but called a soft-match variant that allows if
+the length is larger-than-equal to the length of subpatterns.
(match #(1 2 3)
+ ((vector _ x _)
+ x))
+;; -> 2
+(match #(1 2 3 4)
+ ((vector _ x _)
+ x))
+;; -> NIL : does not match
+(match #(1 2 3 4)
+ ((vector* _ x _)
+ x))
+;; -> 2 : soft match.
+<vector-pattern> : vector | simple-vector
+ bit-vector | simple-bit-vector
+ string | simple-string
+ base-string | simple-base-string | sequence
+(<vector-pattern> &rest subpatterns)
+Class and structure pattern
+ +There are three styles that are equivalent:
+ +(defstruct foo bar baz)
+(defvar *x* (make-foo :bar 0 :baz 1)
+
+(match *x*
+ ;; make-instance style
+ ((foo :bar a :baz b)
+ (values a b))
+ ;; with-slots style
+ ((foo (bar a) (baz b))
+ (values a b))
+ ;; slot name style
+ ((foo bar baz)
+ (values bar baz)))
+type, satisfies
+
+The type pattern matches if the object is of type. satisfies matches
+if the predicate returns true for the object. A lambda form is
+acceptable.
assoc, property, alist, plist
+
+All these patterns first check if the pattern is a list. If that is +satisfied, then they obtain the contents, and the value is matched +against the subpattern.
+ +Array, simple-array, row-major-array patterns
+ + + +Logic based patterns
+ +and, or
+
+(match x
+ ((or (list 1 a)
+ (cons a 3))
+ a))
+matches against both (1 2) and (4 . 3) and returns 2 and 4, respectively.
not
+
+It does not match when subpattern matches. The variables used in the +subpattern are not visible in the body.
+ +guards
+
+The syntax is guard + subpattern + a test form, and the body.
(match (list 2 5)
+ ((guard (list x y) ; subpattern
+ (= 10 (* x y)) ; test-form
+ (- x y) (satisfies evenp)) ; generator1, subpattern1
+ t))
+If the subpattern is true, the test form is evaluated, and if it is +true it is matched against subpattern1.
+ +The above returns nil, since (- x y) == 3 does not satisfies evenp.
Nesting patterns
+ +Patterns can be nested:
+ +(match '(:a (3 4) 5)
+ ((list :a (list _ c) _)
+ c))
+returns 4.
See more
+ +See special patterns: place, bind and access.
+
+ Functions Tutorial: Arguments, Multiple Values, funcall and apply, closures and more
+Lisp journey 26 05 2019
+Here’s an enhanced page for the Cookbook: https://lispcookbook.github.io/cl-cookbook/functions.html
+ +Only the Currying part was untouched (we enhanced it already), the +higher-order functions part existed and was rewritten. The rest is +new, and it should help you start writing Common Lisp quicker than +ever.
+ +Happy lisping !
+ + + +Table of Contents
+ +-
+
- Named functions:
defun
+ - Arguments
+
+
-
+
- Base case: required arguments +
- Optional arguments:
&optional
+ - Named parameters:
&key+ +
+ - Return values + + +
- Anonymous functions:
lambda
+ - Calling functions programatically:
funcallandapply
+ - Higher order functions: functions that return functions +
- Closures +
setffunctions
+- Currying + + +
- Documentation +
+
Named functions: defun
+
+Creating named functions is done with the defun keyword. It follows this model:
(defun <name> (list of arguments)
+ "docstring"
+ (function body))
+The return value is the value returned by the last expression of the body +(see below for more). There is no “return xx” statement.
+ +So, for example:
+ +(defun hello-world ()
+ ;; ^^ no arguments
+ (print "hello world!"))
+Call it:
+ +(hello-world)
+;; "hello world!" <-- output
+;; "hello world!" <-- a string is returned.
+Arguments
+ +Base case: required arguments
+ +Add in arguments like this:
+ +(defun hello (name)
+ "Say hello to `name'."
+ (format t "hello ~a !~&" name))
+;; HELLO
+(where ~a is the most used format directive to print a variable
+aesthetically and ~& prints a newline)
Call the function:
+ +(hello "me")
+;; hello me ! <-- this is printed by `format`
+;; NIL <-- return value: `format t` prints a string to standard output and returns nil.
+If you don’t specify the right amount of arguments, you’ll be trapped +into the interactive debugger with an explicit error message:
+ +(hello)
+ +++ +invalid number of arguments: 0
+
Optional arguments: &optional
+
+Optional arguments are declared after the &optional keyword in the
+lambda list. They are ordered, they must appear one after another.
This function:
+ +(defun hello (name &optional age gender) …)
+must be called like this:
+ +(hello "me") ;; a value for the required argument, zero optional arguments
+(hello "me" "7") ;; a value for age
+(hello "me" 7 :h) ;; a value for age and gender
+Named parameters: &key
+
+It is not always convenient to remember the order of the arguments. It
+is thus possible to supply arguments by name: we declare them using
+&key <name>, we set them with :name <value> in the function call,
+and we use name as a regular variable in the function body. They are
+nil by default.
(defun hello (name &key happy)
+ "If `happy' is `t', print a smiley"
+ (format t "hello ~a " name)
+ (when happy
+ (format t ":)~&"))
+The following calls are possible:
+ +(hello "me")
+(hello "me" :happy t)
+(hello "me" :happy nil) ;; useless, equivalent to (hello "me")
+and this is not valid: (hello "me" :happy):
++ +odd number of &KEY arguments
+
A similar example of a function declaration, with several key parameters:
+ +(defun hello (name &key happy lisper cookbook-contributor-p) …)
+it can be called with zero or more key parameters, in any order:
+ +(hello "me" :lisper t)
+(hello "me" :lisper t :happy t)
+(hello "me" :cookbook-contributor-p t :happy t)
+Mixing optional and key parameters
+ +It is generally a style warning, but it is possible.
+ +(defun hello (&optional name &key happy)
+ (format t "hello ~a " name)
+ (when happy
+ (format t ":)~&")))
+In SBCL, this yields:
+ +; in: DEFUN HELLO
+; (SB-INT:NAMED-LAMBDA HELLO
+; (&OPTIONAL NAME &KEY HAPPY)
+; (BLOCK HELLO (FORMAT T "hello ~a " NAME) (WHEN HAPPY (FORMAT T ":)~&"))))
+;
+; caught STYLE-WARNING:
+; &OPTIONAL and &KEY found in the same lambda list: (&OPTIONAL (NAME "John") &KEY
+; HAPPY)
+;
+; compilation unit finished
+; caught 1 STYLE-WARNING condition
+We can call it:
+ +(hello "me" :happy t)
+;; hello me :)
+;; NIL
+Default values
+ +In the lambda list, use pairs to give a default value to an optional or a key argument, like (happy t) below:
(defun hello (name &key (happy t))
+Now happy is true by default.
Variable number of arguments: &rest
+
+Sometimes you want a function to accept a variable number of
+arguments. Use &rest <variable>, where <variable> will be a list.
(defun mean (x &rest numbers)
+ (/ (apply #'+ x numbers)
+ (1+ (length numbers))))
+(mean 1)
+(mean 1 2)
+(mean 1 2 3 4 5)
+&allow-other-keys
+
+Observe:
+ +(defun hello (name &key happy)
+ (format t "hello ~a~&" name))
+
+(hello "me" :lisper t)
+;; => Error: unknown keyword argument
+whereas
+ +(defun hello (name &key happy &allow-other-keys)
+ (format t "hello ~a~&" name))
+
+(hello "me" :lisper t)
+;; hello me
+We might need &allow-other-keys when passing around arguments or
+with higher level manipulation of functions.
Return values
+ +The return value of the function is the value returned by the last +executed form of the body.
+ +There are ways for non-local exits (return-from <function name> <value>), but they are usually not needed.
Common Lisp has also the concept of multiple return values.
+ +Multiple return values: values and multiple-value-bind
+
+Returning multiple values is not like returning a tuple or a list of +results ;) This is a common misconception.
+ +Multiple values are specially useful and powerful because a change in +them needs little to no refactoring.
+ +(defun foo (a b c)
+ a)
+This function returns a.
(defvar *res* (foo :a :b :c))
+;; :A
+We use values to return multiple values:
(defun foo (a b c)
+ (values a b c))
+(setf *res* (foo :a :b :c))
+;; :A
+Observe here that *res* is still :A.
All functions that use the return value of foo need no change, they
+still work. If we had returned a list or an array, this would be
+different.
We destructure multiple values with multiple-value-bind (or
+mvb+TAB in Slime for short):
(multiple-value-bind (res1 res2 res3)
+ (foo :a :b :c)
+ (format t "res1 is ~a, res2 is ~a, res2 is ~a~&" res1 res2 res3))
+;; res1 is A, res2 is B, res2 is C
+;; NIL
+Its general form is
+ +(multiple-value-bind (var-1 .. var-n) expr
+ body)
+The variables var-n are not available outside the scope of multiple-value-bind.
Last but not least: note that (values) with no values returns… no values at all.
See also multiple-value-call.
Anonymous functions: lambda
+
+Anonymous functions are created with lambda:
(lambda (x) (print x))
+We can call a lambda with funcall or apply (see below).
If the first element of an unquoted list is a lambda expression, the +lambda is called:
+ +((lambda (x) (print x)) "hello")
+;; hello
+Calling functions programatically: funcall and apply
+
+funcall is to be used with a known number of arguments, when apply
+can be used on a list, for example from &rest:
(funcall #'+ 1 2)
+(apply #'+ '(1 2))
+Higher order functions: functions that return functions
+ +Writing functions that return functions is simple enough:
+ +(defun adder (n)
+ (lambda (x) (+ x n)))
+;; ADDER
+Here we have defined the function adder which returns an object of type function.
To call the resulting function, we must use funcall or apply:
(adder 5)
+;; #<CLOSURE (LAMBDA (X) :IN ADDER) {100994ACDB}>
+(funcall (adder 5) 3)
+;; 8
+Trying to call it right away leads to an illegal function call:
+ +((adder 3) 5)
+In: (ADDER 3) 5
+ ((ADDER 3) 5)
+Error: Illegal function call.
+Indeed, CL has different namespaces for functions and variables, i.e. the same name can refer to different things depending on its position in a form that’s evaluated.
+ +;; The symbol foo is bound to nothing:
+CL-USER> (boundp 'foo)
+NIL
+CL-USER> (fboundp 'foo)
+NIL
+;; We create a variable:
+CL-USER> (defparameter foo 42)
+FOO
+* foo
+42
+;; Now foo is "bound":
+CL-USER> (boundp 'foo)
+T
+;; but still not as a function:
+CL-USER> (fboundp 'foo)
+NIL
+;; So let's define a function:
+CL-USER> (defun foo (x) (* x x))
+FOO
+;; Now the symbol foo is bound as a function too:
+CL-USER> (fboundp 'foo)
+T
+;; Get the function:
+CL-USER> (function foo)
+#<FUNCTION FOO>
+;; and the shorthand notation:
+* #'foo
+#<FUNCTION FOO>
+;; We call it:
+(funcall (function adder) 5)
+#<CLOSURE (LAMBDA (X) :IN ADDER) {100991761B}>
+;; and call the lambda:
+(funcall (funcall (function adder) 5) 3)
+8
+To simplify a bit, you can think of each symbol in CL having (at least) two “cells” in which information is stored. One cell - sometimes referred to as its value cell - can hold a value that is bound to this symbol, and you can use boundp to test whether the symbol is bound to a value (in the global environment). You can access the value cell of a symbol with symbol-value.
The other cell - sometimes referred to as its function cell - can hold the definition of the symbol’s (global) function binding. In this case, the symbol is said to be fbound to this definition. You can use fboundp to test whether a symbol is fbound. You can access the function cell of a symbol (in the global environment) with symbol-function.
Now, if a symbol is evaluated, it is treated as a variable in that its value cell is returned (just foo). If a compound form, i.e. a cons, is evaluated and its car is a symbol, then the function cell of this symbol is used (as in (foo 3)).
In Common Lisp, as opposed to Scheme, it is not possible that the car of the compound form to be evaluated is an arbitrary form. If it is not a symbol, it must be a lambda expression, which looks like (lambdalambda-list form*).
This explains the error message we got above - (adder 3) is neither a symbol nor a lambda expression.
If we want to be able to use the symbol *my-fun* in the car of a compound form, we have to explicitely store something in its function cell (which is normally done for us by the macro defun):
;;; continued from above
+CL-USER> (fboundp '*my-fun*)
+NIL
+CL-USER> (setf (symbol-function '*my-fun*) (adder 3))
+#<CLOSURE (LAMBDA (X) :IN ADDER) {10099A5EFB}>
+CL-USER> (fboundp '*my-fun*)
+T
+CL-USER> (*my-fun* 5)
+8
+Read the CLHS section about form evaluation for more.
+ +Closures
+ +Closures allow to capture lexical bindings:
+ +(let ((limit 3)
+ (counter -1))
+ (defun my-counter ()
+ (if (< counter limit)
+ (incf counter)
+ (setf counter 0))))
+
+(my-counter)
+0
+(my-counter)
+1
+(my-counter)
+2
+(my-counter)
+3
+(my-counter)
+0
+Or similarly:
+ +(defun repeater (n)
+ (let ((counter -1))
+ (lambda ()
+ (if (< counter n)
+ (incf counter)
+ (setf counter 0)))))
+
+(defparameter *my-repeater* (repeater 3))
+;; *MY-REPEATER*
+(funcall *my-repeater*)
+0
+(funcall *my-repeater*)
+1
+(funcall *my-repeater*)
+2
+(funcall *my-repeater*)
+3
+(funcall *my-repeater*)
+0
+See more on Practical Common Lisp.
+ +setf functions
+
+A function name can also be a list of two symbols with setf as the
+first one, and where the first argument is the new value:
(defun (setf <name>) (new-value <other arguments>)
+ body)
+This mechanism is particularly used for CLOS methods.
+ +A silly example:
+ +(defparameter *current-name* ""
+ "A global name.")
+
+(defun hello (name)
+ (format t "hello ~a~&" name))
+
+(defun (setf hello) (new-value)
+ (hello new-value)
+ (setf *current-name* new-value)
+ (format t "current name is now ~a~&" new-value))
+
+(setf (hello) "Alice")
+;; hello Alice
+;; current name is now Alice
+;; NIL
+Currying
+ +Concept
+ +A related concept is that of currying which you might be familiar with if you’re coming from a functional language. After we’ve read the last section that’s rather easy to implement:
+ +CL-USER> (declaim (ftype (function (function &rest t) function) curry) (inline curry))
+NIL
+CL-USER> (defun curry (function &rest args)
+ (lambda (&rest more-args)
+ (apply function (append args more-args))))
+CURRY
+CL-USER> (funcall (curry #'+ 3) 5)
+8
+CL-USER> (funcall (curry #'+ 3) 6)
+9
+CL-USER> (setf (symbol-function 'power-of-ten) (curry #'expt 10))
+#<Interpreted Function "LAMBDA (FUNCTION &REST ARGS)" {482DB969}>
+CL-USER> (power-of-ten 3)
+1000
+Note that the declaim statement above is just a hint for the compiler so it can produce more efficient code if it so wishes. Leaving it out won’t change the semantics of the function.
With the Alexandria library
+ +Now that you know how to do it, you may appreciate using the +implementation of the +Alexandria +library (in Quicklisp).
+ +(ql:quickload :alexandria)
+
+(defun adder (foo bar)
+ "Add the two arguments."
+ (+ foo bar))
+
+(defvar add-one (alexandria:curry #'adder 1) "Add 1 to the argument.")
+
+(funcall add-one 10) ;; => 11
+
+(setf (symbol-function 'add-one) add-one)
+(add-one 10) ;; => 11
+Documentation
+ +-
+
- functions: http://www.lispworks.com/documentation/HyperSpec/Body/t_fn.htm#function +
- ordinary lambda lists: http://www.lispworks.com/documentation/HyperSpec/Body/03_da.htm +
- multiple-value-bind: http://clhs.lisp.se/Body/m_multip.htm +
+
+ Functional JavaScript: How to use array reduce for more than just numbers
+James Sinclair 22 05 2019
+
+
+ Functional JavaScript: How to use array reduce for more than just numbers
+Web Development - James Sinclair 22 05 2019
+
+
+ Creating an emacs formatter the easy way
+(ノ°Д°）ノ︵ ┻━┻ 21 05 2019
+
+
+ Creating an emacs formatter the easy way
+(ノ°Д°）ノ︵ ┻━┻ 21 05 2019
++Some weeks ago I discovered a really nice package for emacs called reformatter.el. This package allows to define reformat functions in a easy way.
+
+Most languages have a reformat tool. Elixir has mix format, Elm has elm format, python has black and so on. These formatters are convenient because they give uniformity to the code, but this is a topic for another post.
+Having these formatters integrated within our favorite editor is great. These are enough(at least for me) reasons to use reformatter.el so let's get into the code:
+reformatter.el has a simple macro that allows us to define a formatter with just a few lines.
+For this example we'll create a formatter for haskell using hindent 1.
+
+
+(reformatter-define haskell-format
+ :program "hindent")
+We just need to define the command that will be used to format the code. In this case hindent. This will create some useful functions:
-
+
-
+
haskell-format
+
+ -
+
haskell-format-buffer
+
+ -
+
haskell-format-region
+
+ -
+
haskell-format-on-save-mode
+
+
These functions can be used with a key-binding:
+
+
+
+(define-key haskell-mode-map (kbd "C-c C-f") 'haskell-format-buffer)
+Also we can setup emacs to run the formatter when the file is saved, for example put this code in your .dir-locals.el and it will do the work.
+
+
+(haskell-mode (mode . haskell-format-on-save))
+The program used to format our code needs to be able to read from stdin and return the formatted code to stdout. In this case hindent does it by default.
+In some cases the formatter doesn't do this by default. For those cases we can pass extra arguments to the command using :args key in the formatter macro. For example elixir format receive a file or a pattern by default but we can change that using mix format -, now it will read from stdin, so we need to pass these parameters to our formatter. The code should be:
+
+
+(reformatter-define elixir-format
+ :program "mix"
+ :args '("format" "-"))+Now it will work properly.
+
+This package is very useful if you don't want to install a external package just for formatting. I replaced hindent-mode (haskell formatter) and a custom elixir formatter with this package. Also this package is used in elm-mode package.
+
+
+
+ +
+
+
+
+
+ I Now Work Professionally in Common Lisp O_o
+Lisp journey 20 05 2019
+I’ve been paid to work on Common Lisp projects for a company for three +months already. I didn’t expect it :) And we did hire !
+ +My Github profile shows a good part of what my experience is. I am a +regular “full stack developper”, with 7 years of professional +experience. I worked on diverse Python and Javascript projects for +huge to small companies, private and public. When I re-discovered +Common Lisp, I saw it solved a lot of problems I had developing and +deploying medium to large software, and it promised to solve all of +them (we’re nearly there :D ). I started to write about my experience +on this blog and I contributed to open source projects, of which a lot +of documentation effort. It is this public activity that drew the +attention of the guys at Atlas, who +contacted me, without a job announce. We developed and we maintain +a proprietary and successful web application that paid the bills, in +Common Lisp of course, and we work hard on other projects, such as the +Next browser.
+ +So, I can only encourage you to start a Common Lisp project, to come +enhance libraries and documentation and to write about it ! There are +few official job announces, some are posted on reddit, and some jobs +just won’t have a public announce. You’d better be ready.
+ +For the curious, our web app is rather classic, it uses the Caveman +web framework and is deployed on DigitalOcean. We do deploy with zero +downtime, as CL permits, for trivial updates (we are more cautious +otherwise). I’ll post its name in the comments if/when I know I can.
+ +Happy lisping.
+ +
+
+ Folding the DOM
+Josh Comeau's blog 19 05 2019
+
+
+ JIRA Migration
+Clojure News 16 05 2019
+
+
+
+
+
+
+Clojure has been very fortunate to receive infrastructure support from Atlassian (for JIRA and Confluence) and Contegix (for hosting) for many years. The Confluence and JIRA instances were not kept up to date, and have grown increasingly hard to maintain. Recently, we decided to shut down Confluence (content was either moved to clojure.org or archived) and we are now preparing to migrate from our old JIRA instance into a new cloud-hosted instance. Many thanks to Atlassian again for supporting our efforts in this.
+
+
+User migration
+
+
+
+
+Due to the large number of users, it is not feasible for us to move everyone, and we’ve decided to migrate all users that have edited tickets in the past (changed a description, added a patch, etc) - this will move user names and emails, not passwords. When the import happens, email invites will go out for users in the new system based on the email address in the old system. Initially these users will not have access to projects.
+
+
+Users that created or commented on tickets in the past (but did not edit) will not automatically be migrated. We are planning to leverage JIRA Service Desk to create a new path for language users to file tickets without needing an account. These incoming tickets can be triaged and turned into JIRA tickets as needed. We are also looking at a new process to obtain a contributor account and gain access to the system for commenting or other work. Stay tuned for more on that.
+
+
+
+ Backup and import
+
+
+
+
+After users have been loaded, a backup of the old system and import into the new system will occur. All projects, issues, attachments, comments, etc will be preserved. This will be done on a per-project basis until the migration is complete and might take a while to fully import and verify.
+
+
+After that, there will be some work to enable access for different project administrators and users before the system is fully available.
+
+
+We will put the old system into a read-only mode once the backup and import has started. Once the import is complete, the old system will be shut down. Redirect rules will be set up for the old Confluence and JIRA urls to point to the new Confluence archive and new JIRA system so that old links will continue to work.
+
+
+Please be patient as we make the transition. Thanks!
+
+
+ April 2019 Monthly Update
+News on Clojurists Together 16 05 2019
+
+
+ Elegant error handling with the JavaScript Either Monad
+James Sinclair 15 05 2019
+
+
+ Elegant error handling with the JavaScript Either Monad
+Web Development - James Sinclair 15 05 2019
+
+ 
+
+
+ Java no es gratuito
+Blog de Diseño Web Vida MRR 14 05 2019
+
Java ha evolucionado a un paso siempre desigual con cada versión, lo que hace que sea odiado y amado por la comunidad de desarrolladores. El otro tema que tiene Java es que Oracle es el dueño del lenguaje, y aunque sigue siendo Open Source, tiene sus propias restricciones para poder usarlo. En este video les explico por qué Java no es gratuito en una parte importante de sus componentes, ya que es importante saberlo para poder crear aplicaciones con otras necesidades y aplicaciones.
+ 
+
+ 
+
+
+ everythingyoudosuckscon.io
+MonkeyUser 14 05 2019
+
+ 
+
+
+ ¿Cómo elegir cuál lenguaje de programación aprender ?
+Blog de Diseño Web Vida MRR 13 05 2019
+ |
Si estás buscando razones para poder empezar con un lenguaje de programación, este post te va a interesar. Te voy a comentar algunas razones por las cuales es mejor empezar en el mundo del desarrollo con algunos lenguajes y después con otros.
Lenguajes de propósito común
Los lenguajes de propósito común son aquellos que no están orientados a un tema específico. Los puedes usar para hacer aplicaciones web, sistemas, aplicaciones con interfaz gráfica, etc, por lo que aprender uno de estos facilita la aplicación a varias utilidades.
Python: es uno de los lenguajes más fáciles para empezar con programación. Su sintaxis también es muy simple, por lo que puedes entender bien cómo va funcionando el código y las estructuras, además de que Python poco a poco se convierte en el lenguaje preferido para la gente que empieza con programación.
Javascript: es un real competidor a sentarse en el trono de los lenguajes favoritos para empezar. Javascript ha evolucionado de forma impresionante en unos pocos años para poder ser utilizado en cualquier plataforma y ecosistema presente hoy en día. No hay nada que no se pueda hacer con Javscript, y como menciono, su evolución va avanzando de forma increíblemente rápida, pero obviamente si lo que quieres es tener un enfoque un poco más web, este lenguaje te puede ayudar mucho.
Ruby: es un lenguaje con la característica de que tiene soporte de muchos paradigmas de programación, como la lineal, la orientada a objetos y funcional. Su sintaxis es más parecido a una estructura de conversación que los anteriores, y te dejará compilar el código aunque tenga errores, por lo que es bastante amigable para poder empezar.
Java: es el lenguaje que más gustos divide a los programadores. Para muchos ya es un lenguaje que no ha evolucionado de la misma forma que los demás, pero otros creen que es de los lenguajes más maduros. La realidad es que si quieres iniciar con un lenguaje que te explique de forma muy visual la programación orientada a objetos este es el mejor. Aprender Java es fácil, quizá verás que tiene mucho código para hacer cosas sencillas, pero también hay una razón para ello, y si logras entender ese concepto prácticamente Java lo dominas en unas cuentas semanas.
Lenguajes de propósito específico
Si queremos aprender algo específico podemos usar de referencia algunos de los siguientes lenguajes para empezar por ese camino:
Machine Learning: los dos más populares son Python y R, lenguajes que por su simpleza en el código son más eficientes para realizar cálculos estadísticos.
Desarrollo móvil: para desarrollar aplicaciones móviles nativas tenemos Swift para iOS y Java y Kotlin para Android. Kotlin especialmente toma mucha referencia de Java y le quita el código que no es necesario, por lo que también es buen candidato para hacer apps sin siquiera saber programar.
Startups: si tu enfoque es construir algo rápido y funcional Ruby tiene esa ventaja. Ruby es muy usado en empresas que empiezan por la flexibilidad de construir aplicaciones de forma muy rápida y que pueden seguir programando sobre la marcha.
Lenguajes que tienes que evitar al empezar
Si bien hay lenguajes muy populares hoy en día, mi recomendación es evitarlos ya que o cumplen un propósito demasiado específico, que quizá ni siquiera te interese usar, o tienen una complejidad más elevada para aprender, por lo que puede que te desilusionen si decides elegir uno de ellos.
Entre los ejemplos está Go, Scala, Perl, Typescript, C++. Typescript especialmente le agrega complejidad a Javascript, y se entiende que para llegar ahí, entiendes cómo funciona Javascript y las deficiencias que tiene por las que tienes que cubrir con Typescript. C++ es en definitiva la opción si lo que quieres es administrar memoria y objetos de forma detallada y completa en un lenguaje de programación.
+ 
+
+
+ Hacer una PWA con Angular
+Óscar Lijó 08 05 2019
+Hoy en día se hace mucho hincapié en las aplicaciones web progresivas o PWA, hoy voy a explicar como hacer una PWA con Angular. En primer lugar, por si no has escuchado hablar nunca de lo que son las PWA y las ventajas que tienen, voy a hablar un poco de ellas. ¿Qué es una…
+La entrada Hacer una PWA con Angular aparece primero en Óscar Lijó.
+ +
+
+ How to run async JavaScript functions in sequence or parallel
+James Sinclair 08 05 2019
+
+
+ How to run async JavaScript functions in sequence or parallel
+Web Development - James Sinclair 08 05 2019
+
+ 
+
+
+ Deja vu
+MonkeyUser 07 05 2019
+
+
+ How to Let Google Know of Other Languages in Your Django Site
+Haki Benita 06 05 2019
+If you have a public facing Django site in multiple languages, you probably want to let Google and other search engines know about it.
+
+ 
+
+
+ 10 principios de diseño para POO
+Blog de Diseño Web Vida MRR 06 05 2019
+En este post les comparto los 10 principios de diseño para la programación orientada a objetos, esperando que les sirva para mejorar la forma en que hacen código y lo usan.
1. DRY (Don't repeat yourself)
El principio de la POO es la de no repetir el código, hacer código reusable y abstracto, para que puedas usarlo de nuevo sin necesidad de volver a escribir desde cero. Si tu código es imposible de reusarlo en otra aplicación, o tienes que programar ciertas partes de nuevo porque no se puede adecuar, es un síntoma de que necesitas hacer funciones más abstractas, más genéricas para que puedan ser extendidas con requerimientos más puntuales.
2. Encapusla
No hay mucha gente que entienda la importancia de la encapsulación, pero es muy simple. Aprende a encapsular el alcance de tus clases. La forma más fácil de hacerlo es poniendo privadas las variables y métodos que son exclusivos de tu clase, y poniendo públicos los métodos que pueden ser usados por otros objetos. Hay más formas de encapsular el código, pero esos dos son los básicos.
3. Principio de diseño abierto-cerrado
Este principio dice que las clases, métodos y funciones deben estar abiertos para extender su funcionalidad, pero cerrados para ser modificados. Esto significa que tu código debería ser modificado casi nunca pero sí debería servir como base para extenderlo, es decir, para usar herencia, para usar interfaces, para ser la base de nuevas clases, a fin de que nunca llegues a modificar tu código existente para crear nuevo, sino crear código sobre la base que ya tienes.
Esto podemos verlo como si fuera una caja negra, donde tu debes hacer que tu código sea imposible de modificar y solo pueda ser usado desde sus métodos públicos para poder ser extendido.
4. Principio de responsabilidad única
Este principio hace referencia a que nuestras clases y métodos deben tener una sola tarea o actividad. Una clase que se encarga de operar datos no debería administrar componentes gráficos, ni un método que tiene que mandar un correo electrónico debería manejar funciones adicionales. Esto hace que tus funciones cumplan un solo propósito y hace más fácil que las puedas utilizar más adelante.
5. Inyección de dependencias
Las dependencias es cuando en una clase necesitas otra para poder trabajar. Piensa en una clase que toma como base otra para mandar un mensaje de texto. La clase original tiene una dependencia y si quisieras usar esa clase pero no quisieras mandar un mensaje de texto hace que tengas que modificar el código para ello. La mejor forma de resolver un problema así es a través de la inyección de dependencias en donde en vez que que la clase original mande a llamar a la segunda clase, se le inyecte a través del uso de frameworks o interfaces para mandar a llamar a algo que después tiene que ser completado, y de esa forma no dependa de otras clases.
6. Composición sobre herencia
La composición es justamente lo opuesto a la herencia, que es mandar a llamar objetos en vez de heredarlos. Esto es bueno en la medida en que a partir de una misma relación en vez de estar heredando clases y hacer una jerarquía grande, muchas veces para simplificar trabajar con objetos de una misma base en mejor hacerlo a través de la composición o creación de objetos. Para saber más sobre composición y asociación pueden leer este artículo.
7. Principio de sustitución Liskov
Este principio dice que si tienes un objeto de subtipo S que deriva de un tipo T deberías tener la posibilidad de usar el objeto de tipo T de la misma forma que uses al subtipo S. Como ejemplo, tenemos que un objeto de tipo Perro deriva de un objeto de tipo Animal, y si tienes una función que necesita un tipo Perro como parámetro, si colocas un objeto de tipo Animal debería funcionar la clase de la misma forma, sin errores.
8. Principio de segregación de interfaces
Este principio refiere a que no incluyamos métodos que no va a utilizar el programador en una interfaz. Cuando creamos interfaces podemos colorcar métodos que queremos que el programador use para extender su código, pero si metemos funciones que no va a usar o no siempre va a usar, estamos cayendo en este error de POO.
9. Programación de interfaces no implementaciones
Tu código siempre debe estar enfocado a definir interfaces, no implementación de las mismas. Las interfaces ya nos dan una forma abstracta de poder hacer funciones genéricas que puedan ser usadas en muchos escenarios. Hay que mantener esa estrategia para crear código que puedas reusar.
10. Principios de delegación
Este último principio dice que no hay que hacer todo el código nosotros, ya hay clases a las que le podemos delegar esa tarea, como por ejemplo comparar dos objetos. Todos los objetos tienen la clase equals() por lo cual es innecesario implementar un nuevo método para esa funcionalidad. Es un ejemplo básico pero nos dice que hay que conocer los métodos de los objetos para saber qué ya hay código hecho que podemos usar y no todo a fuerza lo tenemos que implementar desde cero.
+ 
+
+
+ End of Year Review 2018-19
+Blogs on Tom Spencer 04 05 2019
+
+
+ End of Year Review 2018-19
+Blogs on Tom Spencer 04 05 2019
+
+
+ Q2 2019 Funding Announcement
+News on Clojurists Together 30 04 2019
+
+ 
+
+
+ Bug Free
+MonkeyUser 30 04 2019
+
+
+
+
+ A quantum bug in Firefox Quantum
+WhoTracksMe blog 29 04 2019
+
+ 
+
+
+ Curiosity
+MonkeyUser 23 04 2019
+
+
+ March 2019 Monthly Update
+News on Clojurists Together 18 04 2019
+
+ 
+
+
+ 7 consejos para crear logotipos en 2019
+Blog de Diseño Web Vida MRR 16 04 2019
+
Parte 1: No olvides los fundamentos
- Conoce tu marca: siempre recuerda que el logotipo debe representar a tu marca, identificarse y ser único. Al final tu marca y logotipo deben transmitir el mismo mensaje
- Obten inspiración: busca nuevas formas, colores y mensajes, no te bases solo en las tendencias o en lo que todos están implementando justo ahora. Crea algo que sea moderno sin tener que ser repetitivo o parecido a algo que ya se ha visto antes.
- Inicia un tablero de humor: usa servicios como Pinterest para empezar a ver imágenes de diferentes logotipos, tratando de identificar lo que te gusta de cada uno de ellos, y de ahí partir para crear algo adecuado para ti.
- Investiga tu audiencia: identifica para quién es ese logotipo. No todos los logotipos funcionan para todas las personas, así que identifica qué tipo de personas verían tu logo y sentirían lo mismo que tu, y que otras a lo mejor pueden interpretar otro mensaje que quizá necesites corregir.
Parte 2: 7 tips para crear logotipos excelente
- Identifica el tipo de logo: los hay desde solo poner tipografía, hasta colocar mascotas o formas identificables
- Escoge una esquema de colores: usa colores que coincidan con tu marca y las sensaciones que transmite. No todos deben ser colores vivos, también puedes usar esquema de grises o blanco y negro.
- Identifica un tipo de fuente: tanto las serifas o sin serifas o las personalizadas son importantes para dar más elegancia o más soltura al mensaje que das en el logo
- Haz un logo único: es imposible crear un logo que no se base en algo ya existente, pero trata que incluso tomando elementos que ya se han visto antes parezca nuevo.
- ¿Cómo están desempeñándose otros diseños?: hay logotipos con doble mensaje en el diseño, o que tienen un toque característico que los diferencia muy claramente. Aprende a identificar qué es lo que caracteriza a un buen logo existente y de ahí parte para darle autenticidad al tuyo.
- Manténlo simple y flexible: no te enredes tanto, siempre lo más simple va a ser lo mejor, pero trata de que se pueda adaptar a nuevos formatos y se vea fresco con el paso de los años.
- Publica tu trabajo pero no esperes un éxito instantáneo: el éxito de un logo no depende de que sea admirado al instante, sino que empiece a ser reconocido a lo largo del tiempo, así que no te limites en medir el éxito de tu logo al instante.
+ 
+
+ 
+
+
+ Conflict Management
+MonkeyUser 16 04 2019
+
+ 
+
+
+ Comparando frameworks para front-end
+Blog de Diseño Web Vida MRR 15 04 2019
+
Me encuentro este interesantísimo artículo de FreeCodeCamp, en el cual comparan la velocidad y tamaño de algunos de los frameworks más famosos que hay para front-end. Si bien cada uno de ellos está enfocado en dar un resultado más o menos parecido, creo que muchos se han preguntado si estos frameworks son realmente un alivio para la gente que diseña aplicaciones web, o solo es un sobre costo que se añade por el hecho de tener un código más ordenado y con posibilidades de mantenerlo mejor.
El análisis que les presento muestra algunas estadísticas que el autor tomó para medir el impacto de cada framework. En primer lugar el construyó la misma aplicación para los siguientes frameworks:
Después de eso empezó con sus métricas.
Rendimiento
Es quizá el punto más importante para todos. De nada sirve tener un framework si el rendimiento del mismo se ve afectado. Siempre hay que tener en cuenta que el rendimiento más óptimo debería ser el poder crear nuestras aplicaciones sin necesidad de un framework. Si acudimos a ellos es porque deberíamos suponer que mucho del tunning de ese rendimiento ya lo trabaja ese framework. El resultado es como sigue:
La mayoría de los frameworks corren por arriba de los 90 puntos, eso quiere decir que prácticamente en cuanto carga tu sitio o aplicación web, también lo hace el framework y sus componentes, a excepción de AngularJS que tiene el desempeño más bajo.
Tamaño
El tamaño es la cantidad de kb que tiene que transferirse para poder cargar tu aplicación web. Entre más grande sea mayor va a ser el tiempo de carga.
Mientras que hay frameworks que solo tienen 9kb de transferencia, hay otros como AngularJS que transfieren hasta 300kb. Esto en perspectiva podría parecer muchísimo, pero también dependiendo de la calidad de la conexión a internet es que se afecta mucho más esa transferencia.
Líneas de código
Las líneas de código es de los parámetros más importantes para un desarrollador. No tiene sentido que tengas que tener más líneas de código solo por usar un framework, si el objetivo inicial es justo simplificar ese proceso de creación con menos líneas.
En la imagen podemos ver que mientras para re-frame un proyecto requirió de 968 líneas de código, el mismo en Angular con ngrx y nx requirió 4,210 líneas de código, es decir, poco más de 4 veces, entonces aunque mucho código lo podrías generar y otro hacerlo tu, la realidad es que se entiende que más líneas de código podría aumentar el tamaño de tu proyecto, y en consecuencia hacerlo un poco más pesado.
Conclusión
Como mencionan en el artículo, no es muy fácil hacer comparaciones de peras con peras y manzanas con manzanas. Es importante notar que podría haber un sesgo pero los datos nos revelan mucha información. Lo que más me sorprende de esas gráficas es que por ejemplo, Vue, React y Angular, a pesar de que son los frameworks más usados, no son ni los más rápidos ni los más pequeños. Hay frameworks que son más ligeros, y si te interesa usar uno pero te interesa cuidar estas tres métricas la respuesta es que puedes optar por utilizar uno diferente a los 3 más populares.
+ 
+
+
+ How do you compose JavaScript functions with multiple parameters?
+James Sinclair 15 04 2019
+
+
+ How do you compose JavaScript functions with multiple parameters?
+Web Development - James Sinclair 15 04 2019
+
+
+ How to Create an Index in Django Without Downtime
+Haki Benita 09 04 2019
+If you ever had to maintain a traffic heavy Django site, you probably had to deal with graceful migrations. In the article I explain what atomic and reversible migrations are, how to execute "raw" SQL in migrations the right way, and how using a little known migration command we can completely alter the Django migrations built-in behavior.
+
+
+ Lazy loading nativo
+Óscar Lijó 09 04 2019
+Haciéndome eco de la reciente publicación de Addy Osmani en su blog, nos encontramos con que dentro de poco el Chrome va a implementar una manera de conseguir hacer lazy loading nativo. Esta es una noticia fantástica. Pero el notición sería que el atributo que van a usar fuera recogido por el estándar de HTML…
+La entrada Lazy loading nativo aparece primero en Óscar Lijó.
+ +
+ 
+
+
+ Code Review
+MonkeyUser 09 04 2019
+
+ 
+
+
+ 11 Trucos para la consola de Javascript de Google Chrome
+Blog de Diseño Web Vida MRR 08 04 2019
+ |
La consola de Google Chrome tiene muchas funcionalidades que nos pueden ayudar de forma muy interesante en nuestro debugging. En este post les presento algunos de los trucos más interesantes que seguramente les van a servir la próxima vez que tengan que desarrollar una aplicación con Javascript.
Estilizar mensajes de consola
Por defecto en la consola de Chrome los mensajes aparecen sin formato, pero si lo que necesitas es tener estilos para diferenciar ciertos mensajes basta con ingresar '%c' al inicio del mensaje de un console.log y colocar como un parámetro adicional los estilos CSS que quieres poner.
Mostrar JSON como tabla
De forma sencilla podemos mostrar un JSON en formato de tabla con el siguiente script:
Obtener las llaves de un arreglo
Dado un arreglo se pueden extraer las llaves o claves de la siguiente forma:
Obtener el elemento seleccionado
Podemos hacer referencia al elemento HTML seleccionado con el símbolo $0, y poder navegar por el historico de elementos seleccionados con $1, $2,etc
Referenciar objetos HTML
Tradicionalmente usamos document.getElementById() o querySelector() para hacer referencia a objetos. En la consola de Chrome podemos hacer referencia usando la simbología de $('selector'), muy parecido a como se hace con jQuery, pero esta es una forma nativa de hacerlo en la consola de Chrome.
Obtener eventos configurados en elemento HTML
Se pueden ver de forma sencilla los eventos configurados en un elemento HTML así:
Monitorear todos los eventos sobre un elemento HTML
Se pueden monitorear todos los eventos sobre un elemento específico, usando dos comandos: monitorEvents() y unmonitorEvents()
Medir tiempo de ejecución de un procedimiento
Puedes calcular el tiempo que tarda un procedimiento en ejecutarse usando dos funciones: console.time() y console.timeEnd()
Mostrar todas las propiedades de un elemento HTML
Usando la función dir(selector) se puede mostrar todo lo que contiene un elemento HTML
Hacer referencia a la última expresión resultante
La última expresión en la consola también puede asignarse a una variable $_ la cual siempre tendrá el valor más reciente calculado dentro de la misma.
+ 
+
+
+ Hyperreals *R: Mutabilidad de Listas
+Python Hispano 07 04 2019
+
+
+Info
+Puedes visionar este artículo y descargártelo como notebook ipython en http://nbviewer.jupyter.org/5177340
+Mucha gente, cuando se enfrenta por primera vez al lenguaje python, no entiende bien el concepto de “inmutabilidad” que tanto repite la documentación al tratar de diferenciar algunos tipos contenedores como tuplas, listas, conjuntos y diccionarios.
+Por lo general, la gente formada en lenguajes de programación clásicos tiene la idea de que las variables son porciones de memoria donde colocar valores. Que una variable no se éso, variable, resulta un contrasentido. Han visto constantes, pero sólo sirven para inicializar variables y poco más. Si en su carrera hubieran sido formados en algún lenguaje funcional se darían cuenta que hay quienes piensan que las variables que cambian de valor son las raras, que lo más natural es que una variable conserve su valor inicial, o sea, que sea inmutable.
+Por poner un ejemplo, el siguiente código está basado en una pregunta reciente en la lista python-es. Tenemos una lista de pares y queremos quitar las parejas repetidas con orden cambiado:
+def quitar_dup(lista):
+
+ for item in lista:
+
+ item.reverse()
+
+ if item in lista:
+ lista.remove(item)
+
+ return lista
+
+L=[[1, 2], [1, 3], [2, 1], [3, 1]]
+
+print quitar_dup(L) #res: [[1, 3], [3, 1]]
+A simple vista, el código parece correcto, pero tenemos dos operaciones que pueden mutar listas: .reverse() y .remove(). De hecho, el resultado es incorrecto: [[1, 3], [3, 1]]
A medida que recorremos la lista en el bucle for, la lista se va modificando, lo que da lugar a resultados inesperados. Si no lo ves bien, basta añadir algunos prints en lugares estratégicos para que comprobar lo que pasa. De hecho, sólo existen dos iteraciones para cuatro elementos que tiene la lista.
Otro tipo de casos son cuando pasamos listas a funciones:
+>>> def add(a, l):
+... if a not in l:
+... l += [a]
+... return l
+...
+>>> L = [1, 2, 3]
+>>> add(1, L)
+[1, 2, 3]
+>>> add(4, L)
+[1, 2, 3, 4]
+>>> L
+[1, 2, 3, 4]
+Como efecto colateral, la función ha modificado la lista pasada como argumento, algo que no es siempre deseable. El problema se agrava más si empleamos listas en valores por defecto:
+>>> def add(a, l=[]):
+... if a not in l:
+... l += [a]
+... return l
+...
+>>> add(1)
+[1]
+>>> add(2)
+[1, 2]
+>>> add(3, [])
+[3]
+>>> add(4)
+[1, 2, 4]
+Como se puede ver, aunque intentemos resetear el valor por defecto, la función tiene un efecto memoria que es imposible de eliminar. Este efecto es a veces buscado, pero en general debe ser siempre evitado ya que desvirtúa el sentido que tiene dar valores por defecto.
+Estos efectos son todavía más perniciosos con la funciones lambda. Al carecer de una clausura como las funciones, la evaluación de una función lambda depende del scope donde han sido definidas. Por ejemplo, observa esta creación de una lista de funciones:
+fns = []
+
+for i in range(5):
+ fns.append( lambda x: x + i)
+
+print fns[1](10)
+print fns[2](10)
+Siempre añade 4 al argumento, que es el valor de i al acabar el bucle, independientemente de qué valor tenía esta variable en el momento de crear la función lambda. No es de extrañar que se recomiende dejar de usar estas funciones.
Por último, otro efecto funesto de la mutabilidad de las listas aparece en la creación de listas multidimensionales (aka matrices). Una forma rápida de crear una matriz de 2x2 es: [[0]*2]*2. El problema aquí está en que cuando clonamos listas, en lugar de copiar los elementos, los enlaza entre sí. Quizás se vea mejor si hacemos alguna operación:
>>> l = [[0]*2]*2
+[[0, 0], [0, 0]]
+>>> l[0][0]
+0
+>>> l[0][0] = 1
+>>> l
+[[1, 0], [1, 0]]
+>>> l[0] is l[1]
+True
+Los elementos l[0] y l[1] son el mismo elemento. Que los elementos de una lista puedan estar entrelazados resulta muy interante para algunos algoritmos de búsquedas. Pero hay que conocer bien lo que estamos haciendo si no queremos llevarnos alguna sorpresa.
Recomendaciones para hacer código funcional
+Copia de listas
+En funciones y métodos, si recibimos una lista como argumento, la primera acción defensiva que deberíamos hacer es copiar la lista en una variable local y trabajar solo con la variable local desde ese momento. Con una asignación directa no se realiza una copia, más bien estaríamos enlazando una nueva referenciasin solucionar nada.
+La forma consensuada entre programadores python de copiar una lista es con la operación de spliting L[:], aunque sirven otras operaciones idempotentes como L*1 ó L+[]1. Para listas de elementos entrelazados tendremos que acudir a otros mecanismos de copia como los que ofrece el módulo copy, aunque no será frecuente que lo necesitemos.
def add(a, lista):
+ l = lista[:]
+ if a not in l:
+ l += [a]
+ return l
+En cuanto a los argumentos por defecto, lo mejor es no usar nunca una lista para tal cosa. Una buena estrategia defensiva consiste en usar None de esta forma:
def add(a, lista=None):
+ l = [] if lista is None else lista[:]
+ if a not in l:
+ l += [a]
+ return l
+Operaciones inmutables con listas
+En cuanto a evitar las operaciones que mutan listas, siempre hay alternativas inmutables de todas estas operaciones. El siguiente cuadro puede servir como referencia:
+| Mutable | +Inmutable | +
|---|---|
L.append(item) |
+L+[item] |
+
L.extend(sequence) |
+L + list(sequence) |
+
L.insert(index, item) |
+L[:index] + [item] + L[index:] |
+
L.reverse() |
+L[::-1] |
+
L.sort() |
+sorted(L) |
+
item = L.pop() |
+item,L = L[-1],L[:-1] |
+
item = L.pop(0) |
+item,L = L[0],L[1:] |
+
item = L.pop(index) |
+item, L = L[item], L[:item]+L[item+1:] |
+
L.remove(item) |
+L=L[:item]+L[item+1:] |
+
L[i:j] = K |
+L[:i] + K + L[j:] |
+
A la hora de decidir qué versión usar, la versión inmutable es más apropiada para programación funcional y resulta incluos más intuitiva de interpretar. No es extraño ver errores de código donde se espera resultados de las operaciones .sort() o .reverse(), que siempre devuelven None. Para el intérprete de python no hay error, pero a veces nos será difícil darnos cuenta de estos errores:
MODO ERRÓNEO: machacamos la lista con None
+>>> l = [3, 5, 1, 2, 4]
+>>> l_2 = [x*x for x in l.sort()]
+Traceback (most recent call last):
+ File "<stdin>", line 1, in <module>
+TypeError: 'NoneType' object is not iterable
+MODO CORRECTO
+>>> l = [3, 5, 1, 2, 4]
+>>> l_2 = [x*x for x in sorted(l)]
+>>> l_2
+[1, 4, 9, 16, 25]
+
+
+
+ +
-
+
-
+
De hecho, la operación
+L*1es más eficiente queL[:]. ↩
+
+
+ Q2 2019 Survey Results and Call for Proposals
+News on Clojurists Together 07 04 2019
+
+
+ Eliminar elementos de un array en Javascript
+Óscar Lijó 04 04 2019
+Eliminar elementos de un array en Javascript es una tarea habitual para los que desarrollamos en este lenguaje. De hecho, para hacerlo existen una gran cantidad de maneras distintas, según cual sea la necesidad. Seguramente algunas te sonarán y otras no tanto. Pero al final de este post tendrás un cuadro completo de los métodos…
+La entrada Eliminar elementos de un array en Javascript aparece primero en Óscar Lijó.
+ +
+ 
+
+
+ 11 ejemplos de sitios web con degradados
+Blog de Diseño Web Vida MRR 03 04 2019
+Gradient Banner
The HR Manifesto
Grabient Landing Page
D25/Video Production
Centexus Landing Page
Ninety Nine Seconds Game Prototype
DIY Course Landing Page
Natoni Landing Page
Bitframemedia Logo
TinyMind Landing Page
Mindfulness App Onboarding Screens
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+ 
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+ Cómo vender proyctos como freelancer
+Blog de Diseño Web Vida MRR 02 04 2019
+
Para aquellos que empiezan su carrera de freelancer y no saben cómo iniciar su proceso de venta de proyectos, este es el video perfecto para ustedes. No es que sea un arte, pero sí se necesita cierta habilidad para poder vender nuestros proyectos, empezando con buscar a clientes potenciales.
Una vez que sepas a qué tipo de clientes les vas a vender, necesitas saber tu modelo de negocios. En este video les comparto uno de ellos, que es de los más populares actualmente, que es el modelo de servicios. Si te quieres iniciar a vender proyectos la mejor forma es con un esquema de servicios, en donde distribuyes tus costos a lo largo de suscripciones con tus clientes, de tal forma que en vez de que te paguen una sola vez, te paguen constantemente para que tu les sigas ayudando de forma indefinida, o al menos hasta que ya no necesite tus servicios.
El modelo de suscripciones es usado por muchísimos servicios como Netflix o Spotify, y te permite a ti como desarrollador tener presencia con tus clientes de forma constante, a través de seguimiento de proyectos, de soporte o de otros beneficios que harán que te paguen también una cantidad pequeña mensualmente, y que al final para ti es un ingreso que solamente se distribuye a lo largo del tiempo.
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+ 
+
+
+ End of the line
+MonkeyUser 02 04 2019
+
+ 
+
+
+ 3 habilidades importantes que necesitas como desarrollador
+Blog de Diseño Web Vida MRR 01 04 2019
+
La escuela nos enseña ciertas habilidades y tecnologías que nos deben servir en nuestra vida, sin embargo, queda en nosotros seguir el aprendizaje necesario para seguir conociendo lo más nuevo en nuestro entorno. Para un estudiante de ingeniería que desea tener un trabajo como desarrollador o ingeniero en sistemas la cosa no es diferente. Hay habilidades y tecnologías que no aprenderá en la escuela, y es importante desarrollarlas y aprenderlas, porque van a servir de una forma u otra.
Vamos a aprender cuáles son esas habilidades que no nos enseñan en la escuela, pero de todas formas necesitamos aprender.
Git
Git es una de las tecnologías que deberías conocer sin importar si te la enseñan o no en la escuela. Desarrollar la habilidad de versionar tu código, hacer modificaciones y darle un mantenimiento adecuado por medio de branches es una habilidad que, aunque pareciera sorprendente, no todos los desarrolladores saber hacer. Conocer Git te va a dar no una ventaja, sino te va a dar lo indispensable que se necesita en cualquier rol de desarrollo y que no te dicen que lo necesitas hasta que lo tienes que ocupar.
Comunicación
Aprender a comunicarse es una habilidad que no nos enseñan en ningún lado. Cada persona, organización y yo diría que hasta región donde estemos tiene su propia forma de comunicarse, pero es indispensable saber hacerlo para poder obtener resultados. Un problema común de comunicación es saber pedir las cosas, quizá que algún colaborador nos ayude con nuestro código. Algo tan simple como eso puede ser interpretado como que no tienes los conocimientos, o tienes flojera, o quieres que alguien más haga tu trabajo.
Un ejemplo de comunicación efectiva para pedir apoyo en el ejemplo anterior es que se maneje un mensaje de contexto. Si en vez de ir directo a pedir apoyo, se explica todo lo que ya hiciste para llegar al punto donde no puedes avanzar, quizá la otra persona en vez de negarte el apoyo pueda entender que no estás pidiendo ayuda por flojo, sino porque ya recorriste una serie de pasos y nada funcionó. Esto le da un incentivo de poder serte útil y a la vez no crea que está haciendo tu trabajo.
Escribir
Para muchos escribir es plasmar sus pensamientos en un correo o una carta, y la realidad es que no. Escribir correctamente tiene que ver con saber transmitir un mensaje a un grupo de personas, y que esas personas tengan el mismo significado al leer tu mensaje. No todos podemos tener las estructuras gramaticales para elaborar textos complejos, pero sí deberíamos tener la capacidad de redactar un mensaje de tal forma que la intención que tenga se pueda transmitir, y nosotros obtengamos una respuesta.
A nivel de código es importante saber documentar nuestros proyectos, saber documentar errores y poder pedir apoyo usando la técnica de comunicación que mencioné en el punto anterior. Dar mensajes claros en pocas palabras siempre va a ser el objetivo al momento de escribir, ya que la gente no perderá tiempo leyendo un texto sin saber qué es lo que estás queriendo decir o pedir.
+ 
+
+
+ Codecademy vs. The BBC Micro
+Two-Bit History 31 03 2019
+
+
+ Como hacer una redirección en Javascript
+Óscar Lijó 27 03 2019
+Para hacer una redirección en Javascript tenemos diferentes métodos. Y prácticamente todos hacen lo mismo, pero hay matices. Veamos las dos maneras clásicas de hacerlo. La primera es usando window.location.replace(...) y es la manera más correcta de hacerlo. La razón es sencilla estamos hablando de hacer una redirección en Javascript, no de hacer una navegación.…
+La entrada Como hacer una redirección en Javascript aparece primero en Óscar Lijó.
+ +
+ 
+
+
+ Possible Code Contents
+MonkeyUser 26 03 2019
+
+ 
+
+
+ El Atareao: Un bot en Python para Telegram (y en una sola línea)
+Python Hispano 22 03 2019
+Hace unos pocos días Angel, en uGeek, publicó un interesante artículo sobre como crear un bot de telegram con Bash. Igualmente, por mi parte, la semana anterior había publicado un artículo sobre como podías crear tu propio bot con PHP. En este contexto y en el grupo de telegram de uGeek, comenté que se podía hacer de forma similar, un bot en Python para Telegram. Fue justo en ese momento, donde Pedro, MosqueteroWeb, nos propuso un duelo.
+ + + +Y es que no lo puedo evitar. Ya lo comenté en el capítulo número 1 del podcast titulado el peligro de las apuestas. Y es que no puedo resistirme a un reto. Y esta es la razón de este nuevo artículo, que irá encasillado en el tutorial sobre bots para Telegram.
+ + + +En este nuevo capítulo del tutorial, te explicaré como puedes utilizar Python para enviar mensajes, imágenes y audios, de forma relativamente sencilla a un canal o grupo de Telegram. Eso si, el objetivo de este capítulo es hacerlo sin ninguna librería extra.
+ + + +
Un bot en Python para Telegram
+ + + +Tal y como te he comentado en la introducción, el objetivo de este nuevo capítulo del tutorial es implementar un bot en Python, sin necesidad de utilizar ninguna librería externa. Me refiero claramente a una librería cuyo objetivo sea facilitar el acceso a la API de bots de Telegram. Comento este punto, porque si que utilizaré una librería para realizar las llamadas GET y POST, me refiero a Requests.
+ + + +Por otro lado, lo que verás en este capítulo no es un bot en si. Se trata de llamadas a la API. Implementar un bot, considero que es algo mas complejo que una simple llamada. Un bot, debería permitir interactuar con el usuario. Es decir, el bot debe ser capaz de responder ante las acciones del usuario. Incluso, implementar botones, para facilitar esa interrelación entre bot y usuario.
+ + + +Ahora bien, esto último, esta interrelación no es mas que seguir el capítulo 10 de este tutorial en el que te explico lo relacionado con bots, Flask y Nginx.
+ + + +Requests
+ + + +Requests es una librería para HTTP, liberada bajo licencia Apache2, que tal y como la definen sus propios desarrolladores, escrita en Python para seres humanos. La ventaja de utilizar esta librería es que evita las complicaciones de trabajar con HTTP, haciendo que una llamada sea muy, pero que muy, sencilla.
+ + + +Esta librería está disponible tanto para las versiones 2 y 3 de Python. Sin embargo, lo recomendable es utilizar Python 3, y en este sentido, utilizaré esta versión.
+ + + +Instalar Requests para Python 3 en Ubuntu, y en derivadas de Debian, es tan sencillo como ejecutar,
sudo apt install python3-requestsAunque dependiendo de lo que quieras hacer, es posible que lo recomendable sea crearte un entorno virtual en Python, lo que te permitirá olvidarte del sistema en el que estés trabajando.
+ + + +Pasos previos
+ + + +Con independencia del lenguaje de programación o si utilizas librería o no, es necesario crear el bot. Con este objetivo, Telegram dispone de un bot para crer bots. Se trata de BotFather. Te recomiendo que leas el primer capítulo del tutorial sobre crear tu propio bot para Telegram.
+ + + +Enviar mensajes a Telegram con tu bot en Python
+ + + +Una vez te he comentado los puntos de partida, y ya has creado tu bot con BotFather, ya puedes enviar tu mensaje. En python es tan sencillo como crear un archivo de texto, que puede ser mensaje.py, con el siguiente contenido,
#!/usr/bin/env python3
+import requests
+
+requests.post('https://api.telegram.org/bot<TOKEN>/sendMessage',
+ data={'chat_id': '<CHAT_ID>', 'text': '<TEXTO>'})Donde,
+ + + +<TOKEN>token que te ha propocionado BotFather.<CHAT_ID>identificador del canal o grupo donde envías el mensaje.<TEXTO>texto del mensaje que quieres enviar.
Como ves, el compromiso lo he cumplido, en una línea he conseguido enviar un mensaje sin necesidad de librerías externas, a excepción de Requests. Si, es realmente sencillo.
Si quieres ver la respuesta de Telegram, hay que modificar ligeramente el script, tal y como te indico a continuación,
#!/usr/bin/env python3
+import requests
+
+r = requests.post('https://api.telegram.org/bot<TOKEN>/sendMessage',
+ data={'chat_id': '<CHAT_ID>', 'text': '<TEXTO>'})
+print(r.text)Dado que lo que nos devuelve es un json, si quieres aprovechar las facilidades que te da Python, puedes utilizar directamente el módulo json para conocer si la respuesta es correcta. Así, de nuevo, modificamos el script, añadiendo estas matizaciones,
#!/usr/bin/env python3
+import requests
+import json
+
+r = requests.post('https://api.telegram.org/bot<TOKEN>/sendMessage',
+ data={'chat_id': '<CHAT_ID>', 'text': '<TEXTO>'})
+data = json.loads(r.text)
+print(data['ok'])Parámetros opcionales
+ + + +Además del parámetro text también se pueden enviar algunos parámetros opcionales que te van a permitir adaptar el mensaje a tus necesidades. Estos parámetros, comunes a otros métodos, son los siguientes,
parse_modese refiere al formato del mensaje. Aquí tienes dos opciones oMarkdownoHTML. Mi consejo es que utilicesHTMLporque en mi caso he tenido algunos problemas con el guión bajo del markdown.disable_web_page_preview. Cuando se ponen enlaces en los mensajes, Telegram por defecto te muestra una previsualización de la página correspondiente. Con esta opción puedes habilitar o deshabilitar esa previsualización.disable_notification. Cada vez que recibes un mensaje en un grupo un canal, como bien sabes, recibes una notificación, salvo que lo hayas limitado temporal o definitivamente. Sin embargo, tu puedes con este parámetro que no se envie notificación.reply_to_message_id. Esto parámetro lo puedes utilizar para el caso de que estés respondiendo a otro mensaje. Por ejemplo, te puede ser de utilidad para una cadena de mensajes.reply_markup. En esta opción puedes introducir parámetros adicionales, como puede ser un teclado en línea. Esto lo veremos en un capítulo posterior.
Pasando argumentos
+ + + +Esta solución para enviar siempre el mismo mensaje no está mal. Sin embargo, si lo que queremos es enviar diferentes mensajes a diferentes canales, lo suyo es que pasemos, tanto el identificador del canal o grupo, como el mensaje al script. Igualmente esto es muy sencillo. Tan solo tenemos que introducir algunas ligeras modificaciones en nuestro script.
+ + + +#!/usr/bin/env python3
+import requests
+import sys
+
+if __name__ == '__main__':
+ if len(sys.argv) > 2:
+ requests.post('https://api.telegram.org/bot<TOKEN>/sendMessage',
+ data={'chat_id': sys.argv[1], 'text': sys.argv[2]})Como primer parámetro pasaremos el identificador del chat, mientras que como segundo parámetro el texto. En este caso el texto debe ir entre comillas.
+ + + +Enviar imágenes a Telegram con tu bot en Python
+ + + +Una vez que ya has visto lo sencillo que es enviar un mensaje de texto utilizando Python, vamos a algo ligeramente mas complicado. Vamos a enviar una imagen. En este caso tenemos dos opciones, o bien, enviamos la url de la imagen, en el caso de que ya esté en subida a algún servidor, o como segunda opción la subimos. Esto, con requests es realmente sencillo.
- Primer caso. Utilizamos una imagen disponible en algún alojamiento web,
requests.post('https://api.telegram.org/bot<TOKEN>/sendPhoto',
+ data={'chat_id': <CHAT_ID>, 'photo': <PHOTO_URL>, 'caption': <TEXT>})En este caso debes indicar la ruta donde está alojada la imagen, así como el título o un texto que acompañe la imagen. Esto último es opcional, si no le quieres añadir un texto, simplemente, no pongas ese último parámetro.
+ + + +- Segundo caso. Subimos nuestra propia imagen,
requests.post('https://api.telegram.org/bot<TOKEN>/sendPhoto',
+ files={'photo': (<ARCHIVO>, open(<ARCHIVO>, 'rb'))},
+ data={'chat_id': <CHAT_ID>, 'caption': <TEXT>})Aquí <ARCHIVO> se corresponde con la ruta donde se encuentra el archivo de la imagen que queremos subir a Telegram.
¿Fácil verdad?
+ + + +Enviar audio y voz a Telegram con tu bot en Python
+ + + +Una vez hemos superado las opciones para enviar mensajes e imágenes, vamos al siguiente paso, de este artículo, que es enviar audio.
+ + + +En este caso, también tienes dos opciones para enviar audio. La primera de las opciones es enviarla como un mensaje de voz, mientras que la segunda es como un archivo de audio. Así, en el primer caso, como mensaje de voz sería tal y como ves a continuación,
+ + + +requests.post('https://api.telegram.org/bot<TOKEN>/sendVoice',
+ files={'voice': (<ARCHIVO>, open(<ARCHIVO>, 'rb')),
+ 'thumb': (<ARCHIVO2>, open(<ARCHIVO2>, 'rb'))},
+ data={'chat_id': <CHAT_ID>, 'caption': <TEXT>})En este caso, también es posible añadir un parámetro extra que es la duración del mensaje de voz en segundos. Para esto utiliza duration.
Mientras que el segundo, como archivo de audio, será de la siguiente forma,
+ + + +requests.post('https://api.telegram.org/bot<TOKEN>/sendAudio',
+ files={'audio': (<ARCHIVO>, open(<ARCHIVO>, 'rb')),
+ 'thumb': (<ARCHIVO2>, open(<ARCHIVO2>, 'rb'))},
+ data={'chat_id': <CHAT_ID>, 'caption': <TEXT>})Además de los parámetros anteriores, es posible enviar un nuevo un nuevo archivo. Este tipo de archivo es lo que se conoce como una miniatura o en inglés thumbnail. Y es la típica imagen que acompaña al mensaje de voz. Aunque lo cierto es que lo he visto en pocas ocasiones.
La parte de la miniatura es completamente opcional, y por tanto la puede omitir. Al igual que en otros casos, también se puede utilizar un enlace a una imagen que ya esté disponible desde un servidor. Así, en ese caso, el método tendría el siguiente aspecto,
+ + + +requests.post('https://api.telegram.org/bot<TOKEN>/sendAudio',
+ files={'voice': (<ARCHIVO>, open(<ARCHIVO>, 'rb'))},
+ data={'chat_id': <CHAT_ID>, 'caption': <TEXT>, 'thumb': <THUMB>})Indicarte que las características de las miniaturas están fijadas. En este sentido el archivo tiene que ser en formato JPEG y tener un peso máximo de 200 kB, y unas dimensiones iguales o inferiores a 90 px.
En ambos casos la parte del título es opcional, con lo que de nuevo, la puedes omitir. Además es posible, añadir algunos parámetros opcionales, como puede ser el formato del texto. En cualquier caso, te recomiendo una visita a la documentación de la API de bots, para tener siempre la última documentación.
+ + + +Enviar una video nota
+ + + +Desde hace recientemente poco, en referencia a la publicación de este capítulo del tutorial, es posible enviar vídeos desde Telegram con una duración inferior a un minuto. El método que tienes que utilizar será el siguiente,
+ + + +requests.post('https://api.telegram.org/bot<TOKEN>/sendVideoNote',
+ files={'video_note': (<ARCHIVO>, open(<ARCHIVO>, 'rb')),
+ 'thumb': (<ARCHIVO2>, open(<ARCHIVO2>, 'rb'))},
+ data={'chat_id': <CHAT_ID>, 'caption': <TEXT>,
+ 'duration': <DURATION>, 'length': <LENGTH>})Los únicos parámetros obligatorios son el archivo de vídeo y el identificador del chat. El resto de parámetros son totalmente opcionales. Como ves, aquí he incluido dos nuevos. Por un lado la duración del vídeo y la dimensión del vídeo. Este caso se corresponde con el diámetro.
+ + + +Enviar cualquier tipo de archivo a Telegram con tu bot en Python
+ + + +Si en lugar de una imagen o un audio quieres enviar cualquier otro tipo de documento, existe un método específico para ello. El uso es el siguiente,
+ + + +requests.post('https://api.telegram.org/bot<TOKEN>/sendDocument',
+ files={'document': (<ARCHIVO>, open(<ARCHIVO>, 'rb')),
+ 'thumb': (<ARCHIVO2>, open(<ARCHIVO2>, 'rb'))},
+ data={'chat_id': <CHAT_ID>, 'caption': <TEXT>})Al igual que en el caso de enviar un archivo de audio, también es posible mostrar una pequeña miniatura que se corresponda con el documento que estamos enviando. De nuevo, esto es completamente opcional.
+ + + +Conclusiones
+ + + +Como puedes ver, en una sóla línea de código, o casi, es posible enviar un mensaje utilizando los bots de Telegram. La cuestión es que poco a poco, esto se va complicando a medida que quieres enviar otro tipo de archivos y documento. Aunque tampoco en exceso, como tu mismo has visto.
+ + + +Dado lo extenso de los métodos del API de bots de Telegram, dejo para un nuevo capítulo otros métodos, que seguro te serán de utilidad. Y para un tercer capítulo dentro de esta mini serie, el uso de teclados en línea.
+La entrada Un bot en Python para Telegram (y en una sola línea) aparece primero en El atareao.
+
+
+ Mezclar colores con CSS
+Óscar Lijó 21 03 2019
+Mezclar colores con CSS es un tema del que no se suele hablar mucho. Y eso que seguro que todos tenemos claros que mezclando colores obtenemos colores nuevos.Ya desde pequeños en el colegio jugábamos a mezclar colores con ceras o lápices. Luego fuimos aprendiendo que si mezclamos todos los colores de la paleta obtenemos negro…
+La entrada Mezclar colores con CSS aparece primero en Óscar Lijó.
+ +
+
+ Hypermedia REST
+Óscar Lijó 20 03 2019
+Hypermedia REST es una manera de enfocar nuestras API REST. Actualmente existe un gran debate acerca cual es la mejor manera de construir una API. Entre las distintas tecnologías que existen podemos destacar SOAP y REST como las más conocidas tradicionalmente. Y posiblemente GraphQL como la especificación moderna mas prometedora. De hecho si quieres saber…
+La entrada Hypermedia REST aparece primero en Óscar Lijó.
+ +
+ 
+
+
+ Sprint
+MonkeyUser 19 03 2019
+
+ 
+
+
+ Stepping down from Fathom
+Danny van Kooten 17 03 2019
+I have an announcement to make. Less than a year ago, Paul Jarvis and I started working on Fathom (simple and transparent website analytics).
+ +We managed to make a lot of progress during our first year and I’m more than a little proud of what Fathom is today. I’m running it on most of my sites and I’d say it’s very much a viable alternative for Google Analytics for a lot of websites already.
+ +
The open-source community around Fathom is very much alive and kicking. The GitHub repository for Fathom currently boosts over 5.000 GitHub stars and Fathom has been a trending Go project for pretty much every week over the last year!
+ +And the Docker image has been pulled over a million times, even though Fathom is already a single (embedded) binary that is super easy to deploy to your infrastructure of choice. There’s even a one-click installer if you’re on DigitalOcean.
+ +The software we built itself proved very effective in terms of performance. A single $5 VPS can easily handle tens of millions of pageviews per month, as proved by some of the bigger customers on Fathom’s PRO plans.
+ +Stepping down
+ +To think that Fathom would be so well received and grow so rapidly during its first year is amazing and I’m super proud to have been a part of that.
+ +Have been, because going forward, I will not be actively involved with Fathom anymore. Fathom itself is not going anywhere though. Paul is now joined by Jack Ellis with whom he will be continuing the project. Having seen them work together during the handover phase, I completely trust in their abilities to keep making Fathom better.
+ +I am a little sad to leave Fathom behind but juggling its responsibilities with being a newbie dad and running Mailchimp for WordPress while also wanting to spend less time behind a computer proved way harder than anticipated.
+ +At the same time, I’m stoked to see their plans unfold over the next few months. I’m confident they will take good care of what we managed to build over the past year.
+ +
+
+ TIL how to interactively fix a failing test
+Lisp journey 12 03 2019
+I knew it was possible, but I got to try it recently.
+ +Here I run a test with fiveam. It fails. I tell fiveam to enter
+the debugger on failures with
(setf 5am:*on-error* :debug)
+so we have an immediate feedback and we can re-run the test from where +it left off by choosing the appropriate restart.
+ + + +Other test frameworks like Parachute allow that.
+ +This is one of the things that make development in Common Lisp +enjoyable and faster than with other workflows. Also, it’s built-in, +there is no fancy editor plugin or configuration.
+ ++ +
In the debugger:
+ +-
+
<enter>on a backtrace shows more of it
+von a backtrace goes to the corresponding line or function.
+- more options with the menu. +
+
+ February 2019 Monthly Update
+News on Clojurists Together 12 03 2019
+
+
+ How to Use Grouping Sets in Django
+Haki Benita 09 03 2019
+How we cut a heavy admin dashboard response time in half with advanced SQL and some Django hackery. I recently had the pleasure of optimizing an old dashboard. The solution we came up with required some advanced SQL that Django does not support out of the box. In this article I present the solution, how we got to it, and a word of caution.
+
+
+ Olimpia Valencia
+Andanzas de una ambientóloga . . . 07 03 2019
+
+ 
+
+
+ Github deja de dar soporte a jQuery
+Blog de Diseño Web Vida MRR 06 03 2019
+
Github deja de dar soporte a jQuery, con lo que pasa a ser otro servicio que empezó a usar jQuery para poder dar servicio a todos sus usuarios y repositorios, pero ahora ya está dejando de lado la librería para poder usar frameworks modernos que no dependan tanto de una sola implementación.
En este video les explico las ventajas de migrar de jQuery, y los retos a los que se está enfrentando el equipo de desarrollo de Github al querer modernizar su sitio.
No olviden suscribirse a mi canal de Youtube para ver todo el contenido adicional que se genera para los desarrolladores y diseñadores web
+ 
+
+ 
+
+
+ 10 sitios web con animaciones impresionantes
+Blog de Diseño Web Vida MRR 05 03 2019
+
Se pueden hacer diferentes tipos de animaciones en un sitio web, desde las básicas con CSS, las complejas usando Javascript, pero los sitios web que les presento llevan a otro nivel este tema. Les presento 10 sitios web con animaciones impresionantes, donde combinan CSS, SVG, WebGL y otras técnicas de animación para crear estos increíbles efectos de navegación en los sitios web
+ 
+
+ 
+
+
+ New Model
+MonkeyUser 05 03 2019
+
+
+ These Years in Common Lisp 2018
+Lisp journey 28 02 2019
+It’s been already a little more than a year that I began my Lisp +journey. I made quaterly news digests, mainly from reddit’s +feed:
+ + + +Time has come for a yearly overview ! What happened in the Common Lisp +world ? Are there (or groundbreaking promising useful fun) projects, +articles, discussions, tutorials ?
+ +No need to say, I won’t reference everything we find in the quaterly +posts, which don’t list all new projects appearing on Quicklisp (we +can find these in the +monthly Quicklisp releases) or Github.
+ +I hope this overview will sharpen your interest on what is in my +opinion an under-sold and still very promising language and plateform, +that I happen to like more and more (and sooo more than Python ;) ).
+ +Happy discoveries.
+ + + +Table of Contents
+ +-
+
- Documentation +
- Implementations +
- Projects + + +
- Articles +
- Other screencasts +
- Discussion + + +
Documentation
+ +Common Lisp’s online documentation could be more thorough and +welcoming. Fortunately, a few of us revived some projects and work on +it -my favourite project being the Common Lisp Coobook. This year, we +got tutorials on:
+ +-
+
- Datastructures +
- Debugging, including how to interactively debug a spacecraft, +
- the Common Lisp Object System (CLOS) +
- Loop, iteration, mapping +
- Database access and persistence +
- Error and condition handling +
- Numbers and multidimensional arrays +
- Scripting and building self-contained executables +
- Working with types +
along with many improvements on other pages, like on getting started and editor support.
+ +Which brings me to it: the editors situation is much more open than +you think:
+ +-
+
- The editor of choice is still Emacs with Slime (or +Sly), +
- However, we can get started with Emacs and Lisp in 3 clicks with Portacle, a self-contained batteries-included sbcl-included portable Emacs tailored for CL, +
- For Vim and NeoVim we have SLIMV, VLIME, and plugins can be written for NeoVim using cl-neovim. +
- Or if we want an editor written in cl, there’s the self-contained Lem editor, which also works for Python, Go, Rust, Nim, Scheme, HTML, JSX, along with a directory mode, an experimental LSP mode, calc-mode, and more, +
- Not to forget that Mac Os X users can use the Clozure Common Lisp IDE +
- All editions of LispWorks (including the free) include the LW IDE +
- For users of Eclipse IDE, there is the Dandelion plugin +
- For popular editors, the experience is getting very good on Atom and the popular Visual Studio Code can be made to work with CL using cl-lsp. +
- We have an ipython-like REPL (cl-repl), +
- and for interactive notebooks, we have Jupyter kernels and yet another +notebook (Darkmatter). +
A very welcome improvement is the Common Lisp fundation’s website: +https://common-lisp.net/ It got a massive update and is now +attractive. We had http://lisp-lang.org/ (don’t miss its success +stories section (did you know that pgloader was re-written from Python to CL ? :) )), but common-lisp.net was a googlers’ honey pot.
+ +This website uses two “awesome” lists that were created or massively +furnished last year:
+ +-
+
- the Awesome-CL list, +updated with hundreds of commits, which hopefully makes for a more +discoverable and appealing ecosystem, and +
- Awesome Lisp Companies: +it was needed because Lispers didn’t know a lot of companies using +CL appart from IRobot, Google’s ITA (powering +Kayak, Orbitz and +others), Grammatech, YCombinator, Siscog or other dead ones. +
Other places to learn Common Lisp include:
+ +-
+
- cl-exercise: a Common Lisp Learning System running on browsers +
- coding schools, like Kattis +
- and competitive Programming websites like CodeForces, +HackerEarth, HackerRank, and CodeChef. +
- lastly, Peter Norvig’s book Paradigms of Artificial Intelligence Programming is available on Github +
We also regularly have new screencasts to enjoy:
+ +-
+
- a lot being from Baggers: he does the following and he streams live nearly weekly
+
+
-
+
- little bits of Lisp: short videos to learn Lisp basics +
- lots of bits of Lisp: long videos to dive deep in advanced subjects (macros, CFFI,…) +
- Pushing pixels with Lisp: mostly working with OpenGL +
- and more ! +
+ - Shinmera +has lots of videos too, we can see him working on game engines, +games, his libraries, Qt applications and more, +
- the CL study group (here, an introduction to Screamer, a non-deterministic programming library) +
Implementations
+ +Time is good for Common Lisp implementations. Most date back from
+decades and already proved what they can do (remember, SBCL is a
+descendant of the Lisp that went to space). Hence the lack of hype,
+IMO. Yet, many are in active development, and keep improving. As
+/u/defunkydrummer observed:
++ +We are lucky to live in a time where Lisp development is still ongoing, many teams carrying the flag of open-source Lisp:
+ ++
+- SBCL (new release today)
+- SICL (last commit 2 hours ago)
+- ECL (last commit, yesterday),
+- CLASP (last commit 2 days ago)
+- CCL (last commit 7 days ago),
+- CLISP (two weeks ago),
+- CMUCL (1 month ago)
+- ABCL (3 months ago)
+
SBCL has monthly releases. If you read the release notes, you might worry:
+ +++ +the amount of changes in each release is decreasing these years
+
but, as /u/baggers notes:
++ +I think the commits tell a slightly different tale though. There is always a lot of background ‘making stuff better’ work than won’t appear as the explanation would either be ultra internal and specific or would be super vague and very similar each month (for example ‘stuff is slightly faster’).
+ +For one that would be overly specific this one might make for a good example. It’s grand work, but doesn’t surface in any specific lisp feature, stuff is just better.
+
Furthermore, a maintainer:
+ +++ +Or the developers are too lazy to describe their changes.
+
which isn’t a good reason ;)
+ +We got a new release of Corman Lisp, a high performance Windows/32bit specific implementation with a built in IDE,
+ +we have CLASP, targetting C++ through LLVM (see “Lessons Learned Implementing Common Lisp with LLVM”), built with the Cleavir compiler, part of SICL, a very +new implementation of Common Lisp with fresh ideas,
+ +we have ABCL targetting the JVM, Embedable Common Lisp, without +forgetting active commercial ones, like LispWorks and AllegroCL. While +I’m at it, you might want to have a look at +MOCL for IOs, Android and OSx.
+ +We got a nice talk by Clozure Common Lisp’s maintainer: +this Old Lisp (this one may be the second +most used implementation, particularly good for development – super fast +compilation times (I heard it compiles itself in seconds), advising, watched objects, its own IDE).
+ +Last note, a SBCL maintainer started a RISC-V port: First RISCy Steps – Porting SBCL to the RISC-V
+ +So: welcome to this new world. It’s bigger than I thought, for sure.
+ +Projects
+ +I only list some projects that can be of interest to anybody. For the full stuff see the quaterly posts !
+ + + +New projects
+ +-
+
- Next browser 1.2.0 is out!: a browser exposing all its internals to CL. Be productive. +
- CANDO - A Computational Chemistry programming environment integrating Common Lisp and C++ based on the Jupyter notebook +
- Coalton, a dialect of ML embedded in Common Lisp (alpha) +
- Voxel game engine (Minecraft) - a Minecraft engine. Allows for interactive changes. +
- Emotiq - blockchain in Common Lisp +
- Temperance - logic programming (in development, reached v1.0.0) +
- MAGICL: Matrix Algebra proGrams In Common Lisp - Rigetti Computing (quantum computing) +
- SHCL: An Unholy Union of POSIX Shell and Common Lisp (reddit) +
- JSCL 0.7.0 now supports CLOS thanks to the work of vlad-km +
- cl-torrents 0.9 - readline interface and 1337x.to scraper - a simple tool to search for torrents on popular trackers. My first CL app. Web and GUI interfaces in the making. +
- Introducing Seed: An Interactive Software Environment in Common Lisp +
- Tovero is a 3D modeling system for Common Lisp +
- RMSBolt: See what your compiler is going inside of Emacs (has minimal support for Common Lisp) +
- pngload: A PNG (Portable Network Graphics) image format decoder +
- cl-vep: a video effects processor +
- algebraic-data-library +
- Petalisp: Elegant High Performance Computing +
- wiki-lang-detect: Text language identification using Wikipedia data +
- Dufy, a color library +
- ppath, a path manipulation library +
- cl-statistics.lisp +
- Powerlisp: A simple tool to automate your work with dmenu/rofi +
- json-mop: A metaclass for bridging CLOS and JSON objects +
- clsh: a set of Lispy bindings for running and composing *nix processes +
- filtered-functions - enables the use of arbitrary predicates for selecting and applying methods. +
Web
+ +-
+
- Weblocks’ new quickstart - +Weblocks is an isomorphic web frameworks that allows to write +interactive web apps without writing Javascript (nor writing code that +transpiles to JS). It is seeing a massive update right now. Being Lisp, +we can build a self-contained executable of our web app, send it to +the server, run it and see it from the outside. +
- three email libraries +
- reddit1.0 source code (comments), then Reddit’s code runs on SBCL. See also reddit. +
- Interactive Common Lisp code snippets in any web page +
- arboreta-wasm - Common Lisp tooling for WebAssembly +
For web libraries, see https://github.com/CodyReichert/awesome-cl#network-and-internet
+ +GUI
+ +-
+
- nodgui - yet another Tcl/Tk-based GUI package for Common Lisp (based on Ltk, with syntax sugar and more meta-widgets) +
- IUP bindings GUI stuff (in the works) +
- YstokWidgets Professional Edition +
- MIDGETS - A collection of CAPI widgets and utilities +
- subtext: A mostly-text-based UI bridges Common Lisp objects and runs of text. Minimal text-based user interface +
- ftw: Common Lisp Win32 GUI library +
- Cocoa interface code written in Lisp for use with Clozure Common Lisp +
- McCLIM 0.9.7 “Imbolc” release +
- Demo SBCL script using Gtk +
- Demo ABCL script using Java Swing +
for GUI libraries: https://github.com/CodyReichert/awesome-cl#gui
+ +Package management
+ +Quicklisp is the de facto package manager, but new projects come to +complement it and bypass its limitations:
+ +-
+
- the second version of Ultralisp is available - Ultralisp is an important project that fills a gap. It is a quicklisp distribution which updates every 5 minutes. It is also a Weblocks application! +
- quicksys - installs systems from multiple Quicklisp distributions. +
For more options, see Qlot (install and pin libraries locally, like +Python’s virtualenv) and Roswell.
+ +Deployment
+ +-
+
- Apache Thrift gains CL support +
- s2i-lisp: Common Lisp + Quicklisp OpenShift Build Image +
- lisp-images: Docker images for common lisp development (with some others, see the awesome-list) +
- A docker container for CL development (also lisp-devel, CI on CL Cookbook) +
- Kubernetes Client Library for Common Lisp +
- Heroku buildpack for Common Lisp +
- cl-aws-custom-runtime - An example of using Common Lisp (SBCL) as a custom runtime on AWS lambda. +
- prometheus.cl - Prometheus.io client. Grafana dashboard for SBCL and Hunchentoot metrics (memory, threads, requests per second,…). +
We can also deploy apps on Digital Ocean, and no need to say that +deploying a +self-contained executable +is easy, +connecting to a remote instance +too.
+ +Music
+ +-
+
- Music: Music framework for musical expression in Common Lisp with a focus on music theory (built from scratch, on development) +
- Composing in Lisp with Csound +
- Shuffletron, a Common Lisp Music Player for the terminal +
see also audio and music composition software
+ +(re)Discoveries
+ +-
+
- lfarm - a library for distributing work across machines (on top of lparallel and usocket) +
- Screamer - nondeterministic programming. Augment Common Lisp with practically all of the functionality of both Prolog and constraint logic programming languages (10 yo, Nikodemus) +
- quid-pro-quo: a contract programming library in the style of Eiffel’s Design by Contract +
- Cells, spreadsheet-like expressiveness for CLOS +
- cl-bibtex: A compatible re-implementation of the BibTeX program in Common Lisp, with a BST-to-CL compiler +
- C language syntax embedded in Common Lisp +
- gendl - Generative Programming and Knowledge-based Engineering (KBE) system embedded in Common Lisp +
- Cognitive Robot Abstract Machine = Common Lisp + ROS +
- Esrap - a packrat parser for Common Lisp +
- C-Mera, a Common Lisp source-to-source compiler to generate C/C++ +
- cl-bench - Common Lisp benchmarking suite +
- QGAME: Quantum and Gate Measurement Emulator +
Articles
+ +-
+
- A Road to Common Lisp (hacker news comments). You should read this one. +
- How the strengths of Lisp-family languages facilitate building complex and flexible bioinformatics applications +
- Writing a natural language date and time parser - internals of the Common Lisp library Chronicity +
- Implementing Hunchentoot custom sessions +
- Overview of Documentation Generators (codex, coo, declt, staple, cldomain) + +
- Converter of maps from Reflex Arena to QuakeWorld. cl-yacc, 3d-matrices +
- Debugging Common Lisp in Slime +
- Packages in Common Lisp, a tutorial (pdf) +
- How to write test fixtures for FiveAM - Dark Chestnut +
- Franz and Semantic Web Co. Partner to Create a Noam Chomsky Knowledge Graph +
- Compiler basics: lisp to assembly +
- Marvin Minsky - Scientist - The beauty of the Lisp language +
- Excavating a Common Treasure: Common Lisp +
- Fun with Macros: If-Let and When-Let / Steve Losh +
- Extempore - The design, implementation and application of a cyber-physical programming language, Andrew Sorensen, Thesis, 2018 (PDF) +
- Uniform Structured Syntax, Metaprogramming and Run-time Compilation +
- Simple expression evaluator comparison between Haskell, Rust, and Common Lisp +
- Lisping at JPL +
and also
+ +-
+
- Lisp, Jazz, Aikido: Three Expressions of a Single Essence +
- Why lisp - biolisp +
- Fun with Macros: Gathering / Steve Losh +
- Experience writing a full featured livejournal blog client in Common Lisp. Part 2: client logic +
- The (Un)common Lisp approach to Operations Research (2012) +
- Alien: Return of Alien Technology to Classical Planning +
- Emacs + ECL on Android +
- Generic, consistent and dotted access of data structures with Access - lisp-journey (reddit) +
- LLVM’s garbage collection facilities and SBCL’s generational GC +
- A bunch of utilities from (again) sjl: higher order functions, sequences, debugging, profiling. +
- The return of cl-notebook +
- Testing the SERIES package +
On games:
+ +-
+
- About Making Games in Lisp - Gamedev +
- Creating a (Non-Trivial) Lisp Game in 2018 (they just launched a Crowdfunding) +
- A Story of (defun games ()) +
- Getting Started With trivial-gamekit +
Other screencasts
+ +-
+
- Lisp, The Quantum Programmer’s Choice - Computerphile episode 2 +
- McCLIM + Maxima: plot manipulation +
- McCLIM + Maxima: vector demo +
- Comfy Lisp Programming - Project “Wikify” | Episode 2 @ 10am PST +
- Common lisp and C++17 Live coding stream | TinyCDN CFFI Interop | Episode 13 +
- Growing a Lisp compiler - Amsterdam Lisp +
- Web Development in Emacs, Common Lisp and Clojurescript - Potato (Slack-like) +
Discussion
+ +-
+
- Lisp and the remote agent - aka Lisp in a spacecraft - with an AMA of Ron Garret +
- How to make (Common) Lisp popular? +
- Feedback from a new LispWorks user (how is LispWorks the company going ?) +
- How do you normally use a program once written ? +
- Structs vs Parametric Polymorphism (an answer to the “switching from Common Lisp to Julia - thoughts ?” post) also this discussion +
- How to work on a project and make sure dependencies are tracked correctly? +
- Does anyone else hate LOOP? +
- What does it take to understand the true power of Lisp? +
- How did Lisp make your life easier ? +
- Should local variables be avoided when possible when doing functional programming? +
- Is ABCL an active project and does it support JRE 1.11? +
- Has the Gnu Coreutils ever been implemented in Lisp? If not, would that be a worthwhile project? +
- Common Lisp and Machine Learning these days +
- Has anyone considered or started a project to write a CL implementation in WebAssembly? +
- What do you recommend to work with SQL databases ? What’s your experience with Mito ? and sqlite only interface: cl-sqlite or cl-dbi ? +and is there an ORM that generates classes from table definitions ? +
Learning Lisp
+ +-
+
- I want to try Lisp, how should I begin? +
- What lisp dialect for “real world” applications? +
- What do commercial Lisps offer that frees don’t? +
- Which (non-Clojure) Lisp to learn first? +
- Can CL implement Clojure’s keyword as function syntax? +
- Why did you decide to learn Lisp? +
- How do you go about starting a Common Lisp Project? A beginner looking for pointers. +
- As a newbie, what I will miss if I choose Racket over Common Lisp? Or if I happen to learn both at somepoint in future, choosing Racket/Common Lisp now would make sense? +
- What can other languages do that Lisp can’t ? +
Common Lisp VS …
+ + + +-
+
- How did the Common Lisp community survived without the equivalent of clojure.spec ? +
- Is there a Lisp that is considered “excellent” about error handling ? +
- Lisp Dialect survey +
- the Julia challenge +
- Python pitfalls ? +
- How a Common Lisp programmer views users of other languages (humor) +
- Miller School Researchers Help Push the Limits of Programming Languages in Biology +
- Lisp vs Java (thought you guys might find this humorous) +
- What other languages besides Lisp do you enjoy programming in? +
+ +
Enjoy the material, and see you soon !
+ ++ +
thanks to /u/defunkydrummer for proofreading.
fix or improve this article on Gitlab.
+ +
+ 
+
+
+ YAGNI
+MonkeyUser 26 02 2019
+
Community request (with bugs)
+
+
+
+
+ Updating our tracking prevalence metrics
+WhoTracksMe blog 21 02 2019
+
+ 
+
+
+ 9 to 5
+MonkeyUser 19 02 2019
+
+
+
+
+ Adblockers Performance Study
+WhoTracksMe blog 14 02 2019
+
+ 
+
+
+ Quick Fix
+MonkeyUser 12 02 2019
+
+
+ January 2019 Monthly Update
+News on Clojurists Together 11 02 2019
+
+
+ Schibsted, patrocinador Platinum. Saca lo mejor de ti con el reto de Schibsted Spain
+FrontFest 08 02 2019
+
+
+ Conoce Ryanair Labs, patrocinador Gold del FrontFest 2019
+FrontFest 06 02 2019
+
+
+ Paradigma, patrocinador Platinum. SOMOS DISTINTOS, SOMOS PARADIGMA
+FrontFest 05 02 2019
+
+ 
+
+
+ Pivoting
+MonkeyUser 05 02 2019
+
+
+ State of Clojure 2019 Results
+Clojure News 04 02 2019
+
+
+
+
+
+
+Welcome to the annual State of Clojure survey results! Every year we survey Clojure and ClojureScript developers to evaluate the state of the language and its users. Thank you to everyone that took the time to complete the survey and provide your input. This year, we had 2461 respondents. Some highlights:
+
+
+-
+
-
+
Clojure is used by many companies for web development, commercial services, and enterprise apps in a broad set of domains including financial services, enterprise software, retail, advertising, health care, and more.
+
+ -
+
Clojure is valued for its idiomatic support for functional programming, immutable data, interactive REPL, and ease of development.
+
+ -
+
Clojure and its community are active and vibrant, as seen in the many thriving discussion forums, conferences, and user groups, with active involvement in community library development.
+
+
+
+For more details and the full results, see below.
+
+
+A Language for Work
+
+
+
+
+In the first Clojure survey in 2010, 27% of respondents reported using Clojure for work and 33% for serious hobby projects. This number has steadily grown over the years and we now see 66% using it at work and 54% using it for serious hobby projects.
+
+
+Clojure is being used in a wide variety of domains - web development (81%) and open source (48%) of course, but also building and delivering commercial services (31%) and enterprise apps (22%). This work occurs in a wide variety of industries - financial services, enterprise software, consumer software, retail, media/advertising, healthcare, education, and many more.
+
+
+For the last four years, the percentage of Clojure developers in 1-10 person companies has fallen, this year to 35% (compared to 44% 3 years ago). We saw increases in developers working at companies sized 1000+ and 11-100. We also saw the number of consumers of these Clojure projects as less "in team" and more "outside team" or "outside the organization".
+
+
+We added a new question this year to gauge the general experience level of Clojure developers. Almost half of Clojure users (49%) had 11 or more years of experience with 21% having 21 years or more. A recent JVM ecosystem survey asked a similar question and for comparison saw 42% had 11 or more years of experience and only 3% had 21 or more years. Clojure developers tend to be more experienced on average than other JVM developers.
+
+
+Survey comments said:
+
+
+-
+
-
+
"Thanks to Clojure and ClojureScript I can make a living building and maintaining large systems and delivering complex solutions on time. Thank you!"
+
+ -
+
"Clojure is thoughtfully designed and stable. It’s a dynamic, functional lisp that can actually be sold to the bosses. (A sentence I never thought I would write)."
+
+ -
+
"There is no way my team could pull all the rabbits out of hats that we do working in any other language. The only thing I ever seriously worry about, about Clojure, is how to ensure I get to work in Clojure and with Clojurists again should my current gig come to an end."
+
+
+
+Hundreds of companies and tens of thousands of Clojure developers are working in Clojure or ClojureScript every day, using it as the foundation of their business. The survey indicates that Clojure developers are increasingly using it more for work, at bigger companies, impacting ever larger groups of users.
+
+
+Strengths of Clojure
+
+
+
+
+For years we have asked people what aspects of Clojure were most important to them. These answers are remarkably consistent and this year was no different. However it is good to reexamine these strengths to see why developers value Clojure. The big four that are always at the top of the list are: functional programming, immutability, the REPL, and ease of development. These traits are interrelated. Language support for immutable persistent data structures makes functional programming idiomatic and effective. A REPL on a live, growing system, with data loaded, is a great way for developers to try their new code in context as it is written, improving quality.
+
+
+Other important features include host compatibility / interop (allowing us to take full advantage of the underlying platform and its libraries, whether that’s the JVM or JavaScript), the community, runtime performance, expressive syntax, concurrency support, and a shared language across tiers.
+
+
+Some comments about the language:
+
+
+-
+
-
+
"Quality permeates Clojure. Language design, library design, interactive development, community architecture experience, all top notch."
+
+ -
+
"Clojure/script is allowing me to create things that would be impossible in other languages."
+
+ -
+
"Clojure is beautiful, functional and concise. It really rejuvenated my love for programming."
+
+ -
+
"I really appreciate the well thought out design of Clojure. We feel that Clojure gives us distinct advantages while providing a language with minimum disruption."
+
+
+
+
+
+ Vibrant Community
+
+
+
+
+The Clojure community is active, growing, and always helpful. Over the years, the primary communication mechanisms have changed along with the industry varying from IRC to the mailing lists to in recent years, Slack. We’ve been tracking this for a couple years now. Slack continues to be strong with 64% of respondents using it (note that this may be biased by where we advertised the survey!). The Clojure subreddit continued its strong rise to 55% use. ClojureTV on YouTube was a new answer this year but almost half are using it to watch Clojure videos. The official Clojure mailing lists had another drop this year as people shift away from "old school" mailing lists. And the original place where communication happened for Clojure is IRC which continued to fall out of use, now at only 7%.
+
+
+We also added a new question to gauge how users of Clojure interact with the ecosystem. 96% reported being happy users of the language and libraries, 65% were building services or products, 51% were advocating for Clojure in their organization. More than a quarter (28%) were active in helping new users (something very common to see on Slack, Reddit, or the mailing lists). And 25% reported creating or maintaining open source libraries, filing issues on libraries (17%), or providing pull requests for fixes (15%).
+
+
+Some quotes from users:
+
+
+-
+
-
+
"It’s been great watching the ecosystem converge on excellence these past years, thanks so much for all the work and careful design!"
+
+ -
+
"I love how the community continues to improve, and people generally are friendly."
+
+ -
+
"Thanks for a great language, a steady hand at the wheel, and a passionate community!"
+
+
+
+ En BABEL buscamos gente como tu, ¿nos conocemos?
+FrontFest 04 02 2019
+
+ 
+
+
+ Moving from Go to PHP again
+Danny van Kooten 03 02 2019
+Remember when I ditched Laravel for Golang?
+ +Well, after 2 years on Go, our shop applications are powered by PHP again.
+ +Why?! You already said it was probably a bad business decision, and then you spend even more time on it?! Well, yeah, several reasons actually.
+ +PHP improved a lot
+ +PHP improved a lot during the last 3 years. It added scalar argument type declarations, return type declarations, multi-catch exceptions, impressive performance improvements and many more general improvements.
+ +Symfony4 is a game changer
+ +I’ve always been a big fan of Symfony’s compatibility promise and their impressive 13-year track record proves they mean it.
+ +So when Symfony4 was released and I heard good things about it, I took it for a test drive by implementing a tiny part of our application in it.
+ +Conclusion: it’s great. Really, really great.
+ +A lot of effort went into simplifying the setup, making it a lot faster to bootstrap a Symfony application with much less work required configuring bundles. It’s now rivaling Laravel’s rapid development while at the same time encouraging decent development practices to ensure you don’t shoot yourself in the foot. And it performs really well.
+ +It was relatively easy to port our old Laravel application to Symfony, implement some new features the Go version of our application offered and undo some of the shortcuts I took earlier (most of them because of Laravel’s global helpers).
+ +A nice side effect is that I’ve managed to substantially increase our test coverage in the process. Writing the same application in terms of functionality for a second third time really helps in that regard.
Symfony’s debug bar is an amazing tool. It shows you what happened during the journey from request to response, notifies you of warnings & deprecations and comes with a built-in profiler that you can easily hook into to benchmark parts of your own code.
+ +
After learning Symfony’s Form component, I’d rather not go without it again. It makes it trivial to render an accessible form that can be re-used in several places, validating the form upon submit and then populating a PHP object from the form data safely.
+ +$user = $this->getUser();
+$form = $this->createForm(UserBillingInfoType::class, $user)
+ ->handleRequest($request);
+
+if ($form->isSubmitted() && $form->isValid()) {
+ // $user is already populated with the form values at this point
+ // it's valid, so we can update the database and redirect the user now
+}
+Doctrine is another piece of software that really improved our overall application. Your models (entities) are normal PHP classes and relations (associations) are normal references, making it easy to test your domain logic without having to worry about the database implementation.
+ +$user = new User();
+$user->addLicense(new License());
+$manager->persist($user); // both user and its license will be saved
+In Doctrine all operations are wrapped in a SQL transaction by default. That’s a big plus for me as it guarantees atomicity, which involved more work to get right in Eloquent.
+ +Go is (still) great
+ +Honestly, Go is great. Its simplicity is refreshing and you can’t get anywhere near that kind of performance using PHP 1. I would still pick it if we need a small API or something that requires high throughput.
+ +Our shops however are more monolithic with a lot of server-side rendering. While that’s certainly doable in Go (as the last 2 years proved), it’s more maintainable for us to do it in PHP right now.
+ +++ +Side note: without the experience gained from our years on Go, I probably wouldn’t have started Fathom. So perhaps it wasn’t such a bad business decision after all?
+
Making the correct business decision
+ +One reason not mentioned so far is that over the last year or so, I’ve been approached by several companies interested to take over one of our products.
+ +They were a little surprised to hear our stack involved Golang and some flat out told us they’d prefer PHP, because that’s what most of our products (mc4wp.com, boxzillaplugin.com and htmlformsplugin.com) rely upon. And I don’t blame them.
+ ++ +
1 Just for fun, I compared apples and oranges again by benchmarking the login page (which doesn't hit any database) for both application versions using Siege.
+ +The Symfony application (PHP 7.3, OPcache enabled, optimized autoloader) handles about 1470 req/s. The Go application (compiled using Go v1.11) averages about 18600 req/s.
+ + +
+
+ ING, patrocinador Gold del FrontFest 2019
+FrontFest 03 02 2019
+
+
+ ¿Conoces The Cocktail? Es patrocinador del Frontfest 2019
+FrontFest 02 02 2019
+
+
+ OOP Before OOP with Simula
+Two-Bit History 31 01 2019
+
+ 
+
+
+ Code Entropy
+MonkeyUser 29 01 2019
+
+
+ My Story: How to Accidentally Self-Publish a Book
+Jovica Ilic 26 01 2019
+Intro This is the first part of a post which will guide you through the entire process of writing and self publishing a book for the first time. It’s about my book called Mastering Vim Quickly: From WTF to OMG in no time. The idea Vim is a very powerful text editor, used mainly by sysadmins,... Continue reading
+The post My Story: How to Accidentally Self-Publish a Book appeared first on Jovica Ilic.
+ +
+
+ Q1 2019 Funding Announcement
+News on Clojurists Together 23 01 2019
+
+
+ Gray streams
+Lisp journey 22 01 2019
+This is a copy of http://www.nhplace.com/kent/CL/Issues/stream-definition-by-user.html with syntax highlighting.
+ +FAILED Issue STREAM-DEFINITION-BY-USER (“Gray Streams”)
+ +This is the writeup of failed issue STREAM-DEFINITION-BY-USER. Because it did not pass, it has no official standing other than as a historical document.
+ +NOTES:
+ +-
+
Several vendors have implemented this proposal anyway, so if you’d like to use this facility, you might check to see if it’s available in your implementation of choice in spite of not being part the “official” standard.
+
+The facility described here is commonly referred to as “Gray Streams”, after David Gray, who wrote the proposal—please do not write this as “Grey Streams”!
+
+Another facility of note that came later and may be available in some implementations is Franz’s “Simple Streams”. It is newer and addresses a broader range of issues, but its availability in this or that implementation may be different.
+
Click here to see my personal notes on this issue. +–Kent Pitman (10-Mar-2001)
+ +Issue: STREAM-DEFINITION-BY-USER
+ +References: CLtL pages 329-332, 378-381, and 384-385.
+ +Related issues: STREAM-INFO, CLOSED-STREAM-FUNCTIONS, STREAM-ACCESS, + STREAM-CAPABILITIES
+ +Category: ADDITION
+ +Edit history: Version 1, 22-Mar-89 by David N. Gray
+ +Status: For discussion and evaluation; not proposed for + inclusion in the standard at this time.
+ + + +Table of Contents
+ +-
+
- Problem description +
- Proposal
stream-definition-by-user:generic-functions+ +
+ - Rationale +
- Current practice +
- Examples +
- Cost to Implementors +
- Cost to Users +
- Cost of non-adoption +
- Performance impact +
- Benefits +
- Esthetics +
- Discussion +
Problem description
+ +Common Lisp does not provide a standard way for users to define their + own streams for use by the standard I/O functions. This impedes the + development of window systems for Common Lisp because, while there are + standard Common Lisp I/O functions and there are beginning to be + standard window systems, there is no portable way to connect them + together to make a portable Common Lisp window system.
+ +There are also many applications where users might want to define + their own filter streams for doing things like printer device control, + report formatting, character code translation, or + encryption/decryption.
+ +Proposal stream-definition-by-user:generic-functions
+
+Overview
+ +Define a set of generic functions for performing I/O. These functions + will have methods that specialize on the stream argument; they would + be used by the existing I/O functions. Users could write additional + methods for them in order to support their own stream classes.
+ +Define a set of classes to be used as the superclass of a stream class + in order to provide some default methods.
+ +## Classes
+ +The following classes are to be used as super classes of user-defined + stream classes. They are not intended to be directly instantiated; they + just provide places to hang default methods.
+ +fundamental-stream [Class]
This class is a subclass of `stream` and of `standard-object`. `streamp`
+will return true for an instance of any class that includes this. (It
+may return true for some other things also.)
+fundamental-input-stream [Class]
A subclass of `fundamental-stream`. Its inclusion causes `input-stream-p`
+to return true.
+fundamental-output-stream [Class]
A subclass of `fundamental-stream`. Its inclusion causes `output-stream-p`
+to return true. Bi-direction streams may be formed by including both
+`fundamental-output-stream` and `fundamental-input-stream`.
+fundamental-character-stream [Class]
A subclass of `fundamental-stream`. It provides a method for
+`stream-element-type` which returns `character`.
+fundamental-binary-stream [Class]
A subclass of `fundamental-stream`. Any instantiable class that
+includes this needs to define a method for `stream-element-type`.
+fundamental-character-input-stream [Class]
Includes `fundamental-input-stream` and `fundamental-character-stream`.
+It provides default methods for several generic functions used for
+character input.
+fundamental-character-output-stream [Class]
Includes `fundamental-output-stream` and `fundamental-character-stream`.
+It provides default methods for several generic functions used for
+character output.
+fundamental-binary-input-stream [Class]
Includes `fundamental-input-stream` and `fundamental-binary-stream`.
+fundamental-binary-output-stream [Class]
Includes `fundamental-output-stream` and `fundamental-binary-stream`.
+Character input
+ +A character input stream can be created by defining a class that
+ includes fundamental-character-input-stream and defining methods for the
+ generic functions below.
stream-read-char stream [Generic Function]
This reads one character from the stream. It returns either a
+character object, or the symbol :EOF if the stream is at end-of-file.
+Every subclass of `fundamental-character-input-stream` must define a
+method for this function.
+
+Note that for all of these generic functions, the stream argument
+must be a stream object, not T or NIL.
+stream-unread-char stream character [Generic Function]
Un-does the last call to `stream-read-char`, as in `unread-char`. Returns
+NIL. Every subclass of `fundamental-character-input-stream` must define
+a method for this function.
+stream-read-char-no-hang stream [Generic Function]
This is used to implement `read-char-no-hang`. It returns either a
+character, or NIL if no input is currently available, or :EOF if
+end-of-file is reached. The default method provided by
+`fundamental-character-input-stream` simply calls `stream-read-char`; this
+is sufficient for file streams, but interactive streams should define
+their own method.
+stream-peek-char stream [Generic Function]
Used to implement `peek-char`; this corresponds to peek-type of NIL.
+It returns either a character or :EOF. The default method
+calls `stream-read-char` and `stream-unread-char`.
+stream-listen stream [Generic Function]
Used by `listen`. Returns true or false. The default method uses
+`stream-read-char-no-hang` and `stream-unread-char`. Most streams should
+define their own method since it will usually be trivial and will
+always be more efficient than the default method.
+stream-read-line stream [Generic Function]
Used by `read-line`. A string is returned as the first value. The
+second value is true if the string was terminated by end-of-file
+instead of the end of a line. The default method uses repeated
+calls to `stream-read-char`.
+stream-clear-input stream [Generic Function]
Implements `clear-input` for the stream, returning NIL. The default
+method does nothing.
+Character output
+ +A character output stream can be created by defining a class that
+ includes fundamental-character-output-stream and defining methods for the
+ generic functions below.
stream-write-char stream character [Generic Function]
Writes character to the stream and returns the character. Every
+subclass of `fundamental-character-output-stream` must have a method
+defined for this function.
+stream-line-column stream [Generic Function]
This function returns the column number where the next character
+will be written, or NIL if that is not meaningful for this stream.
+The first column on a line is numbered 0. This function is used in
+the implementation of `pprint` and the FORMAT ~T directive. For every
+character output stream class that is defined, a method must be
+defined for this function, although it is permissible for it to
+always return NIL.
+stream-start-line-p stream [Generic Function]
This is a predicate which returns T if the stream is positioned at the
+beginning of a line, else NIL. It is permissible to always return
+NIL. This is used in the implementation of `fresh-line`. Note that
+while a value of 0 from `stream-line-column` also indicates the
+beginning of a line, there are cases where `stream-start-line-p` can be
+meaningfully implemented although `stream-line-column` can't be. For
+example, for a window using variable-width characters, the column
+number isn't very meaningful, but the beginning of the line does have
+a clear meaning. The default method for `stream-start-line-p` on class
+`fundamental-character-output-stream` uses `stream-line-column`, so if
+that is defined to return `nil`, then a method should be provided for
+either `stream-start-line-p` or `stream-fresh-line`.
+stream-write-string stream string &optional start end [Generic Function]
This is used by `write-string`. It writes the string to the stream,
+optionally delimited by start and end, which default to 0 and NIL.
+The string argument is returned. The default method provided by
+`fundamental-character-output-stream` uses repeated calls to
+`stream-write-char`.
+stream-terpri stream [Generic Function]
Writes an end of line, as for `terpri`. Returns NIL. The default
+method does (`stream-write-char` stream #\NEWLINE).
+stream-fresh-line stream [Generic Function]
Used by `fresh-line`. The default method uses `stream-start-line-p` and
+`stream-terpri`.
+stream-finish-output stream [Generic Function]
Implements `finish-output`. The default method does nothing.
+stream-force-output stream [Generic Function]
Implements `force-output`. The default method does nothing.
+stream-clear-output stream [Generic Function]
Implements `clear-output`. The default method does nothing.
+stream-advance-to-column stream column [Generic Function]
Writes enough blank space so that the next character will be written
+at the specified column. Returns true if the operation is
+successful, or NIL if it is not supported for this stream.
+This is intended for use by by `pprint` and FORMAT ~T. The default
+method uses `stream-line-column` and repeated calls to
+`stream-write-char` with a #\SPACE character; it returns NIL if
+`stream-line-column` returns NIL.
+## Other functions
+ +close stream &key abort [Generic Function]
The existing function `close` is redefined to be a generic function, but
+otherwise behaves the same. The default method provided by class
+`fundamental-stream` sets a flag for `open-stream-p`. The value returned
+by `close` will be as specified by the issue `closed-stream-operations`.
+open-stream-p stream [Generic Function]
This function [from proposal `stream-access]` is made generic. A
+default method is provided by class `fundamental-stream` which returns
+true if `close` has not been called on the stream.
+streamp object [Generic Function]
input-stream-p stream [Generic Function]
output-stream-p stream [Generic Function]
These three existing predicates may optionally be implemented as
+generic functions for implementations that want to permit users to
+define streams that are not `standard-object`s. Normally, the default
+methods provided by classes `fundamental-input-stream` and
+`fundamental-output-stream` are sufficient. Note that, for example,
+(INPUT-STREAM-P x) is not equivalent to (TYPEP x
+'FUNDAMENTAL-INPUT-STREAM) because implementations may have
+additional ways of defining their own streams even if they don't
+make that visible by making these predicates generic.
+stream-element-type stream [Generic Function]
This existing function is made generic, but otherwise behaves the
+same. Class `fundamental-character-stream` provides a default method
+which returns `character`.
+pathname and truename are also permitted to be implemented as generic
+ functions. There is no default method since these are not valid for
+ all streams.
## Binary streams:
+ +Binary streams can be created by defining a class that includes either
+`fundamental-binary-input-stream` or `fundamental-binary-output-stream`
+(or both) and defining a method for `stream-element-type` and for one or
+both of the following generic functions.
+stream-read-byte stream [Generic Function]
Used by `read-byte`; returns either an integer, or the symbol :EOF if the
+stream is at end-of-file.
+stream-write-byte stream integer [Generic Function]
Implements `write-byte`; writes the integer to the stream and returns
+the integer as the result.
+Rationale
+ +The existing I/O functions cannot be made generic because, in nearly
+ every case, the stream argument is optional, and therefore cannot be
+ specialized. Therefore, it is necessary to define a lower-level
+ generic function to be used by the existing function. It also isn’t
+ appropriate to specialize on the second argument of print-object because
+ it is a higher-level function – even when the first argument is a
+ character or a string, it needs to format it in accordance with
+ *PRINT-ESCAPE*.
In order to make the meaning as obvious as possible, the names of the
+ generic functions have been formed by prefixing “stream-” to the
+ corresponding non-generic function.
Having the generic input functions just return :EOF at end-of-file, with + the higher-level functions handling the eof-error-p and eof-value + arguments, simplifies the generic function interface and makes it more + efficient by not needing to pass through those arguments. Note that the + functions that use this convention can only return a character or + integer as a stream element, so there is no possibility of ambiguity.
+ +Functions stream-line-column, stream-start-line-p, and
+ stream-advance-to-column may appear to be a reincarnation of the
+ defeated proposal stream-info, but the motivation here is different.
+ This interface needs to be defined if user-defined streams are to be
+ able to be used by pprint and FORMAT ~T, which could be viewed as a
+ separate question from whether the user can call then on
+ system-defined streams.
Current practice
+ +No one currently supports exactly this proposal, but this is very
+ similar to the stream interface used in clue.
On descendants of the MIT Lisp Machine, streams can be implemented + by users as either flavors, with methods to accept the various + messages corresponding to the I/O operations, or as functions, which + take a message keyword as their first argument.
+ +Examples
+ + ;;;; Here is an example of how the default methods could be
+ ;;;; implemented (omitting the most trivial ones):
+
+ (defmethod STREAM-PEEK-CHAR ((stream fundamental-character-input-stream))
+ (let ((character (stream-read-char stream)))
+ (unless (eq character :eof)
+ (stream-unread-char stream character))
+ character))
+
+ (defmethod STREAM-LISTEN ((stream fundamental-character-input-stream))
+ (let ((char (stream-read-char-no-hang stream)))
+ (and (not (null char))
+ (not (eq char :eof))
+ (progn (stream-unread-char stream char) t))))
+
+ (defmethod STREAM-READ-LINE ((stream fundamental-character-input-stream))
+ (let ((line (make-array 64 :element-type 'string-char
+ :fill-pointer 0 :adjustable t)))
+ (loop (let ((character (stream-read-char stream)))
+ (if (eq character :eof)
+ (return (values line t))
+ (if (eql character #\newline)
+ (return (values line nil))
+ (vector-push-extend character line)))))))
+
+ (defmethod STREAM-START-LINE-P ((stream fundamental-character-output-stream))
+ (equal (stream-line-column stream) 0))
+
+ (defmethod STREAM-WRITE-STRING ((stream fundamental-character-output-stream)
+ string &optional (start 0)
+ (end (length string)))
+ (do ((i start (1+ i)))
+ ((>= i end) string)
+ (stream-write-char stream (char string i))))
+
+ (defmethod STREAM-TERPRI ((stream fundamental-character-output-stream))
+ (stream-write-char stream #\newline)
+ nil)
+
+ (defmethod STREAM-FRESH-LINE ((stream fundamental-character-output-stream))
+ (if (stream-start-line-p stream)
+ nil
+ (progn (stream-terpri stream) t)))
+
+ (defmethod STREAM-ADVANCE-TO-COLUMN ((stream fundamental-character-output-stream)
+ column)
+ (let ((current (stream-line-column stream)))
+ (unless (null current)
+ (dotimes (i (- current column) t)
+ (stream-write-char stream #\space)))))
+
+ (defmethod INPUT-STREAM-P ((stream fundamental-input-stream)) t)
+ (defmethod INPUT-STREAM-P ((stream fundamental-output-stream))
+ ;; allow the two classes to be mixed in either order
+ (typep stream 'fundamental-input-stream))
+ (defmethod OUTPUT-STREAM-P ((stream fundamental-output-stream)) t)
+ (defmethod OUTPUT-STREAM-P ((stream fundamental-input-stream))
+ (typep stream 'fundamental-output-stream))
+
+ ;;;; Following is an example of how the existing I/O functions could
+ ;;;; be implemented using standard Common Lisp and the generic
+ ;;;; functions specified above. The standard functions being defined
+ ;;;; are in upper case.
+
+ ;; Internal helper functions
+
+ (proclaim '(inline decode-read-arg decode-print-arg check-for-eof))
+ (defun decode-read-arg (arg)
+ (cond ((null arg) *standard-input*)
+ ((eq arg t) *terminal-io*)
+ (t arg)))
+
+ (defun decode-print-arg (arg)
+ (cond ((null arg) *standard-output*)
+ ((eq arg t) *terminal-io*)
+ (t arg)))
+
+ (defun check-for-eof (value stream eof-errorp eof-value)
+ (if (eq value :eof)
+ (report-eof stream eof-errorp eof-value)
+ value))
+
+ (defun report-eof (stream eof-errorp eof-value)
+ (if eof-errorp
+ (error 'end-of-file :stream stream)
+ eof-value))
+
+ ;;; Common Lisp input functions
+
+ (defun READ-CHAR (&optional input-stream (eof-errorp t) eof-value recursive-p)
+ (declare (ignore recursive-p)) ; a mistake in CLtL?
+ (let ((stream (decode-read-arg input-stream)))
+ (check-for-eof (stream-read-char stream) stream eof-errorp eof-value)))
+
+ (defun PEEK-CHAR (&optional peek-type input-stream (eof-errorp t)
+ eof-value recursive-p)
+ (declare (ignore recursive-p))
+ (let ((stream (decode-read-arg input-stream)))
+ (if (null peek-type)
+ (check-for-eof (stream-peek-char stream) stream eof-errorp eof-value)
+ (loop
+ (let ((value (stream-peek-char stream)))
+ (if (eq value :eof)
+ (return (report-eof stream eof-errorp eof-value))
+ (if (if (eq peek-type t)
+ (not (member value '(#\space #\tab #\newline
+ #\page #\return #\linefeed)))
+ (char= peek-type value))
+ (return value)
+ (stream-read-char stream))))))))
+
+ (defun UNREAD-CHAR (character &optional input-stream)
+ (stream-unread-char (decode-read-arg input-stream) character))
+
+ (defun LISTEN (&optional input-stream)
+ (stream-listen (decode-read-arg input-stream)))
+
+ (defun READ-LINE (&optional input-stream (eof-error-p t)
+ eof-value recursive-p)
+ (declare (ignore recursive-p))
+ (let ((stream (decode-read-arg input-stream)))
+ (multiple-value-bind (string eofp)
+ (stream-read-line stream)
+ (if eofp
+ (if (= (length string) 0)
+ (report-eof stream eof-error-p eof-value)
+ (values string t))
+ (values string nil)))))
+
+ (defun CLEAR-INPUT (&optional input-stream)
+ (stream-clear-input (decode-read-arg input-stream)))
+
+ (defun READ-CHAR-NO-HANG (&optional input-stream (eof-errorp t)
+ eof-value recursive-p)
+ (declare (ignore recursive-p))
+ (let ((stream (decode-read-arg input-stream)))
+ (check-for-eof (stream-read-char-no-hang stream)
+ stream eof-errorp eof-value)))
+
+ ;;; Common Lisp output functions
+
+ (defun WRITE-CHAR (character &optional output-stream)
+ (stream-write-char (decode-print-arg output-stream) character))
+
+ (defun FRESH-LINE (&optional output-stream)
+ (stream-fresh-line (decode-print-arg output-stream)))
+
+ (defun TERPRI (&optional output-stream)
+ (stream-terpri (decode-print-arg output-stream)))
+
+ (defun WRITE-STRING (string &optional output-stream &key (start 0) end)
+ (stream-write-string (decode-print-arg output-stream) string start end))
+
+ (defun WRITE-LINE (string &optional output-stream &key (start 0) end)
+ (let ((stream (decode-print-arg output-stream)))
+ (stream-write-string stream string start end)
+ (stream-terpri stream)
+ string))
+
+ (defun FORCE-OUTPUT (&optional stream)
+ (stream-force-output (decode-print-arg stream)))
+
+ (defun FINISH-OUTPUT (&optional stream)
+ (stream-finish-output (decode-print-arg stream)))
+
+ (defun CLEAR-OUTPUT (&optional stream)
+ (stream-clear-output (decode-print-arg stream)))
+
+ ;;; Binary streams
+
+ (defun READ-BYTE (binary-input-stream &optional (eof-errorp t) eof-value)
+ (check-for-eof (stream-read-byte binary-input-stream)
+ binary-input-stream eof-errorp eof-value))
+
+ (defun WRITE-BYTE (integer binary-output-stream)
+ (stream-write-byte binary-output-stream integer))
+
+ ;;; String streams
+
+ (defclass string-input-stream (fundamental-character-input-stream)
+ ((string :initarg :string :type string)
+ (index :initarg :start :type fixnum)
+ (end :initarg :end :type fixnum)
+ ))
+
+ (defun MAKE-STRING-INPUT-STREAM (string &optional (start 0) end)
+ (make-instance 'string-input-stream :string string
+ :start start :end (or end (length string))))
+
+ (defmethod stream-read-char ((stream string-input-stream))
+ (with-slots (index end string) stream
+ (if (>= index end)
+ :eof
+ (prog1 (char string index)
+ (incf index)))))
+
+ (defmethod stream-unread-char ((stream string-input-stream) character)
+ (with-slots (index end string) stream
+ (decf index)
+ (assert (eql (char string index) character))
+ nil))
+
+ (defmethod stream-read-line ((stream string-input-stream))
+ (with-slots (index end string) stream
+ (let* ((endline (position #\newline string :start index :end end))
+ (line (subseq string index endline)))
+ (if endline
+ (progn (setq index (1+ endline))
+ (values line nil))
+ (progn (setq index end)
+ (values line t))))))
+
+ (defclass string-output-stream (fundamental-character-output-stream)
+ ((string :initform nil :initarg :string)))
+
+ (defun MAKE-STRING-OUTPUT-STREAM ()
+ (make-instance 'string-output-stream))
+
+ (defun GET-OUTPUT-STREAM-STRING (stream)
+ (with-slots (string) stream
+ (if (null string)
+ ""
+ (prog1 string (setq string nil)))))
+
+ (defmethod stream-write-char ((stream string-output-stream) character)
+ (with-slots (string) stream
+ (when (null string)
+ (setq string (make-array 64. :element-type 'string-char
+ :fill-pointer 0 :adjustable t)))
+ (vector-push-extend character string)
+ character))
+
+ (defmethod stream-line-column ((stream string-output-stream))
+ (with-slots (string) stream
+ (if (null string)
+ 0
+ (let ((nx (position #\newline string :from-end t)))
+ (if (null nx)
+ (length string)
+ (- (length string) nx 1))
+ ))))
+Cost to Implementors
+ +Given that CLOS is supported, adding the above generic functions and + methods is easy, since most of the code is included in the examples + above. The hard part would be re-writing existing I/O functionality in + terms of methods on these new generic functions. That could be + simplified if methods can be defined to forward the operations to the + old representation of streams. For a new implementation, the cost could + be zero since an approach similar to this would likely be used anyway.
+ +Cost to Users
+ +None; this is an upward-compatible addition. Users won’t even + need to know anything about this unless they actually need this feature.
+ +Cost of non-adoption
+ +Development of portable I/O extensions will be discouraged.
+ +Performance impact
+ +This shouldn’t affect performance of new implementations (assuming an + efficient CLOS implementation), but it could slow down I/O if it were + clumsily grafted on top of an existing implementation.
+ +Benefits
+ +A broader domain of programs that can be written portably.
+ +Esthetics
+ +This seems to be a simple, straight-forward approach.
+ +Discussion
+ +This proposal incorporates suggestions made by several people in
+ response to an earlier outline. So far, no one has expressed opposition
+ to the concept. There are some differences of opinion about whether
+ certain operations should have default methods or required methods:
+ stream-listen, stream-read-char-no-hang, stream-line-column,
+ and stream-start-line-p.
An experimental prototype of this has been successfully implemented on + the Explorer.
+ +This proposal does not provide sufficient capability to implement
+ forwarding streams such as for make-synonym-stream,
+ make-broadcast-stream, make-concatenated-stream, make-two-way-stream, or
+ make-echo-stream. The generic function approach does not lend itself as
+ well to that as a message passing model where the intermediary does not
+ need to know what all the possible messages are. A possible way of
+ extending it for that would be to define a class
(defclass stream-generic-function (standard-generic-function) ())
+to be used as the :generic-function-class option for all of the I/O + generic functions. This would then permit doing something like
+ + (defmethod no-applicable-method ((gfun stream-generic-function) &rest args)
+ (if (streamp (first args))
+ (apply #'stream-operation-not-handled (first args) gfun (rest args))
+ (call-next-method)))
+where stream-operation-not-handled is a generic function whose default
+ method signals an error, but forwarding streams can define methods that
+ will create a method to handle the unexpected operation. (Perhaps
+ no-applicable-method should be changed to take two required arguments
+ since all generic functions need at least one required argument, and
+ that would make it unnecessary to define a new generic function class
+ just to be able to write this one method.)
Another thing that is not addressed here is a way to cause an instance
+ of a user-defined stream class to be created from a call to the open
+ function. That should be part of a separate issue for generic functions
+ on pathnames. If that capability were available, then pathname and
+ truename should be required to be generic functions.
An earlier draft defined just two classes, fundamental-input-stream and
+ fundamental-output-stream, that were used for both character and binary
+ streams. It isn’t clear whether that simple approach is sufficient or
+ whether the larger set of classes is really needed.
+ 
+
+
+ Meeting
+MonkeyUser 22 01 2019
+
+
+ Running Luminus on Dokku
+(iterate think thoughts) 19 01 2019
+Luminus provides a great way to get up and running with a Clojure web application. However, building your app is only half the work. Once you've got your app working, the next step is to host it somewhere so that the users can access it.
Cloud platforms, such as AWS, are a popular choice for deploying large scale solutions. On the other hand, VPS services like Digital Ocean and Linode provide a more economical alternative for small scale applications. The downside of running your own VPS is that managing it can be labor intensive. This is where Dokku comes in. It's a private PaaS modelled on Heroku that you can use to provision a VPS.
Let's take a look at what's involved in provisioning a Digital Ocean droplet with Dokku and deploying a Luminus web app to it.
Set up the server
Let's create a droplet with Ubuntu LTS (18.0.4 at the time of writing) and SSH into it. We'll need to add new APT repositories before we install Dokku.
- add the universe repository
sudo add-apt-repository universe - add the key
wget -nv -O - https://packagecloud.io/dokku/dokku/gpgkey | apt-key add - - add the Dokku repo
echo "deb https://packagecloud.io/dokku/dokku/ubuntu/ bionic main" > /etc/apt/sources.list.d/dokku.list
Once the repositories are added, we'll need to update the dependencies and install Dokku.
- update dependencies
sudo apt-get update && sudo apt-get upgrade - install dokku
apt-get install dokku
Once Dokku is installed, we'll create an application and a Postgres database instance.
- create the app
dokku apps:create myapp - install dokku-postgres plugin
sudo dokku plugin:install https://github.com/dokku/dokku-postgres.git - create the db
dokku postgres:create mydb - link the db to the app
dokku postgres:link mydb myapp
We're now ready to deploy the app.
Create a new Luminus application
Let's create a Luminus application on your local machine.
lein new luminus myapp +postgrescd myapp
Let's update the app to run migrations on startup by updating the myapp.core/start-app function to run the migrations.
(defn start-app [args]
+ (doseq [component (-> args
+ (parse-opts cli-options)
+ mount/start-with-args
+ :started)]
+ (log/info component "started"))
+
+ ;;run migrations
+ (migrations/migrate ["migrate"] (select-keys env [:database-url]))
+
+ (.addShutdownHook (Runtime/getRuntime) (Thread. stop-app)))
+Next, we need to update env/prod/resources/logback.xml to use STDOUT for the logs:
<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+ <statusListener class="ch.qos.logback.core.status.NopStatusListener" />
+ <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+ <!-- encoders are assigned the type
+ ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
+ <encoder>
+ <charset>UTF-8</charset>
+ <pattern>%date{ISO8601} [%thread] %-5level %logger{36} - %msg %n</pattern>
+ </encoder>
+ </appender>
+ <logger name="org.apache.http" level="warn" />
+ <logger name="org.xnio.nio" level="warn" />
+ <logger name="com.zaxxer.hikari" level="warn" />
+ <root level="INFO">
+ <appender-ref ref="STDOUT" />
+ </root>
+</configuration>
+Deploy the application to Dokku
We're now ready to deploy the app. First, we'll need to create a Git repo and add the app contents to it.
git initgit add .gitignore Procfile project.clj README.md src/* env/* test/* resources/*git commit -a -m "initial commit"
Note that you do not want to check in Dockerfile that's generated by the template. Dokku will use it as the preferred strategy for creating the container.
Next, we'll add the remote for the Dokku repository on the server and push the project to the remote. Dokku will automatically build the project once it's pushed, and deploy the application when the build is successful.
git remote add dokku dokku@<server name>:myappgit push dokku master
The app will be pushed to the server where it will be compiled and run. If everything went well you should see output that looks something like the following:
...
+-----> Building with Leiningen
+ Running: lein uberjar
+ Compiling sample.app
+ 2019-01-18 01:10:30.857:INFO::main: Logging initialized @6674ms to org.eclipse.jetty.util.log.StdErrLog
+ Created /tmp/build/target/myapp-1.0.1.jar
+ Created /tmp/build/target/myapp.jar
+...
+=====> web=1
+...
+-----> Waiting for 10 seconds ...
+-----> Default container check successful!
+-----> Running post-deploy
+-----> Configuring myapp.<server name>...(using built-in template)
+-----> Creating http nginx.conf
+-----> Running nginx-pre-reload
+ Reloading nginx
+-----> Setting config vars
+ DOKKU_APP_RESTORE: 1
+=====> 8dc31ac11011111117f71e4311111ca5962cf316411d5f0125e87bbac26
+=====> Application deployed:
+ http://myapp.<server name>
+
+To http://<server name>:myapp
+ 6dcab39..1c0c8b7 master -> master
+We can check the status of the application in the logs by running dokku logs myapp command on the server. The output should looks something like the following.
Picked up JAVA_TOOL_OPTIONS: -Xmx300m -Xss512k -XX:CICompilerCount=2 -Dfile.encoding=UTF-8
+2019-01-19 19:09:48,258 [main] INFO myapp.env -
+-=[myapp started successfully]=-
+2019-01-19 19:09:50,490 [main] INFO luminus.http-server - starting HTTP server on port 5000
+2019-01-19 19:09:50,628 [main] INFO org.xnio - XNIO version 3.3.6.Final
+2019-01-19 19:09:51,236 [main] INFO org.projectodd.wunderboss.web.Web - Registered web context /
+2019-01-19 19:09:51,242 [main] INFO myapp.core - #'myapp.config/env started
+2019-01-19 19:09:51,243 [main] INFO myapp.core - #'myapp.db.core/*db* started
+2019-01-19 19:09:51,243 [main] INFO myapp.core - #'myapp.handler/init-app started
+2019-01-19 19:09:51,244 [main] INFO myapp.core - #'myapp.handler/app started
+2019-01-19 19:09:51,249 [main] INFO myapp.core - #'myapp.core/http-server started
+2019-01-19 19:09:51,249 [main] INFO myapp.core - #'myapp.core/repl-server started
+2019-01-19 19:09:51,250 [main] INFO myapp.core - running migrations
+2019-01-19 19:09:51,257 [main] INFO migratus.core - Starting migrations
+2019-01-19 19:09:51,418 [main] INFO migratus.database - creating migration table 'schema_migrations'
+2019-01-19 19:09:51,992 [main] INFO migratus.core - Running up for [20190118214013]
+2019-01-19 19:09:51,997 [main] INFO migratus.core - Up 20190118214013-add-users-table
+2019-01-19 19:09:52,099 [main] INFO migratus.core - Ending migrations
+You should now be able to check your application in the browser by navigating to http://<server name>.
Troubleshooting the database
The startup logs for the application indicate that it was able to connect to the database and run the migrations successfully. Let's confirm this is the case by connecting a psql shell to the database container on the server.
dokku postgres:connect mydb
+mydb=# \d
+ List of relations
+ Schema | Name | Type | Owner
+--------+-------------------+-------+----------
+ public | schema_migrations | table | postgres
+ public | users | table | postgres
+(2 rows)
+We can see that the database contains the schema_migrations table and the users table that were created when the app migrations ran.
Sometimes it might be useful to connect a more advanced client such as DBeaver. This can done by exposing the database on the server using the following command.
sudo dokku postgres:expose mydb 5000
+Next, we'll enter the container for the application to get the database connection details.
dokku enter myapp web
+echo $DATABASE_URL
+The DATABASE_URL environment variable in the container will contain the connection string that looks as follows.
postgres://postgres:<password>@dokku-postgres-mydb:5432/mydb
+We can now map the port to the local machine using SSH, and connect to the database as if it was running on the local machine using the connection settings above.
ssh -L 5432:localhost:5000 <server name>
+Set up HTTPS using Let's Encrypt
As the last step we'll set up HTTPS for the application using dokku-letsencrypt plugin. We'll set the app to run on the root domain on the server.
- add the root domain to the app
dokku domains:add myapp <server name> - remove the subdomain from the app
dokku domains:remove myapp myapp.<server name> - install the plugin
sudo dokku plugin:install https://github.com/dokku/dokku-letsencrypt.git - set the email for renewal warnings
dokku config:set --no-restart myapp DOKKU_LETSENCRYPT_EMAIL=<your email> - add HTTPS to the app
sudo dokku letsencrypt myapp - set up auto-renew for the certificate
dokku letsencrypt:auto-renew
That's all there is to it. The application is now deployed to the droplet, it's hooked up to the database, and it's using Let's Encrypt SSL/TLS Certificates.
Any further updates to the application simply involve committing the changes to the local Git repo and pushing them to the server as we did with our initial deploy.
I recommend taking look at the official documentation on the Dokku site for more information about Dokku. I think it provides an excellent solution for running your VPS. If you're evaluating different options for deploying your Clojure apps give Dokku a look.
+
+
+ December 2018 Monthly Update
+News on Clojurists Together 16 01 2019
+
+
+ These Months in Common Lisp Q4 2018
+Lisp journey 15 01 2019
+I wanted to do this for a year and here we are ! I don’t think I’ll +carry on, with this format at least.
+ +If I missed anything crucial: you have comments and PRs: https://gitlab.com/lisp-journey/lisp-journey.gitlab.io/
+ +Happy (re)discoveries !
+ +Documentation
+ +-
+
- Debugging – the Common Lisp Cookbook +
- Loop, iteration, mapping – the Common Lisp Cookbook +
- cl-exercise: Common Lisp Learning System running on browsers +
Announcements
+ +-
+
- various SBCL releases (from 1.4.13 to 1.4.15) (not many changes you think ?) +
- Release of Corman Lisp 3.1 (Windows), with personal notes (also this thread) +
- European Lisp Symposium 2019 - Call for Papers +
- Dandelion, Eclipse IDE plugin, updated for SBCL 1.4.10 +
- December Quicklisp update, october +
- Common Lisp is now available to use at Kattis +
Projects
+ +-
+
- CANDO - A Computational Chemistry programming environment integrating Common Lisp and C++ based on the Jupyter notebook +
- Coalton, a dialect of ML embedded in Common Lisp (alpha) +
- Ulubis - A Wayland compositor written in Common Lisp +
- ISO 8601 date/time library +
- Voxel game engine (Minecraft) +
- magrathea: chaotic-neutral web security for Hunchentoot +
- schannel: Common Lisp Windows SChannel API +
- qbase64: A fast and flexible base64 encoder/decoder in Lisp +
- Beautify Practical Common Lisp, Firefox extension +
- static-dispatch: Static generic function dispatch. The purpose is to provide an optimization in cases where the usual dynamic dispatch is too slow, and the dynamic features are not required +
- cl-http2-protocol: HTTP/2 interop library in Common Lisp +
- cl-punch: Scala-like and CL21-like anonymous lambda literal See other lambda shorthands. +
- Scheme macros for Common Lisp +
- The INVAL plan validator, and other PDDL tools +
- Australian Government statistics collection library +
- Easy local bindings +
- cl-fm - a file manager using cl-cffi-gtk (seems staling. “not ready for prime time”) +
- cl-intervals: Intervals and interval trees for Common Lisp +
GUI:
+ +-
+
- nodgui - yet another Tcl/Tk-based GUI package for Common Lisp +
- YstokWidgets Professional Edition +
- MIDGETS - A collection of CAPI widgets and utilities +
- subtext: A mostly-text-based UI bridges Common Lisp objects and runs of text. Minimal text-based user interface +
Developer utilities:
+ +-
+
- s2i-lisp: Common Lisp + Quicklisp OpenShift Build Image +
- lisp-images: Docker images for common lisp development (with some others, see the awesome-list) +
- Quicklisp.nvim - Common Lisp package management within Neovim +
New releases:
+ +-
+
- JSCL 0.7.0 now supports CLOS thanks to the work of vlad-km +
- Next browser 1.2.0 is out! +
- Lem editor 1.5 released with executables, rust-mode, nim-mode, html-mode, jsx, calc-mode, ncurses for windows, experimental lsp-mode, support for async processes, python and scheme repl and more +
(re)discoveries:
+ +-
+
- cl-rest-server: Serve REST APIs from Common Lisp, Swagger support +
- lfarm - a library for distributing work across machines (on top of lparallel and usocket) +
- cl-docutils: implementation of Docutils. Includes a parser for the reStructured format, writers to html and latex +
- formulador: render math formulas in 2D in your terminal! +
- cl-bibtex: A compatible re-implementation of the BibTeX program in Common Lisp, with a BST-to-CL compiler +
- clcon - a Common Lisp editor (tcl/tk, mostly russian) +
- C language syntax embedded in Common Lisp +
Articles
+ +-
+
- This Old Lisp (on CCL) +
- How the strengths of Lisp-family languages facilitate building complex and flexible bioinformatics applications +
- Writing a natural language date and time parser - internals of the Common Lisp library Chronicity +
- validate-superclass explained +
- CFFI arrays versus STATIC-VECTORS: a comparison +
- Dumping Common Lisp streams +
- Killing Common Lisp methods and classes +
- Funny method combinations +
- Implementing Hunchentoot custom sessions +
- Overview of Documentation Generators (codex, coo, declt, staple, cldomain) +
- Challenging myself to learn Common Lisp in one month +
- Converter of maps from Reflex Arena to QuakeWorld. cl-yacc, 3d-matrices +
- Debugging Common Lisp in Slime +
- Packages in Common Lisp, a tutorial (pdf) +
- How to write test fixtures for FiveAM - Dark Chestnut +
- Franz and Semantic Web Co. Partner to Create a Noam Chomsky Knowledge Graph +
- Composing in Lisp with Csound (see also audio and music composition software) +
- Blogging with Lisp +
- Compiler basics: lisp to assembly +
- Marvin Minsky - Scientist - The beauty of the Lisp language +
GUIs:
+ + + +On games:
+ +-
+
- Baggers responds to ‘Reasons why Lisp games suffer’ +
- About Making Games in Lisp - Gamedev +
- Creating a (Non-Trivial) Lisp Game in 2018 +
Discussion
+ +-
+
- Lisp and the remote agent - with an AMA of Ron Garret +
- How to make (Common) Lisp popular? +
- Feedback from a new LispWorks user (how is LispWorks the company going ?) +
- How do you normally use a program once written ? +
- How does Common Lisp implement hot code reloading? +
- Structs vs Parametric Polymorphism (an answer to the “switching from Common Lisp to Julia - thoughts ?” post) also this discussion +
- How to work on a project and make sure dependencies are tracked correctly? +
- Does anyone else hate LOOP? +
- What does it take to understand the true power of Lisp? +
- How did Lisp make your life easier ? +
- Should local variables be avoided when possible when doing functional programming? +
- Is ABCL an active project and does it support JRE 1.11? +
- Has the Gnu Coreutils ever been implemented in Lisp? If not, would that be a worthwhile project? +
- “Classes are not interactions!” by shka +
Screencasts
+ +-
+
- 2018 LLVM Developers’ Meeting: C. Schafmeister “Lessons Learned Implementing Common Lisp with LLVM” +
- A pile of parens +
- Pushing Pixels with Lisp - 61 - Stenciling (Failed attempt) +
Common Lisp VS …
+ + + +
+ 
+
+
+ Great Expectations
+MonkeyUser 15 01 2019
+
+
+ It's Time to Own My Own Content
+Haki Benita 13 01 2019
+I started writing about two years ago. Back then, I used to read a lot on Medium. When I finally felt the urge to write something, it made sense to publish there as well. Medium provided me with a platform, an audience, and constant reinforcements in the form of stats, likes and comments. It motivated me to keep writing. Despite it's many advantages, I feel Medium is lacking in some areas.
+
+
+ Why Deftask Chose Common Lisp
+Lisp journey 11 01 2019
+We heard about Deftask, a task +management app for teams, a few days ago, in an article about the +internals of the Chronicity library. Deftask +uses Common Lisp for its backend and its command-line app. This +reasonates with the fact that Turtl doesn’t use CL anymore. So I +asked Deftask’s author: why did you go with CL ?
+ ++ +
More than anything else, I think its down to fun and productivity. I +feel that I am at my most productive when I writing CL in Emacs+SLIME. +It is probably down to the edit-compile-debug cycle which is much +shorter in CL compared to other languages. I originally worked on CL +way back in 2006-08 when I was with Cleartrip. Since then, I have +worked on a number of platforms (frontend js, node, iOS, C, Java, +etc.) but always wanted to go back to writing CL full time.
+ +So when I left my last job a little over a year back, I had already +made up my mind that the next thing I build would be in CL.
+ +The lack of libraries (or rather, well supported libraries) is a +problem, but honestly after over eight years of not working on Lisp, +it doesn’t bother me much.
+ +++ +Did you already build software/services in CL, apart +the libraries we can see on your github profile ?
+
As I mentioned I worked at Cleartrip for a little over two years. I +was part of the team that managed the flight search engine, +Unfortunately most of what we did there is gone forever. A small +sliver of our work there resulted in https://lisper.in/restarts +(backstory: https://www.reddit.com/r/lisp/comments/7k85sf/a_tutorial_on_conditions_and_restarts/).
+ +++ +Did you have enough libraries to build your service ? How’s deployment and +maintenance going ?
+
Well you could say I had enough libraries. Although I still ended up +writing a mini web framework on top of Hunchentoot. Another thing I +wrote is my own Lisp-to-SQL converter. Hope to open source both of +these one day. Apart from that I use drakma, postmodern, djula, plump, +lparallel, cl-json to name a few (alongwith the usual suspects like +alexandria and local-time).
+ +Deployment and maintenance is extremely simple - I just update the +relevant git branch and restart the service. At some point when the +restarts become costly I might add the ability to reload changed code +in the running service.
+ ++ +
Thanks to him !
+ +Below the backstory from reddit:
+ ++ +
Hey that was written by me! (Aside: I redirected the page to point to the latest version of this post on my new blog)
+ +Fun fact: I wrote this post way back in 2008 while working for an online travel portal. This was based on some actual work we’d done there. At that time, flight travel in India had started to boom. This I think went hand in hand with a bunch of online travel companies (including ours) gaining a lot of momentum.
+ +To be more competitive, a couple of airlines decided that they wanted to introduce new discounted fares much more frequently than they were doing earlier. The only problem was that they were unable to upload their wonky fare rules in the GDS properly, so they started distributing excel sheets to travel agents with manual instructions on how to apply them.
+ +So our business team starts sending these sheets over to us, and initially, the frequency was low so we just manually hard coded these rules. However then they started sending these sheets every week or so which made our life hell. So we asked asked our business team to “translate” the airline’s excel sheets and instructions into a csv, which was subsequently interpreted by a simple rules engine that we wrote.
+ +The only problem? Well, as anyone who’s dealt with manually created CSVs will tell you, there were a lot of errors. This didn’t really help matters much. We then added a couple of restarts to our CSV parser which allowed us to correct these issues interactively. This made life much better for us – it was a lot easier than, say, getting a list of errors in a terminal and switching back and forth between the terminal window and the editor to correct them.
+ +Later on we plonked the CSV parser behind hunchentoot and asked our bizdev guy to upload the file there. A handle-bind around the parser collected all the errors in one go and showed them in a nicely formatted way in the browser (see the last section of the post). And so it was no longer our problem :-)
+ +Eventually these airlines decided they wanted to update fare rules daily. Thankfully our “business rules engine” was upto the task. Due to automatic feedback, our friend in bizdev became an expert at uploading the fare rules as soon as they came in. And for quite some time, we were the only ones who could show these cheap fares within minutes of them coming in (if I remember correctly, other portals would take hours to upload the same rules).
+ +Ours was a small team, and we had to manage this in addition to a lot of other things. If it weren’t for CL’s condition system, I doubt we could have solved this as smoothly as we did. In particular, interactive restarts allowed us (devs) to correct CSV errors without wasting a lot of our own time, and without needing to build a full-fledged UI for a non-dev. And when the time did come for a UI, it was dead easy to write a web fontend on top of it.
+ +++ +Q: Did you ever work or need an optimal solution to the Tavelling Salesman Problem?
+
Nope. Domestic flight travel in India is simple… point to point or max over two legs. For international flights we used QPX.
+ +(QPX was ITA software’s flight search engine. Probably among the biggest software systems written in Lisp. It now powers Google Flights (I think).)
+ ++ +
+
+ Why Turtl Switched From CL to Js
+Lisp journey 11 01 2019
+Turtl is a very well done, secure collaborative notebook web app.
+ + + +Its api backend is built in Common Lisp:
+ + + +It is based on many async libraries the developer wrote for Turtl, +like the Wookie async HTTP +server.
+ +“is” ? No, was :/ Even though this repository is still maintained +(latest commit: 2nd of december 2018), it is deprecated and the +new server is written in NodeJS. I +asked Andrew for the reasons behind this, here’s his answer.
+ +(in a hurry to spread FUD ? Don’t miss this posts’s twin, +Why Deftask chose Common Lisp +;) See also some +companies using Common Lisp)
+ ++ +
It was not an easy decision to replace CL with javascript. I find CL +to be elegant, fast, stable, and above all else, easy to debug (having +the ability to rewrite the program as it’s running is insanely +useful). In fact, I still miss lisp and ask myself all the time if I +made the right choice.
+ +I think I did, though.
+ +The path I went with CL was a hard one. I wanted to be able to use +asynchronous programming because for the type of work I do (a lot of +making APIs that talk to other services with very little CPU work) +it’s hard to get much more performant. So I embarked on creating +cl-async/cl-libuv (originally cl-libevent) and wookie, along with a +few other drivers. Everything I built worked great (and still works +great, as far as I can tell) however when things did go wrong, there +was nobody to run ideas by and nobody to really help me…I had built +all these things myself, and I also had to be responsible for fixing +them when they broke. On top of having to maintain everything (and it +did break from time to time) there is not much in the way of packages +to help me out. For instance, there’s a package to upload files to S3, +but it’s not async at all…I had to build this from scratch. There +are more cases of this as well.
+ +With CL, it felt like I was constantly fighting the tide. I was +constantly battling just to get basic things working that are already +solved problems in other languages (Node).
+ +There was help and support from the community along the way, but I was +mostly fighting it alone. I think the straw that broke the camel’s +back was when a few people started making copycat projects that added +no real value (other than benchmarking fast) but stole mindshare from +all the work I had put in. It was the “well, that project is not +exactly what I want so I’ll make my own from scratch” mindset that +everyone always warned about when I was starting with CL (but I +ignored). I had really hoped the community would have helped propel +the async ecosystem I was building forward, but I just don’t think +there’s enough people using CL for that to happen.
+ +So between having to maintain everything myself and people putting out +worthless copycat projects that ended up going nowhere, I didn’t have +the energy anymore.
+ +Honestly, it took me about a week of work, just nights and weekends, +to reprogram the server in javascript. Granted, most of the “how +should this work?” architecture stuff was already done so it was more +of a rewrite than a build-from-scratch situation, but Node is fast to +build APIs in. I’m decently fluent in javascript and the amount +packages available is so immense that it just made sense.
+ +On top of being fast to build in, it’s a well-traveled road. I don’t +have people emailing me six times a day asking how to install the +server like I did with CL. I don’t have to make weird custom loaders +to run the app on any hosting providers…everyone supports Node. I +don’t have to deal with weird FFI errors or libuv nuances. I don’t +have to deal with quicklisp’s “all or nothing” packaging that doesn’t +support version pinning. I don’t have to restart the server every 20 +days because of some memory leak I have yet to track down somewhere +between cl-libuv, cl-async, wookie, and turtl. There’s a whole set of +bullshit I just don’t have to deal with anymore.
+ +So I do miss lisp. I’d eventually like to build more things in it +(like games). But I don’t think I’ll ever touch web stuff in CL again, +and the whole journey left a bitter taste in my mouth. Sure I could +have dropped the async thing and just done a threaded server in +hunchentoot and cl-postgres. But once I decided I was going to +reprogram everything anyway, it just made sense to go with Node.
+ +I took on more work than I could realistically manage, and hoped that +the community would help…but the CL community is small enough that +it was a losing bet and I got burned out.
+ +Hopefully none of this discourages you. CL is a great language. The +community is a mix though. Some of the people in the community are +smart and dedicated, and work on cool projects at a pace they can +maintain. You won’t see articles about these projects, and many will +only have a handful of stars on Github (don’t measure CL projects by +stars). Seek these projects and these people out, and build things +with them. There is a quiet corner of the internet, with a handful of +people building amazing things in lisp.
+ ++ +
Before commenting on this, I think we must realize what he achieved, +and that he went the hard way.
+ +Now don’t miss Why Deftask chose Common Lisp !
+ +
+
+ Introducing Replic: an executable and a library to build a readline app in no time
+Lisp journey 09 01 2019
+When I started dabbling in CL, I tried to build a readline application +to see how it goes. I found +cl-readline (I’m only the +new maintainer) and it went smoothly. So I built a second and a third +app, and found many things to refactor and provide out of the box: now +comes replic.
+ +It comes as a library (now in Quicklisp, since 2018-01) and as an +executable. The library does the following for you:
+ +-
+
- it builds the repl loop, catches a C-c, a C-d, errors, +
- it asks confirmation to quit, +
- it asks depending on a .conf and a lispy config file, +
- it reads parameters from a config file, +
- it prints the help of all or one command (with optional highlighting), +
- and more importantly it handles the completion of commands and of their arguments. +
For example, instead of this “repl” loop:
+ + (handler-case
+ (do ((i 0 (1+ i))
+ (text "")
+ (verb "")
+ (function nil)
+ (variable nil)
+ (args ""))
+ ((string= "quit" (str:trim text)))
+
+ (handler-case
+ (setf text
+ (rl:readline :prompt (prompt)
+ :add-history t))
+ (#+sbcl sb-sys:interactive-interrupt ()
+ (progn
+ (when (confirm)
+ (uiop:quit)))))
+
+ (if (string= text "NIL")
+ ;; that's a C-d, a blank input is just "".
+ (when (confirm)
+ (uiop:quit)))
+
+ (unless (str:blank? text)
+ (setf verb (first (str:words text)))
+ (setf function (if (replic.completion:is-function verb)
+ ;; might do better than this or.
+ (replic.completion:get-function verb)))
+ (setf variable (if (replic.completion:is-variable verb)
+ (replic.completion:get-variable verb)))
+ (setf args (rest (str:words text)))
+
+
+ (if (and verb function)
+ (handler-case
+ ;; Call the function.
+ (apply function args)
+ (#+sbcl sb-sys:interactive-interrupt (c)
+ (declare (ignore c))
+ (terpri))
+ (error (c) (format t "Error: ~a~&" c)))
+
+ (if variable
+ (format t "~a~&" (symbol-value variable))
+ (format t "No command or variable bound to ~a~&" verb)))
+
+ (finish-output)
+
+ (when (and *history*
+ *write-history*)
+ (rl:write-history "/tmp/readline_history"))
+ ))
+
+ (error (c)
+ (format t "~&Unknown error: ~&~a~&" c)))
+you call:
+ +(replic:repl)
+To turn all exported functions of a package into commands, use
+ +(replic:functions-to-commands :my-package)
+and you can find them into the readline app.
+ +Setting the completion of commands is easy, we use
+(replic.completion:add-completion "my-function" <list-or-lambda>. For example:
(in-package :replic.user)
+
+(defparameter *names* '()
+ "List of names (string) given to `hello`. Will be autocompleted by `goodbye`.")
+
+(defun hello (name)
+ "Takes only one argument. Adds the given name to the global
+ `*names*` variable, used to complete arguments of `goodbye`.
+ "
+ (format t "hello ~a~&" name)
+ (push name *names*))
+
+(defun goodbye (name)
+ "Says goodbye to name, where `name` should be completed from what was given to `hello`."
+ (format t "goodbye ~a~&" name))
+
+(replic.completion:add-completion "goodbye" (lambda () *names*))
+
+(export '(hello goodbye))
+This example can be used with the executable. What it does is read
+your code from a lisp file (~/.replic.lisp or an argument on the
+command line) and it turns the exported functions into commands, for
+which we can specify custom completion.
For more details, see the readme.
+ ++ +
I use this currently in three apps of mine (like +cl-torrents). It’s +simple. It could be more: it could infer the arguments’ type, do fuzzy +completion, maybe integrate a Lisp editor (Lem) or a lispy shell +(shcl), separate the commands in apps, expose hooks, have a set of +built-in shell related utilities, highlight the input line, it could +be web-based,…
+ +For now it’s going smoothly.
+ +I’ll finish by recalling that it’s amazing to be able to ship +self-contained executables to users !
+ +
+
+ Q1 2019 Survey Results and Call for Proposals
+News on Clojurists Together 08 01 2019
+
+ 
+
+
+ Library Unboxing
+MonkeyUser 08 01 2019
+
+
+ State of Clojure 2019 Survey
+Clojure News 07 01 2019
+
+
+It’s time for the annual State of Clojure Community Survey!
+
+
+If you are a user of Clojure or ClojureScript, we are greatly interested in your responses to the following survey:
+
+
+-
+
- + + +
+
+The survey contains four pages:
+
+
+-
+
-
+
General questions applicable to any user of Clojure or ClojureScript
+
+ -
+
Questions specific to JVM Clojure (skip if not applicable)
+
+ -
+
Questions specific to ClojureScript (skip if not applicable)
+
+ -
+
Final comments
+
+
+
+
+ The survey will close January 22nd, after which all of the data will be released with some analysis. We greatly appreciate your input!
+
+
+ Modeling Polymorphism in Django
+Haki Benita 01 01 2019
+Modeling polymorphism in relational databases is a challenging task. In this article, we present several modeling techniques to represent polymorphic objects in a relational database using the Django object-relational mapping (ORM).
+
+
+ Ideas para conseguir unos regalos más ecos
+Andanzas de una ambientóloga . . . 31 12 2018
+
+
+ Save and Restore Window Configuration in Emacs
+(ノ°Д°）ノ︵ ┻━┻ 25 12 2018
+
+
+ Save and Restore Window Configuration in Emacs
+(ノ°Д°）ノ︵ ┻━┻ 25 12 2018
+
+When we are using emacs sometimes we often open many buffers in different windows at the same time, for example we can have a buffer for a opened file, another for seeing test results and so on.
+There are some tools to manage "sessions" but I wanted something simple and I also wanted to learn a little bit more of elisp so here is the result.
+
+
+(defvar window-snapshots '())
+
+(defun save-window-snapshot ()
+ "Save the current window configuration into `window-snapshots` alist."
+ (interactive)
+ (let ((key (read-string "Enter a name for the snapshot: ")))
+ (setf (alist-get key window-snapshots) (current-window-configuration))
+ (message "%s window snapshot saved!" key)))
+
+(defun get-window-snapshot (key)
+ "Given a KEY return the saved value in `window-snapshots` alist."
+ (let ((value (assoc key window-snapshots)))
+ (cdr value)))
+
+(defun restore-window-snapshot ()
+ "Restore a window snapshot from the window-snapshots alist."
+ (interactive)
+ (let* ((snapshot-name (completing-read "Choose snapshot: " (mapcar #'car window-snapshots)))
+ (snapshot (get-window-snapshot snapshot-name)))
+ (if snapshot
+ (set-window-configuration snapshot)
+ (message "Snapshot %s not found" snapshot-name))))+The code basically do 3 things:
+-
+
-
+
Define an
+alistwhere window configurations will be saved
+ -
+
Save the current window configuration using a name to be identified later.
+
+ -
+
Restore any of the saved configurations by selecting it from a list
+
+
Now let's get into the details:
+
+
++Save the current window configuration +
+
+
+
+We will use the function current-window-configuration to get the current state of the windows and put this value in an alist called window-snapshots. Also it should asks for a name so we can search for it later.
+
+
+(defvar window-snapshots '())
+
+(defun save-window-snapshot ()
+ "Save the current window configuration into `window-snapshots` alist."
+ (interactive)
+ (let ((key (read-string "Enter a name for the snapshot: ")))
+ (setf (alist-get key window-snapshots) (current-window-configuration))
+ (message "%s window snapshot saved!" key)))
+
+
+
+ +Restore a window configuration +
+
+
+
+We will use completing-read to select one of the saved snapshots from an interactive list. It will use helm 1 or ivy 2 if any of those are installed otherwise it will show the options in the minibuffer.
+This will show the name used before and retrieve the value of the window configuration. Then it will apply the configuration using set-window-configuration.
+
+
+(defun get-window-snapshot (key)
+ "Given a KEY return the saved value in `window-snapshots` alist."
+ (let ((value (assoc key window-snapshots)))
+ (cdr value)))
+
+(defun restore-window-snapshot ()
+ "Restore a window snapshot from the window-snapshots alist."
+ (interactive)
+ (let* ((snapshot-name (completing-read "Choose snapshot: " (mapcar #'car window-snapshots)))
+ (snapshot (get-window-snapshot snapshot-name)))
+ (if snapshot
+ (set-window-configuration snapshot)
+ (message "Snapshot %s not found" snapshot-name))))
+ 
+
+
+ Como forzar el volumen del sistema en Ubuntu cuando se oye muy bajo.
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 24 12 2018
+Si nuestro volumen del sistema es muy bajo incluso aunque pongamos los altavoces al 100% existe la posibilidad de forzar al sistema a aumentar el volumen por encima del máximo. Para ello primero tenemos que instalar el programa que se comunica con el hardware de nuestro equipo.
+[code]sudo apt install pulseaudio-utils[/code]+
Después de instalar el programa debemos reiniciar el sistema para que los cambios surjan efecto. Para forzar el volumen del sistema por encima del 100% usaremos el siguiente comando:
+[code]pactl set-sink-volume 0 175%[/code]+
Con esto el volumen de nuestro sistema estará configurado al 175% (por encima de este valor se distorsiona mucho el sonido). El "0" es el indice de la tarjeta de sonido sobre la que estamos aplicando los cambios, para ver las tarjetas de sonido disponibles para nuestro sistema solo tenemos que introducir el siguiente comando:
+[code]pacmd list-sinks | grep -e 'name:' -e 'index'[/code]+
+ 
+
+
+ Como activar/desactivar el arranque UEFI en el PRO 2
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 24 12 2018
+Una vez dentro de la BIOS (Si no sabes como entrar a la BIOS puedes ver este tutorial):
+Para activar/desactivar el arranque UEFI iremos hacia la pestaña "Boot" usando las flechas, dentro de Boot seleccionaremos "UEFI Setting".
+
Una vez dentro podemos activar/desactivar el UEFI Boot.
+
Luego nos iremos a la pestaña "Save & Exit" y pulsaremos en "Save Changes and Exit" o pulsaremos directamente la tecla"F10" para guardar y salir.
+
+ 
+
+
+ Como activar/desactivar el arranque UEFI en el Curve
+Soporte - SLIMBOOK: ultrabooks, portátiles y ordenadores GNU/Linux 24 12 2018
+Una vez dentro de la BIOS (Si no sabes como entrar a la BIOS puedes ver este tutorial):
+Para activar/desactivar el arranque UEFI iremos hacia la pestaña "Chipset" usando las flechas, dentro de Chipset seleccionaremos "CSM Configuration".
+
Una vez dentro podemos cambiar el Boot option filter.
+
Luego nos iremos a la pestaña "Save & Exit" y pulsaremos en "Save Changes and Exit" o pulsaremos directamente la tecla"F10" para guardar y salir.
+
+
+ Projects
+(ノ°Д°）ノ︵ ┻━┻ 24 12 2018
+
+
+ Mujer Científica.
+Andanzas de una ambientóloga . . . 23 12 2018
+
+
+ How We Solved a Storage Problem in PostgreSQL Without Adding a Single Byte of Storage
+Haki Benita 21 12 2018
+A while back we started getting alerts in the middle of the night on low disk space. A quick investigation led us to one of our ETL tasks. Every night the task was fired to eliminate duplicate dumps, and free up some space. This is a short story about how we found our silver bullet and solved the issue without adding a single byte of storage.
+
+
+ Escape The Office (The Game)
+MonkeyUser 21 12 2018
+Escape the office. Merry X-Mas everybody
+
+
+
+
+
+
+
+
+ 
+
+
+ Debugging in Common Lisp
+Lisp journey 20 12 2018
+You entered this new world of Lisp and now wonder: how can we debug +what’s going on ? How is it more interactive than in other platforms +? What does bring the interactive debugger appart from stacktraces ?
+ +note: this tutorial is available on the Common Lisp Cookbook and it will receive updates there.
+ +If you want step-by-step examples of interactive debugging with nice +screenshots and gifs, see the blog posts in the References section +below.
+ + + +Table of Contents
+ +-
+
- Print debugging +
- Logging +
- Using the powerful REPL +
- Inspect and describe +
- The interactive debugger +
- Trace + + +
- Step +
- Break + + +
- Advise and watch +
- Unit tests +
- References +
Print debugging
+ +Well of course we can use the famous technique of “print +debugging”. Let’s just recap a few print functions.
+ +print works, it prints a READable representation of its argument,
+which means what is printed can be read back in by the Lisp
+reader.
princ focuses on an aesthetic representation.
format t "~a" …), with the aesthetic directive, prints a string (in t, the standard output
+stream) and returns nil, whereas format nil … doesn’t print anything
+and returns a string. With many format controls we can print several
+variables at once.
Logging
+ +Logging is a good evolution from print debugging ;)
+ +log4cl is the popular, +de-facto logging library but it isn’t the only one. Download it:
+ +(ql:quickload :log4cl)
+and let’s have a dummy variable:
+ +(defvar *foo* '(:a :b :c))
+We can use log4cl with its log nickname, then it is as simple to use as:
(log:info *foo*)
+;; <INFO> [13:36:49] cl-user () - *FOO*: (:A :B :C)
+We can interleave strings and expressions, with or without format
+control strings:
(log:info "foo is " *foo*)
+;; <INFO> [13:37:22] cl-user () - foo is *FOO*: (:A :B :C)
+(log:info "foo is ~{~a~}" *foo*)
+;; <INFO> [13:39:05] cl-user () - foo is ABC
+With its companion library log4slime, we can interactively change
+the log level:
-
+
- globally, +
- per package, +
- per function, +
- and by CLOS methods and CLOS hierarchy (before and after methods). +
It is very handy, when we have a lot of output, to turn off the +logging of functions or packages we know to work, and thus narrowing +our search to the right area. We can even save this configuration and +re-use it in another image, be it on another machine.
+ +We can do all this through commands, keyboard shortcuts and also through a +menu or mouse clicks.
+ +
We invite you to read log4cl’s readme.
+ +Using the powerful REPL
+ +Part of the joy of Lisp is the excellent REPL. Its existence usually +delays the need to use other debugging tools, if it doesn’t annihilate +them for the usual routine.
+ +As soon as we define a function, we can try it in the REPL. In Slime,
+compile a function with C-c C-c (the whole buffer with C-c C-k),
+switch to the REPL with C-c C-z and try it. Eventually enter the
+package you are working on with (in-package :your-package).
The feedback is immediate. There is no need to recompile everything, +nor to restart any process, nor to create a main function and define +command line arguments for use in the shell (we can do this later on +when needed).
+ +We usually need to create some data to test our function(s). This is a
+subsequent art of the REPL existence and it may be a new discipline
+for newcomers. A trick is to write the test data alongside your
+functions but inside a #+nil declaration so that only you can
+manually compile them:
#+nil
+ (progn
+ (defvar *test-data* nil)
+ (setf *test-data* (make-instance 'foo …)))
+When you load this file, *test-data* won’t exist, but you can
+manually create it with a C-c C-c away.
We can define tests functions like this.
+ +Some do similarly inside #| … |# comments.
All that being said, keep in mind to write unit tests when time comes ;)
+ +Inspect and describe
+ +These two commands share the same goal, printing a description of an
+object, inspect being the interactive one.
(inspect *foo*)
+
+The object is a proper list of length 3.
+0. 0: :A
+1. 1: :B
+
+2. 2: :C
+> q
+We can also, in editors that support it, right-click on any object in
+the REPL and inspect them. We are presented a screen where we can
+dive deep inside the data structure and even change it.
Let’s have a quick look with a more interesting structure, an object:
+ +(defclass foo ()
+ ((a :accessor foo-a :initform '(:a :b :c))
+ (b :accessor foo-b :initform :b)))
+;; #<STANDARD-CLASS FOO>
+(make-instance 'foo)
+;; #<FOO {100F2B6183}>
+We right-click on the #<FOO object and choose “inspect”. We are
+presented an interactive pane (in Slime):
#<FOO {100F2B6183}>
+--------------------
+Class: #<STANDARD-CLASS FOO>
+--------------------
+ Group slots by inheritance [ ]
+ Sort slots alphabetically [X]
+
+All Slots:
+[ ] A = (:A :B :C)
+[ ] B = :B
+
+[set value] [make unbound]
+When we click or press enter on the line of slot A, we inspect it further:
+ +#<CONS {100F5E2A07}>
+--------------------
+A proper list:
+0: :A
+1: :B
+2: :C
+The interactive debugger
+ +Whenever an exceptional situation happens (see +error handling), the interactive debugger pops +up.
+ +It presents the error message, available actions (restarts), +and the backtrace. A few remarks:
+ +-
+
- the restarts are programmable, we can create our owns, +
- in Slime, press
von a stacktrace to be redirected to the source +file at the right line,
+ - hit enter on a frame for more details, +
- we can explore the functionnality with the menu that should appear +in our editor. See below in “break” section for a few +more commands (eval in frame, etc). +
Usually your compiler will optimize things out and this will reduce
+the amount of information available to the debugger. For example
+sometimes we can’t see intermediate variables of computations. You might
+want to print a function argument (with e to “eval in frame”, see
+below), but you keep getting a Variable XYZ is unbound error.
To fix this, we have to change the optimization choices with declaim, at the beginning of the file:
(declaim (optimize (speed 0) (space 0) (debug 3)))
+or with declare, inside a defun:
(defun my-fun (xyz)
+ (declare (optimize (debug 3)))
+ …)
+and recompile the code. Now you should be able to see local variables such asxyz.
Trace
+ +trace allows us to see when a +function was called, what arguments it received, and the value it +returned.
+ +(defun factorial (n)
+ (if (plusp n)
+ (* n (factorial (1- n)))
+ 1))
+(trace factorial)
+
+(factorial 2)
+ 0: (FACTORIAL 3)
+ 1: (FACTORIAL 2)
+ 2: (FACTORIAL 1)
+ 3: (FACTORIAL 0)
+ 3: FACTORIAL returned 1
+ 2: FACTORIAL returned 1
+ 1: FACTORIAL returned 2
+ 0: FACTORIAL returned 6
+6
+
+(untrace factorial)
+To untrace all functions, just evaluate (untrace).
In Slime we also have the shortcut C-c M-t to trace or untrace a
+function.
If you don’t see recursive calls, that may be because of the +compiler’s optimizations. Try this before defining the function to be +traced:
+ +(declaim (optimize (debug 3)))
+The output is printed to *trace-output* (see the CLHS).
In Slime, we also have an interactive trace dialog with M-x
+slime-trace-dialog bound to C-c T.
Tracing method invocation
+ +In SBCL, we can use (trace foo :methods t) to trace the execution order of method combination (before, after, around methods). For example:
(trace foo :methods t)
+
+(foo 2.0d0)
+ 0: (FOO 2.0d0)
+ 1: ((SB-PCL::COMBINED-METHOD FOO) 2.0d0)
+ 2: ((METHOD FOO (FLOAT)) 2.0d0)
+ 3: ((METHOD FOO (T)) 2.0d0)
+ 3: (METHOD FOO (T)) returned 3
+ 2: (METHOD FOO (FLOAT)) returned 9
+ 2: ((METHOD FOO :AFTER (DOUBLE-FLOAT)) 2.0d0)
+ 2: (METHOD FOO :AFTER (DOUBLE-FLOAT)) returned DOUBLE
+ 1: (SB-PCL::COMBINED-METHOD FOO) returned 9
+ 0: FOO returned 9
+9
+See the CLOS section for a tad more information.
+ +Step
+ +step is an interactive command with
+similar scope than trace. This:
(step (factorial 2))
+gives an interactive pane with the available restarts:
+ +Evaluating call:
+ (FACTORIAL 2)
+With arguments:
+ 2
+ [Condition of type SB-EXT:STEP-FORM-CONDITION]
+
+Restarts:
+ 0: [STEP-CONTINUE] Resume normal execution
+ 1: [STEP-OUT] Resume stepping after returning from this function
+ 2: [STEP-NEXT] Step over call
+ 3: [STEP-INTO] Step into call
+ 4: [RETRY] Retry SLIME REPL evaluation request.
+ 5: [*ABORT] Return to SLIME's top level.
+ --more--
+
+Backtrace:
+ 0: ((LAMBDA ()))
+ 1: (SB-INT:SIMPLE-EVAL-IN-LEXENV (LET ((SB-IMPL::*STEP-OUT* :MAYBE)) (UNWIND-PROTECT (SB-IMPL::WITH-STEPPING-ENABLED #))) #S(SB-KERNEL:LEXENV :FUNS NIL :VARS NIL :BLOCKS NIL :TAGS NIL :TYPE-RESTRICTIONS ..
+ 2: (SB-INT:SIMPLE-EVAL-IN-LEXENV (STEP (FACTORIAL 2)) #<NULL-LEXENV>)
+ 3: (EVAL (STEP (FACTORIAL 2)))
+Stepping is useful, however it may be a sign that you need to simplify your function.
+ +Break
+ +A call to break makes the program +enter the debugger, from which we can inspect the call stack.
+ +Breakpoints in Slime
+ +Look at the SLDB menu, it shows navigation keys and available
+actions. Of which:
-
+
e(sldb-eval-in-frame) prompts for an expression and evaluates +it in the selected frame. This is how we can explore our +intermediate variables.
+dis similar with the addition of pretty printing the result.
+
Once we are in a frame and detect a suspicious behavior, we can even +re-compile a function at runtime and resume the program execution from +where it stopped (using the “step-continue” restart).
+ +Advise and watch
+ +advise and
+watch are available in some vendor
+implementations, like LispWorks. They are not available in
+SBCL. advise allows to modify a function without changing its
+source, or to do something before or after its execution, like CLOS’
+method combination (befor, after around methods).
watch allows to specify variables to be displayed in some GUI during
+the program execution.
Unit tests
+ +Last but not least, automatic testing of functions in isolation might +be what you’re looking for ! See the testing section and a list of +test frameworks and libraries.
+ +References
+ +-
+
- “How to understand and use Common Lisp”, chap. 30, David Lamkins (book download from author’s site) +
- Malisper: debugging Lisp series +
- Two Wrongs: debugging Common Lisp in Slime +
+
+ Clojure 1.10 release
+Clojure News 17 12 2018
+
+
+
+
+
+
+Clojure 1.10 focuses on two major areas: improved error reporting and Java compatibility.
+
+
+Error reporting at the REPL now categorizes errors based on their phase of execution (read, macroexpand, compile, etc). Errors carry additional information about location and context as data, and present phase-specific error messages with better location reporting. This functionality is built into the clojure.main REPL, but the functionality is also available to other REPLs and tools with the ability to use and/or modify the data to produce better error messages.
+
+
+Clojure 1.10 now requires Java 8 or above and has been updated particularly for compatibility with Java 8 and Java 11. Changes included bytecode-related bug fixes, removed use of deprecated APIs, and updates related to the module system introduced in Java 9.
+
+
+See the change log for a complete list of all fixes, enhancements, and new features in Clojure 1.10.
+
+
+
+ Contributors
+
+
+
+
+Thanks to all of the community members who contributed patches to Clojure 1.10 (first time contributors in bold):
+
+
+-
+
-
+
Alexander Kiel
+
+ -
+
Ben Bader
+
+ -
+
Bruce Adams
+
+ -
+
Cezary Kosko
+
+ -
+
Erik Assum
+
+ -
+
Eugene Kostenko
+
+ -
+
Ghadi Shayban
+
+ -
+
Gijs Stuurman
+
+ -
+
Jozef Wagner
+
+ -
+
Kwang Yul Seo
+
+ -
+
Matthew Gilliard
+
+ -
+
Michał Marczyk
+
+ -
+
Nicola Mometto
+
+ -
+
Nikita Prokopov
+
+ -
+
Sean Corfield
+
+ -
+
Sebastien Martel
+
+ -
+
Shogo Ohta
+
+ -
+
Stuart Sierra
+
+
+
+ November 2018 Monthly Update
+News on Clojurists Together 12 12 2018
+
+ 
+
+
+ Replace All
+MonkeyUser 12 12 2018
+
+
+ VSCode + TypeScript + Prettier = Happy Developer
+Blogs on Tom Spencer 07 12 2018
+
+
+ VSCode + TypeScript + Prettier = Happy Developer
+Blogs on Tom Spencer 07 12 2018
+
+ 
+
+
+ Instapaper iOS 7.7: iPad Pro, Smart Keyboard, and True Black
+Instapaper 06 12 2018
+Instapaper 7.7 is now live in the iOS App Store with support for iPad Pro, Smart Keyboard shortcuts, and a True Black theme for iPhone X devices.
For Smart Keyboards, Instapaper now supports the following shortcuts:
- ▲ and ▼ to navigate through articles in list view, ◀ and ▶ to navigate through articles in grid view
- ↩ to open article from list
- ⌘+A to archive an article
- ⌘+M to move an article
- ⌘+D to delete an article
- ⌘+◀ to navigate back
- ⌘+F to perform a local, title-based search
- ⌘+⇧+ F to trigger full-text search for Premium users
- Esc to leave search
- Space and ⇧+space to page up and down in list or from inside article
In case you forget, holding ⌘ will bring up the list of shortcuts available on the current screen.
It took a considerable amount of work to get basic navigational support for Smart Keyboards, so we created an open source library called IPShortcut that provides Smart Keyboard shortcuts for table views, collection views, and scroll views.
The new True Black theme takes advantage of the OLED screens for iPhone X, iPhone XS, and iPhone XS Max to offer an even better experience when reading in dark mode. Screens on these devices display black by turning those pixels off on the screen, which is particularly great for reading at night. To get started, just switch to the dark mode theme on one of these devices.
If you have any questions, feature requests, or issues you’d like us to sort out, please let us know at support@instapaper.com or @InstapaperHelp on Twitter. We love hearing from you and we thank you for using Instapaper!
- Instapaper Team
+
+
+ One liner, Git from Lisp: commit every file of this repository
+Lisp journey 04 12 2018
+Hey, pardon this very short post, it’s just for the pleasure of +blogging, and to balance the usual lengthy ones.
+ +I wanted to commit, one by one, every file of the current directory +(it’s useless, don’t ask).
+ +I use legit as the interface to +Git, and this one-liner:
+ +(dolist (file (uiop:directory-files "./"))
+ (legit:git-add :paths (pathname file))
+ (legit:git-commit :files (pathname file) :message (format nil "add ~a" (file-namestring file))))
+I guessed the :paths and :files arguments with Slime’s command
+argument list which appears in the modline, I wanted a function to
+convert a /full/path/file.cl to a name file.cl and tried the
+completion for file-… and found the right thing without effort. I
+saw on the complete documentation that legit:commit wanted a
+repository object as first argument, which makes sense, but
+legit:git-commit doesn’t and I just iterate on the current working
+directory (btw change it in Slime with the ,cd command) so it was
+shorter for me.
Just a one liner.
+ +++ +Oh my god, I didn’t know we can do this in Lisp !
+
Of course we can :p
+ +
+ 
+
+
+ Trial And
+MonkeyUser 04 12 2018
+
+ 
+
+
+ La libertad de desarrollar...: Visualizando estadisticas de pokemon usando plotly ( gráfica de radar)
+Python Hispano 02 12 2018
+
Luego de un tiempo sin escribir, retomo los artículos sobre Ciencia de Datos, ahora con visualización de datos. Para ello se usará la estadística de un repositorio de datos sobre los pokemon.
El gráfico radar es un gráfico que consiste en una secuencia de radios equi-angulares, llamados radios, y cada radio representa una de las variables. La longitud de los datos de un radio es proporcional a la magnitud de la variable para el punto de datos en relación con la longitud máxima de la variable en todos los puntos de datos. Se dibuja una línea que conecta con los valores de los datos para cada radio. Esto le da a la trama una apariencia de estrella (wikipedia). Pueden ver un ejemplo en la siguiente figura:
La idea es mostrar multiples variables sobre la información que se tiene de los pokemons. El repositorio de datos de donde se obtiene los datos para trabajar es el sitio de kaggle.
La librería de Python que se usará en este artículo para visualizar los datos usando la gráfica radar se llama plotly, en el siguiente enlace podrán ver una galería de gráficas usando python, ya que dicha librería se puede usar también en el Lenguaje R y en Javascript. Lo bueno de plotly es que maneja más interactividad o dinamismo a las gráficas, no son simples gráficas estáticas. Plotly se puede usar en línea o desconectado.
La idea de hacer este artículo sobre visualizando estadísticas de pokemon usando plotly fue de un artículo donde usan la gráfica radar pero con matplotlib.
El tutoral básico de como usar la gráfica radar en plotly lo pueden ver en el siguiente enlace.
Este artículo se basa en un notebook que se encuentra en kaggle.
La información que contiene el repositorio es la siguiente:
- #: ID de cada pokemon.
- Name: Nombre de cada pokemon.
- Type 1: Cada pokemon tiene un tipo, esto determina su debilidad/resistencia a ataques.
- Type 2: Algunos pokemon tienen dos tipos.
- Total: Suma de todas las estadísticas.
- HP: Hit point, o health.
- Defense: Nivel de resistencia a los ataques.
- SP Atk: ataque especial.
- SP Def: Resistencia contra ataques especiales.
- Speed: Velocidad en el ataque.
Visualización de estadística de pokemon usando gráfica de radar¶
Enlaces de interés¶
https://typewind.github.io/2017/09/29/radar-chart/https://www.kaggle.com/abcsds/pokemon/data
https://plot.ly/python/radar-chart/
https://www.kaggle.com/thebrownviking20/intermediate-visualization-tutorial-using-plotly
Se importa las librerías necesarias¶
In [1]:
import pandas as pd
import numpy as np
import plotly.plotly as py
import plotly.graph_objs as go
import plotly
import matplotlib.pyplot as plt
from plotly import tools
from plotly.offline import init_notebook_mode, iplot
init_notebook_mode(connected=True)
import plotly.figure_factory as ff
from IPython.display import HTML, Image
Se lee y convierte el archivo csv de los datos de pokemon en un dataframe¶
In [2]:
df=pd.read_csv("./datos/Pokemon.csv")
Se muestra las 5 primeras filas de datos¶
In [3]:
df.head()
Out[3]:
Se muestra el tipo de dato de cada columna que maneja el dataframe.¶
In [4]:
df.info()
Se visualiza los datos de un sólo pokemon¶
In [5]:
#Se busca los datos del pokemon Charizard
x = df[df["Name"] == "Charizard"]
#Se crea la grafica scatterpolar donde se le pasa las variables que se quiere graficar. HP, Ataque, defensa, SP atk,
#Sp def, velocidad y se define los nombres de los ejes.
data = [go.Scatterpolar(
r = [x['HP'].values[0],x['Attack'].values[0],x['Defense'].values[0],x['Sp. Atk'].values[0],x['Sp. Def'].values[0],x['Speed'].values[0],x["HP"].values[0]],
theta = ['HP','Attack','Defense','Sp. Atk','Sp. Def','Speed','HP'],
fill = 'toself'
)]
# se crea el layout, donde se le pasa un diccionario donde se define los ejes de los radios, que son visibles y
#su rango en este caso desde 0 a 250, no se muestra legenda, y el título de la gráfica.
layout = go.Layout(
polar = dict(
radialaxis = dict(
visible = True,
range = [0, 250]
)
),
showlegend = False,
title = "Stats of {}".format(x.Name.values[0])
)
#Se crea la instancia fig donde se pasa los datos y el layout.
fig = go.Figure(data=data, layout=layout)
#Se gràfica la gráfica
iplot(fig, filename = "Single Pokemon stats")
Comparación de 2 pokemons¶
In [6]:
# Se crea una función donde se hace la comparación vía gráfica de la estadística de dos pokemons.
def compare2pokemon(x,y):
#Se captura los datos de los dos pokemons
x = df[df["Name"] == x]
y = df[df["Name"] == y]
#Se define lo que se quiere gráficar del primer y segundo pokemon.
trace0 = go.Scatterpolar(
r = [x['HP'].values[0],x['Attack'].values[0],x['Defense'].values[0],x['Sp. Atk'].values[0],x['Sp. Def'].values[0],x['Speed'].values[0],x["HP"].values[0]],
theta = ['HP','Attack','Defense','Sp. Atk','Sp. Def','Speed','HP'],
fill = 'toself',
name = x.Name.values[0]
)
trace1 = go.Scatterpolar(
r = [y['HP'].values[0],y['Attack'].values[0],y['Defense'].values[0],y['Sp. Atk'].values[0],y['Sp. Def'].values[0],y['Speed'].values[0],y["HP"].values[0]],
theta = ['HP','Attack','Defense','Sp. Atk','Sp. Def','Speed','HP'],
fill = 'toself',
name = y.Name.values[0]
)
#se define data como una lista que contiene los datos de los dos pokemon
data = [trace0, trace1]
#Se define el layout como en la gráfica anterior.
layout = go.Layout(
polar = dict(
radialaxis = dict(
visible = True,
range = [0, 200]
)
),
showlegend = True,
title = "{} vs {}".format(x.Name.values[0],y.Name.values[0])
)
#Se crea la instancia donde se pasa los datos y el layout
fig = go.Figure(data=data, layout=layout)
#Se crea la grafica.
iplot(fig, filename = "Two Pokemon stats")
In [7]:
# Se compara primeape y muk
compare2pokemon("Primeape", "Muk")
En siguientes artículos se seguirá mostrando ejemplos de usos de la galería de gráficas de plotly.
+
+ 2018 Committee Election Results
+News on Clojurists Together 30 11 2018
+
+
+
+
+ The Trackers Who Steal
+WhoTracksMe blog 22 11 2018
+
+
+ Object destructuring and currying in functional JavaScript
+James Sinclair 20 11 2018
+
+
+ Object destructuring and currying in functional JavaScript
+Web Development - James Sinclair 20 11 2018
+
+
+ 2018 Committee Election Candidates
+News on Clojurists Together 15 11 2018
+
+ 
+
+
+ Opinions
+MonkeyUser 14 11 2018
+
+ 
+
+
+ Overview of Documentation Generators
+Lisp journey 07 11 2018
+I have a simple need: I’d like to generate an html documentation from +my code. What options do we have ?
+ +I searched for “documentation tool” on Quickdocs: +http://quickdocs.org/search?q=documentation%20tool, from which I +remove old ones (clod, qbook, manifest).
+ +I had two pure Lisp solutions working out of the box, two more are of +interest, and there’s another non-Lisp of interest.
+ +update: just found out that qbook +(github mirror)is used for the +documentation of Fiveam, which is pretty nice: +https://common-lisp.net/project/fiveam/docs/index.html It can produce +html and latex. It uses docstrings and comments that start with 4 +commas to structure the page +(exple in source +that gives +this). Running +it has a lot of asdf deprecation warnings and it did not work out of +the box for me (“The slot IT.BESE.QBOOK::GENERATOR is unbound in the object”).
+ +Codex
+ +Codex produces nice html but isn’t automatic.
+ +-
+
- https://github.com/CommonDoc/codex (by @eudoxia) +
- example: https://commondoc.github.io/codex/docs/tutorial.html +
- input fromat: scriba by default. No more format it seems. +
- output: multiple html files. +
- rendering: modern, colored, light, TOC on the side +
- granularity: good +
- link to CLHS: yes +
- totally automatic: no (one needs to create the documentation structure in
manual.lisp, AFAIU).
+ - used in the wild: yes +
Getting started: write a simple docs/manifest.lisp and docs/manual.lisp.
Am I mistaking ? It’s exclusively manual. We must supply every
+function/generic function/method/class/macro to document in
+manual.lisp.
Coo
+ +Coo is a new tool in town, it works out of the box and it is actively developed !
+ +-
+
- https://github.com/fisxoj/coo +
- https://fisxoj.github.io/coo/ +
- input: docstrings in
rst
+ - output: multiple html +
- rendering: black & white, no TOC (active development) +
- links to CLHS: yes, since yesterday :) +
- granularity: doesn’t show class slots, doesn’t show generic functions. +
- used in the wild: coo no, more probably cl-docutils. +
Based on cl-docutils.
+ +Displays the functions’ documentation following their order in source (or not ? I saw exceptions).
+ +It’s straightforward:
+ +(coo:document-system :my-system)
+and it produces html into docs/.
Staple (doesn’t work on Debian’s SBCL 1.2.4)
+ +You may be familiar with Staple since it’s used by Shinmera in all his projects.
+ +-
+
- https://github.com/Shinmera/staple +
- output: html. The documentation string is plain text (no markup, rendered in a
<pre>tag).
+ - cross-references +
- can use a template. +
- more features than listed here. +
It doesn’t support SBCL 1.2.4, so my tests fell short (upgrading isn’t +100% smooth here). If you’re on SBCL >= 1.4.8 Staple is a good option.
+ +Declt
+ +Declt has higher goals than “quick and easy” documentation generator.
+ +-
+
- https://github.com/didierverna/declt +
- https://www.lrde.epita.fr/~didier/software/lisp/declt/ +
- output: a
.texifile, that we can render into other formats (html, pdf).
+ - cross-references: yes +
It didn’t work out of the box (and had no explicit error information) +and it’s also too involved for my use case.
+ +Documentation-tool (not for general use)
+ +It’s the template used for Edi Weitz software, like Hunchentoot.
+ +-
+
- https://edicl.github.io/documentation-template/ +
- output: one html file +
It works, but it thinks you publish an edicl software and has some hardcoded “http://weitz.de/files/…" urls.
+ +Tinaa (unmaintained)
+ +I liked the output, but it didn’t work (asdf-related error), and it’s unmaintained (authors’ words).
+ +-
+
- https://github.com/gwkkwg/tinaa +
- https://common-lisp.net/project/tinaa/documentation/index.html +
- output: html +
See also
+ +cl-domain (Sphinx)
+ +Another excellent option is 40ants’ cldomain, which builds on Python’s proven Sphinx:
+ +++ +CLDomain is an extension for the Sphinx documentation generation tool that allow sphinx to generate documentation for Common Lisp libraries. Documentation is extracted from the various entity’s documentation strings, loaded from ASDF systems and associated internal packages.
+
They use it for they new projects since around 3 years now.
+ +-
+
- https://github.com/40ants/cldomain +
- http://40ants.com/cldomain/ +
- input: rst +
- output: many html +
- HyperSpec links: yes +
- requirements: Python, pip +
udate 2019-01-22: extended example.
+ +An example from cl-hamcrest:
+ +-
+
- we reference Lisp functions/methods/macros with RST directives: +
Object matchers
+===============
+
+This kind of matchers checks some sort of properties on an object, etc.
+
+.. cl:package:: hamcrest/matchers
+
+.. cl:macro:: has-plist-entries
+-
+
- they have RST docstrings, also with RST directives to include code blocks: +
(def-has-macro
+ has-plist-entries
+ "Matches plist entries:
+
+.. code-block:: common-lisp-repl
+
+ TEST> (let ((obj '(:foo :bar)))
+ (assert-that obj
+ (has-plist-entries :foo \"bar\"
+ :blah \"minor\")))
+ × Key :FOO has :BAR value, but \"bar\" was expected
+
+This way you can test any number of plist's entries."
+
+ :check-obj-type (check-if-list object)
+ :get-key-value (let ((key-value (getf object key 'absent)))
+ (when (eql key-value 'absent)
+ …
+-
+
- this produces a nice output (here): +
+ +
I’ll use and watch Coo !
+ +
+
+ Join the Clojurists Together Committee
+News on Clojurists Together 06 11 2018
+
+ 
+
+
+ Last Push
+MonkeyUser 06 11 2018
+
+
+ Optimizing the Django Admin Paginator
+Haki Benita 05 11 2018
+I often talk about making Django scale but what does it actually mean? It means getting consistent performance regardless of the amount of data. In this article we tackle The last nail in Django admin's scalability coffin - the paginator.
+
+
+ October 2018 Monthly Update
+News on Clojurists Together 04 11 2018
+
+ 
+
+
+ Reminiscing
+MonkeyUser 30 10 2018
+
+
+ We now have comments. Thanks, Utterances !
+Lisp journey 25 10 2018
+We just installed a comment system, and it isn’t Disqus ! We just +discovered https://utteranc.es/, a lightweight widget +based on Github issues. If it doesn’t find an issue corresponding to +the current article, it will create one and post your comment +there. Simple :) You dreamed of it ? They did it.
+ +
+ 
+
+
+ Test Optimization
+MonkeyUser 24 10 2018
+
+
+ Sylvia A. Earle Premio Princesa de Asturias de la Concordia
+Andanzas de una ambientóloga . . . 20 10 2018
+
+ 
+
+
+ Priorities
+MonkeyUser 17 10 2018
+
+ 
+
+
+ La libertad de desarrollar...: Analizando datos del cambio climático y niveles de CO2 en la atmosfera con Python y pandas.
+Python Hispano 14 10 2018
+Continuando con los artículos sobre ciencia de datos, esta vez se analizará datos sobre información del clima global y por países, así como los niveles de CO2.
Estos datos y proyecto los encontré en el sitio kaggle, este sitio es para publicar proyectos de ciencia de datos. Los datos para este artículo lo encuentran en el siguiente enlace.
El código de este artículo se basa en el artículo que se encuentra en kaggle sobre el tema en inglés Climate Change and CO2 levels in atmosphere.
En este artículo se explora los cambios globales de la temperatura media y el incremento de la concentración del CO2 en la atmosfera.
Los datos se obtienen de los siguientes archivos:
- GlobalLandTemperaturesByCountry.csv: Contiene la información de la temperatura por país.
- GlobalTemperatures.csv: Contiene la información global de la temperatura.
- archive.csv: Contiene la información de los niveles de CO2 en la atmosfera.
A continuación se muestra el notebook:
Se importa las librerías de pantas, matplotlib y seaborn.¶
In [1]:
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
Se crea los dataframes a partir de los archivos csv.¶
In [2]:
# Se crea el dataframe data_pais, data_vzla, data_global y co2_ppm
data_pais = pd.read_csv("./datos/GlobalLandTemperaturesByCountry.csv")
#Se crea una copia del dataframe obteniendo solo la información de Venezuela.
data_vzla = data_pais[data_pais["Country"] == "Venezuela"].copy()
data_vzla["dt"] = pd.to_datetime(data_vzla["dt"])
#Se crea una copia del dataframe obteniendo solo la información de Argentina.
data_arg = data_pais[data_pais["Country"] == "Argentina"].copy()
data_arg["dt"] = pd.to_datetime(data_arg["dt"])
#Se crea una copia del dataframe obteniendo solo la información de USA.
data_canada = data_pais[data_pais["Country"] == "Canada"].copy()
data_canada["dt"] = pd.to_datetime(data_canada["dt"])
#Se crea una copia del dataframe obteniendo solo la información de Mexico.
data_mexico = data_pais[data_pais["Country"] == "Mexico"].copy()
data_mexico["dt"] = pd.to_datetime(data_mexico["dt"])
#Se crea una copia del dataframe obteniendo solo la información de Brasil.
data_brasil = data_pais[data_pais["Country"] == "Brazil"].copy()
data_brasil["dt"] = pd.to_datetime(data_brasil["dt"])
#Se crea una copia del dataframe obteniendo solo la información de Venezuela.
data_chile = data_pais[data_pais["Country"] == "Chile"].copy()
data_chile["dt"] = pd.to_datetime(data_chile["dt"])
#Se crea el dataframe de la temperatura global.
data_global = pd.read_csv("./datos/GlobalTemperatures.csv")
#Se modifica la fecha y hora como datetime.
data_global["dt"] = pd.to_datetime(data_global["dt"])
#Se crea el dataframe del co2.
co2_ppm = pd.read_csv("./datos/archive.csv")
Los dataframes creados.¶
In [3]:
data_pais.head()
Out[3]:
Como se puede observar, se tiene la fecha, la temperatura promedio, la temperatura promedio de incertidumbre y país.
In [4]:
data_pais.info()
Los tipos de datos de las columnas son dt objeto, temperatura promedio y temperatura promedio de incertidumbre son float64 y country como objeto
Venezuela¶
In [5]:
data_vzla.head()
Out[5]:
Se tiene la misma información anterior pero sólo de Venezuela.
In [6]:
data_vzla.describe().T
Out[6]:
Se tiene 2086 datos, los cuales la temperatura promedio es 25.025 grados, y la incertidumbre es de 0.586, la desviación de la temperatura promedio es de 0.703, y de la incertidumbre es de 0.398, la mínima temperatura fue de 22.77, la máxima de 27.807.
In [7]:
data_vzla.corr()
Out[7]:
Las dos variables tienen una correlación contraria en cierta manera.
Argentina¶
In [8]:
data_arg.head()
Out[8]:
In [9]:
data_arg.describe().T
Out[9]:
Brasil¶
In [10]:
data_brasil.head()
Out[10]:
In [11]:
data_brasil.describe().T
Out[11]:
Chile¶
In [12]:
data_chile.head()
Out[12]:
In [13]:
data_chile.describe().T
Out[13]:
Mexico¶
In [14]:
data_mexico.head()
Out[14]:
In [15]:
data_mexico.describe().T
Out[15]:
Canadá¶
In [16]:
data_canada.head()
Out[16]:
In [17]:
data_canada.describe().T
Out[17]:
Se nota que las variaciones de la temperatura promedio de incertidumbre es mayor en Brasil, Venezuela, Mexico y Canadá en ese orden, con respecto a Chile y Argentina.
Incremento anual de la temperatura promedio global¶
In [18]:
annual_mean_global = data_global.groupby(data_global["dt"].dt.year).mean()
reference_temperature_global = annual_mean_global.loc[1951:1980].mean()["LandAndOceanAverageTemperature"]
annual_mean_global["Anomaly"] = annual_mean_global["LandAndOceanAverageTemperature"] - reference_temperature_global
In [19]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_global.loc[1960:2015]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Anomalia anual de la temperatura promedio global")
plt.xlabel('')
plt.ylabel('Anomalia de la temperatura')
plt.show()
Se nota que anualmente el incremento de la temperatura tiene una tendencia ascendente que ha aumentado en los últimos años, este incremento en el año 2015 fue de 0.75 grados que es conscistente con el cambio climático.
Venezuela.¶
Se hace el mismo cálculo para el caso de Venezuela.In [20]:
annual_mean_vzla = data_vzla.groupby(data_vzla["dt"].dt.year).mean()
reference_temperature_vzla = annual_mean_vzla.loc[1951:1980].mean()["AverageTemperature"]
annual_mean_vzla["Anomaly"] = annual_mean_vzla["AverageTemperature"] - reference_temperature_vzla
In [21]:
annual_mean_vzla.head()
Out[21]:
In [22]:
annual_mean_vzla.tail()
Out[22]:
El último registro es del año 2013, el cual el incremento fue de 0.595 grados, hubo un pico en el año 2010 de 0.8332 grados.
In [23]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_vzla.loc[1960:2012]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Variación promedio anual de la temperatura de Venezuela")
plt.xlabel('')
plt.ylabel('Incremento de la temperatura')
plt.show()
Argentina¶
In [24]:
annual_mean_arg = data_arg.groupby(data_arg["dt"].dt.year).mean()
reference_temperature_arg = annual_mean_arg.loc[1951:1980].mean()["AverageTemperature"]
annual_mean_arg["Anomaly"] = annual_mean_arg["AverageTemperature"] - reference_temperature_arg
In [25]:
annual_mean_arg.head()
Out[25]:
In [26]:
annual_mean_arg.tail()
Out[26]:
In [27]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_arg.loc[1960:2012]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Variación promedio anual de la temperatura de Argentina")
plt.xlabel('')
plt.ylabel('Incremento de la temperatura')
plt.show()
Para el caso de Argentina la pendiente de la tendencia de incremento de la temperatura es menos pronunciada.
Brasil¶
In [28]:
annual_mean_brasil = data_brasil.groupby(data_brasil["dt"].dt.year).mean()
reference_temperature_brasil = annual_mean_brasil.loc[1951:1980].mean()["AverageTemperature"]
annual_mean_brasil["Anomaly"] = annual_mean_brasil["AverageTemperature"] - reference_temperature_brasil
In [29]:
annual_mean_brasil.head()
Out[29]:
In [30]:
annual_mean_brasil.tail()
Out[30]:
In [31]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_brasil.loc[1960:2012]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Variación promedio anual de la temperatura de Brasil")
plt.xlabel('')
plt.ylabel('Incremento de la temperatura')
plt.show()
En el caso de Brasil se nota un fuerte incremento en la decada de los 90s con un pico de más de 1 grado, luego la tendencia se ha estabilizado en 0.79 grados.
Chile¶
In [32]:
annual_mean_chile = data_chile.groupby(data_chile["dt"].dt.year).mean()
reference_temperature_chile = annual_mean_chile.loc[1951:1980].mean()["AverageTemperature"]
annual_mean_chile["Anomaly"] = annual_mean_chile["AverageTemperature"] - reference_temperature_chile
In [33]:
annual_mean_chile.head()
Out[33]:
In [34]:
annual_mean_chile.tail()
Out[34]:
In [35]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_chile.loc[1960:2012]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Variación promedio anual de la temperatura de Chile")
plt.xlabel('')
plt.ylabel('Incremento de la temperatura')
plt.show()
La variación no supera el 0.8 grados de temperatura, con un aumento fuerte entre los 70s y 80s y luego un pico en los 90s.
Mexico¶
In [36]:
annual_mean_mexico = data_mexico.groupby(data_mexico["dt"].dt.year).mean()
reference_temperature_mexico = annual_mean_mexico.loc[1951:1980].mean()["AverageTemperature"]
annual_mean_mexico["Anomaly"] = annual_mean_mexico["AverageTemperature"] - reference_temperature_mexico
In [37]:
annual_mean_mexico.head()
Out[37]:
In [38]:
annual_mean_mexico.tail()
Out[38]:
In [39]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_mexico.loc[1960:2012]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Variación promedio anual de la temperatura de Mexico")
plt.xlabel('')
plt.ylabel('Incremento de la temperatura')
plt.show()
Se nota la tendencia al alsa de la temperatura en Mexico pasando el año 2013 a estar por 1.48 grados por encima del promedio.
Canadá¶
In [40]:
annual_mean_canada = data_canada.groupby(data_canada["dt"].dt.year).mean()
reference_temperature_canada = annual_mean_canada.loc[1951:1980].mean()["AverageTemperature"]
annual_mean_canada["Anomaly"] = annual_mean_canada["AverageTemperature"] - reference_temperature_canada
In [41]:
annual_mean_canada.head()
Out[41]:
In [42]:
annual_mean_canada.tail()
Out[42]:
In [43]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_mean_canada.loc[1960:2012]["Anomaly"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Variación promedio anual de la temperatura de Canadá")
plt.xlabel('')
plt.ylabel('Incremento de la temperatura')
plt.show()
Se nota la tendencia al alsa de la temperatura en Canadá y lo preocupante es que la variación pase los 3 grados de temperatura en el año 2013.
Niveles anuales de CO2 en la Atmosfera¶
In [44]:
plt.figure()
plt.style.use("fivethirtyeight")
annual_co2_ppm = co2_ppm.groupby(co2_ppm["Year"]).mean()
annual_co2_ppm.loc[1960:2015]["Carbon Dioxide (ppm)"].plot(figsize = (10,5), grid=True, legend=True)
plt.title("Nivel anual global de CO2 en la Atmosfera")
plt.ylabel("CO2 partes por millón")
plt.show()
Se nota el incremento anual con tendencia al alza.
Se cálcula la relación del CO2 con la temperatura.¶
In [45]:
annual_co2_temp = pd.merge(annual_mean_global.loc[1960:2015], annual_co2_ppm.loc[1960:2015], left_index=True, right_index=True)
annual_co2_temp = annual_co2_temp[["LandAndOceanAverageTemperature", "Anomaly", "Carbon Dioxide (ppm)"]].copy()
annual_co2_temp.corr()
Out[45]:
In [46]:
sns.heatmap(annual_co2_temp.corr())
Out[46]:
<matplotlib.axes._subplots.AxesSubplot at 0x7fcacea9cdd8>
In [47]:
plt.figure(figsize=(10,8))
sns.scatterplot(x="Anomaly",y="Carbon Dioxide (ppm)", data=annual_co2_temp)
Out[47]:
<matplotlib.axes._subplots.AxesSubplot at 0x7fcace8d6c50>
Con la gráfica de calor y la scatter, se nota la relación practicamente lineal del incremento de la temperatura y del Dioxido de Carbono. Ambas están relacionadas en el Cambio climático.
In [ ]:
En el sitio donde se almacenan los datos hay más archivos, temperatura por ciudad por ejemplo para ir más a detalle de la situación por ciudad. También pueden seguir buscando info de otros países, en el artículo original se hizo el de Grecia, y acá probé con Argentina, Brasil, Chile, Canadá, México y Venezuela.
+
+ 
+
+
+ Architecture
+MonkeyUser 10 10 2018
+
+
+
+
+ Government websites
+WhoTracksMe blog 09 10 2018
+
+ 
+
+
+ La libertad de desarrollar...: Generar gráficos animados de burbuja a lo Gapminer con Python
+Python Hispano 07 10 2018
+En febrero de 2013 creé un artículo sobre cómo hacer gráficos de burbujas con matplotlib, la idea era ver como se generaba una gráfica al estilo de la presentación de Hans Rosling (por cierto, murió en Febrero de 2017).
A continuación el vídeo que explica la historia de 200 países en 200 años, la experanza de vida y calida de vida.
O su charla TED sobre sobre las mejores estadísticas que nunca haz visto:
En el artículo que menciono se uso el conjunto de datos de la rata de criminalidad por estado de Estados Unidos del año 2005. Pero sólo mostraba la información y no la variación en el tiempo.
Este artículo se basa en el siguiente tutorial Python Gapminer Animation.
A continuación se muestra el código del script vía notebook de jupyter:
In [1]:
#Se importa las librerias matplitlib, numpy, pandas, seaborn
import matplotlib.pyplot as plt
import numpy as np
import seaborn as sns
sns.set_style("white")
import pandas as pd
my_dpi=96
In [2]:
# Se obtiene los datos en formato csv y se convierte en un dataframe
url = 'https://python-graph-gallery.com/wp-content/uploads/gapminderData.csv'
data = pd.read_csv(url)
In [3]:
#Se muestra el data frame
data.head()
Out[3]:
Tiene las columnas países, año, población, contienen, experanza de vida y pib percapita
In [4]:
#Se revisa los tipos de datos de las columnas
data.info()
Se observa que la columna continente es del tipo objeto. Se necesita convertir en un tipo categoria.
In [5]:
# Transformar los datos de la columna continente a categoria.
data['continent']=pd.Categorical(data['continent'])
data.head()
Out[5]:
In [6]:
#Se vuelve a revisar los tipos de las columnas y ahora se tiene que contienen es categoria
data.info()
Ahora se generará las gráficas por año de experanza de vida y PIB por año, cada gráfica se almacena con su nombre y año a fin de que luego con Image Magick se convierta en un gif animado
In [7]:
# Por cada año
for i in data.year.unique():
# inicializa la figura
fig = plt.figure(figsize=(680/my_dpi, 480/my_dpi), dpi=my_dpi)
# se cambia de color con c y alpha, se mapea el color del eje X.
tmp=data[ data.year == i ]
plt.scatter(tmp['lifeExp'], tmp['gdpPercap'] , s=tmp['pop']/200000 , c=tmp['continent'].cat.codes, cmap="Accent", alpha=0.6, edgecolors="white", linewidth=2)
# Se agrega el título, y los ejes.
plt.yscale('log')
plt.xlabel("Experanza de vida")
plt.ylabel("PIB per capita")
plt.title("Año: "+str(i) )
plt.ylim(0,100000)
plt.xlim(30, 90)
# Se salva el archivo como png, cada archivo por año.
filename='Gapminder_step'+str(i)+'.png'
plt.savefig(filename, dpi=96)
plt.gca()
Se muestra una imagen de las generadas:
Para convertir las imágenes generadas en gif se ejecuta el siguiente comando de image magick:
convert -delay 80 Gapminder*.png animated_gapminder.gif
El gif resultante se muestra a continuación:
En próximo artículo espero encontrar el conjunto de datos del artículo mencionado al inicio para hacerle una animación como el realizado en este artículo.
+
+ These Months in Common Lisp: Q3 2018
+Lisp journey 06 10 2018
+Documentation
+ +-
+
- CLOS – the Common Lisp Cookbook (extensive rewrite) +
- Advanced Use of Lisp’s FORMAT Function (2004) +
- Book: Luger/Stubblefield, 2009; AI Algorithms, Data Structures, and Idioms in Prolog, Lisp, and Java (PDF) +
- GitHub - DalekBaldwin/on-lisp: A modernized and annotated code companion to Paul Graham’s “On Lisp” +
- SLY User Manual, version 1.0.0-beta-2 +
Announcements
+ +-
+
- A new version of Common-Lisp.net has been launched! +
- A new quickdist distribution – Ultralisp.org +
- Autumn Lisp Game Jam +
- SBCL 1.4.12 Released +
- Next Browser Linux Port Campaign +
- awesome-cl.com (the website) +
Jobs
+ + + +Projects
+ +-
+
- Introducing Seed: An Interactive Software Environment in Common Lisp +
- Live reload prototype for clack +
- Mastodon Bot in Common Lisp +
- slack-client: Slack Real Time Messaging API Client +
- cl-progress-bar: Progress bars, just like in quicklisp! +
- Shinmera/oxenfurt: A Common Lisp client library for the Oxford dictionary API +
- flight-recorder - a robust REPL logging facility +
- Music: Music framework for musical expression in Common Lisp with a focus on music theory (built from scratch, on development) +
- Tovero is a 3D modeling system for Common Lisp +
- RMSBolt: See what your compiler is going inside of Emacs (has minimal support for Common Lisp) +
- ftw: Common Lisp Win32 GUI library +
- pngload: A PNG (Portable Network Graphics) image format decoder +
- mel-base - forked and actively updated versatile mail library for common lisp +
- wordnet: Common Lisp interface to WordNet +
- cl-vep: a video effects processor +
- CLiCC - The Common Lisp to C Compiler +
- LIST-NAMED-CLASS - name your CLOS classes with lists, not just symbols +
- GUERRA-ESPACIAL: an implementation of the spacewar computer game in Common Lisp +
- Clive is a Common Lisp binding to Open Inventor with extensions +
- Lorem ipsum generator in portable Common Lisp +
- tlikonen/cl-decimals: Decimal number parser and formatter package +
- tlikonen/cl-enchant: Common Lisp bindings for the Enchant spell-checker library +
- tlikonen/cl-general-accumulator: General-purpose, extensible value accumulator library +
- Drawing UML diagram with Common Lisp +
- slurm-cl - a web application framework for Common Lisp and single page applications. +
new releases:
+ +-
+
- Lem v1.4 has been released with paredit-mode +
- Common Lisp OS Mezzano – Demo 4 +
- Mito ORM: new deftable shortcut to create default initargs, accessors and metaclass +
- Quickref open-sourced - Didier Verna’s Sci-Blog +
(re)discoveries:
+ +-
+
- Shuffletron, a Common Lisp Music Player for the terminal +
- quid-pro-quo: a contract programming library in the style of Eiffel’s Design by Contract +
- Successful Lisp: How to Understand and Use Common Lisp (Book download from Author’s site) +
- Cognitive Robot Abstract Machine = Common Lisp + ROS +
- cl-yaclyaml - a YaML processor (loader, not dumper) +
- Esrap - a packrat parser for Common Lisp +
- gendl - Generative Programming and Knowledge-based Engineering (KBE) system embedded in Common Lisp +
- pcostanza/filtered-functions: an extension of CLOS generic function invocation that enables the use of arbitrary predicates for selecting and applying methods. +
Articles
+ +-
+
- A Road to Common Lisp / Steve Losh +
- Excavating a Common Treasure: Common Lisp +
- First RISCy Steps – Porting SBCL to the RISC-V +
- My pattern to write a web application in Common Lisp (3) +
- A new way of blogging about Common Lisp +
- Going Serverless: From Common LISP and CGI to AWS Lambda and API Gateway +
- Fun with Macros: If-Let and When-Let / Steve Losh +
- How to enable reader macros throughout a project with ASDF’s package-inferred-system (E. Fukamachi) +
- Extempore - The design, implementation and application of a cyber-physical programming language, Andrew Sorensen, Thesis, 2018 (PDF) +
- https://www.ifosslr.org/ojs/ifosslr/article/view/75 +
- Uniform Structured Syntax, Metaprogramming and Run-time Compilation +
- Simple expression evaluator comparison between Haskell, Rust, and Common Lisp +
- Lisping at JPL +
- A Clon guide +
- Common LISP as Simulation Program (CLASP) of Electronic Circuits (2011) (pdf) +
- Lisp code for Christopher Riesbeck’s cs325 AI course. +
- A Story of (defun games ()) +
Discussion
+ +-
+
- What are you working on this week ? +
- CL bad for native GUIs? And other thoughts on first CL project +
Learning Lisp:
+ +-
+
- I want to try Lisp, how should I begin? +
- What lisp dialect for “real world” applications? +
- What do commercial Lisps offer that frees don’t? +
- Which (non-Clojure) Lisp to learn first? +
- Can CL implement Clojure’s keyword as function syntax? +
- Why cons cells? +
Screencasts
+ +-
+
- Little bits of Lisp - cl-autowrap +
- Lots of bits of Lisp - Generating Bindings to C Libraries +
- Lots of bits of Lisp - Macros (2 hr episode) +
- Pushing Pixels with Lisp - Episode 59 - Basic Disolve Shaders (and more episodes !) +
- Common Lisp Study Group - Introduction to Screamer +
- Common Lisp Study Group: An Intro to SERIES +
- Daniel G Bobrow: Common LISP Object Standard 1987 (video 53min) +
Common Lisp VS …
+ + + +
+
+ CLOS Tutorial
+Lisp journey 05 10 2018
+We just updated the CLOS page on the Common Lisp Cookbook. You should refer to it for updates.
+ +CLOS is the “Common Lisp Object System”, arguably one of the most +powerful object systems available in any language.
+ +Some of its features include:
+ +-
+
- it is dynamic, making it a joy to work with in a Lisp REPL. For +example, changing a class definition will update the existing +objects, given certain rules which we have control upon. +
- it supports multiple dispatch and multiple inheritance, +
- it is different from most object systems in that class and method +definitions are not tied together, +
- it has excellent introspection capabilities, +
- it is provided by a meta-object protocol, which provides a +standard interface to the CLOS, and can be used to create new object +systems. +
The functionality belonging to this name was added to the Common Lisp +language between the publication of Steele’s first edition of “Common +Lisp, the Language” in 1984 and the formalization of the language as +an ANSI standard ten years later.
+ +This page aims to give a good understanding of how to use CLOS, but +only a brief introduction to the MOP.
+ +To learn the subjects in depth, you will need two books:
+ +-
+
- Object-Oriented Programming in Common Lisp: a Programmer’s Guide to CLOS, by Sonya Keene, +
- the Art of the Metaobject Protocol, by Gregor Kiczales, Jim des Rivières et al. +
But see also
+ +-
+
- the introduction in Practical Common Lisp (online), by Peter Seibel. +
- Common Lisp, the Language +
- and for reference, the complete CLOS-MOP specifications. +
Table of Contents
+ +-
+
- Classes and instances + + +
- Methods + + +
- MOP + + +
Classes and instances
+ +Diving in
+ +Let’s dive in with an example showing class definition, creation of +objects, slot access, methods specialized for a given class, and +inheritance.
+ +(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)
+ (lisper
+ :initform nil
+ :accessor lisper)))
+
+;; => #<STANDARD-CLASS PERSON>
+
+(defvar p1 (make-instance 'person :name "me" ))
+;; ^^^^ initarg
+;; => #<PERSON {1006234593}>
+
+(name p1)
+;;^^^ accessor
+;; => "me"
+
+(lisper p1)
+;; => nil
+;; ^^ initform (slot unbound by default)
+
+(setf (lisper p1) t)
+
+
+(defclass child (person)
+ ())
+
+(defclass child (person)
+ ((can-walk-p
+ :accessor can-walk-p
+ :initform t)))
+;; #<STANDARD-CLASS CHILD>
+
+(can-walk-p (make-instance 'child))
+;; T
+Defining classes (defclass)
+ +The macro used for defining new data types in CLOS is defclass.
We used it like this:
+ +(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)
+ (lisper
+ :initform nil
+ :accessor lisper)))
+This gives us a CLOS type (or class) called person and two slots,
+named name and lisper.
(class-of p1)
+#<STANDARD-CLASS PERSON>
+
+(type-of p1)
+PERSON
+The general form of defclass is:
(defclass <class-name> (list of super classes)
+ ((slot-1
+ :slot-option slot-argument)
+ (slot-2, etc))
+ (:optional-class-option
+ :another-optional-class-option))
+So, our person class doesn’t explicitely inherit from another class
+(it gets the empty parentheses ()). However it still inherits by default from
+the class t and from standard-object. See below under
+“inheritance”.
We could write a minimal class definition without slots options like this:
+ +(defclass point ()
+ (x y z))
+or even without slots specificiers: (defclass point () ()).
Creating objects (make-instance)
+ +We create instances of a class with make-instance:
(defvar p1 (make-instance 'person :name "me" ))
+It is generally good practice to define a constructor:
+ +(defun make-person (name &key lisper)
+ (make-instance 'person :name name :lisper lisper))
+This has the direct advantage that you can control the required +arguments. You should now export the constructor from your package and +not the class itself.
+ +Slots
+ +A function that always works (slot-value)
+ +The function to access any slot anytime is (slot-value <object> <slot-name>).
Given our point class above, which didn’t define any slot accessors:
(defvar pt (make-instance 'point))
+
+(inspect pt)
+The object is a STANDARD-OBJECT of type POINT.
+0. X: "unbound"
+1. Y: "unbound"
+2. Z: "unbound"
+We got an object of type POINT, but slots are unbound by
+default: trying to access them will raise an UNBOUND-SLOT
+condition:
(slot-value pt 'x) ;; => condition: the slot is unbound
+slot-value is setf-able:
(setf (slot-value pt 'x) 1)
+(slot-value pt 'x) ;; => 1
+Initial and default values (initarg, initform)
+ +-
+
:initarg :foois the keyword we can pass tomake-instanceto +give a value to this slot:
+
(make-instance 'person :name "me")
+(again: slots are unbound by default)
+ +-
+
:initform <val>is the default value in case we didn’t specify +an initarg. This form is evaluated each time it’s needed, in the +lexical environment of thedefclass.
+
Sometimes we see the following trick to clearly require a slot:
+ +(defclass foo ()
+ ((a
+ :initarg :a
+ :initform (error "you didn't supply an initial value for slot a"))))
+;; #<STANDARD-CLASS FOO>
+
+(make-instance 'foo) ;; => enters the debugger.
+Getters and setters (accessor, reader, writer)
+ +-
+
:accessor foo: an accessor is both a getter and a +setter. Its argument is a name that will become a generic +function.
+
(name p1) ;; => "me"
+
+(type-of #'name)
+STANDARD-GENERIC-FUNCTION
+-
+
:readerand:writerdo what you expect. Only the:writerissetf-able.
+
If you don’t specify any of these, you can still use slot-value.
You can give a slot more than one :accessor, :reader or :initarg.
We introduce two macros to make the access to slots shorter in some situations:
+ +1- with-slots allows to abbreviate several calls to slot-value. The
+first argument is a list of slot names. The second argument evaluates
+to a CLOS instance. This is followed by optional declarations and an
+implicit progn. Lexically during the evaluation of the body, an
+access to any of these names as a variable is equivalent to accessing
+the corresponding slot of the instance with slot-value.
(with-slots (name lisper)
+ c1
+ (format t "got ~a, ~a~&" name lisper))
+or
+ +(with-slots ((n name)
+ (l lisper))
+ c1
+ (format t "got ~a, ~a~&" n l))
+2- with-accessors is equivalent, but instead of a list of slots it
+takes a list of accessor functions. Any reference to the variable
+inside the macro is equivalent to a call to the accessor function.
(with-accessors ((name name)
+ ^^variable ^^accessor
+ (lisper lisper))
+ p1
+ (format t "name: ~a, lisper: ~a" name lisper))
+Class VS instance slots
+ +:allocation specifies whether this slot is local or shared.
-
+
a slot is local by default, that means it can be different for each instance of the class. In that case
:allocationequals:instance.
+
+a shared slot will always be equal for all instances of the +class. We set it with
:allocation :class.
+
In the following example, note how changing the value of the class
+slot species of p2 affects all instances of the
+class (whether or not those instances exist yet).
(defclass person ()
+ ((name :initarg :name :accessor name)
+ (species
+ :initform 'homo-sapiens
+ :accessor species
+ :allocation :class)))
+
+;; Note that the slot "lisper" was removed in existing instances.
+(inspect p1)
+;; The object is a STANDARD-OBJECT of type PERSON.
+;; 0. NAME: "me"
+;; 1. SPECIES: HOMO-SAPIENS
+;; > q
+
+(defvar p2 (make-instance 'person))
+
+(species p1)
+(species p2)
+;; HOMO-SAPIENS
+
+(setf (species p2) 'homo-numericus)
+;; HOMO-NUMERICUS
+
+(species p1)
+;; HOMO-NUMERICUS
+
+(species (make-instance 'person))
+;; HOMO-NUMERICUS
+
+(let ((temp (make-instance 'person)))
+ (setf (species temp) 'homo-lisper))
+;; HOMO-LISPER
+(species (make-instance 'person))
+;; HOMO-LISPER
+Slot documentation
+ +Each slot accepts one :documentation option.
Slot type
+ +The :type slot option may not do the job you expect it does. If you
+are new to the CLOS, we suggest you skip this section and use your own
+constructors to manually check slot types.
Indeed, whether slot types are being checked or not is undefined. See the Hyperspec.
+ +Few implementations will do it. Clozure CL does it, SBCL does it when
+safety is high ((declaim (optimize safety))).
To do it otherwise, see this Stack-Overflow answer, and see also quid-pro-quo, a contract programming library.
+ +find-class, class-name, class-of
+ +(find-class 'point)
+;; #<STANDARD-CLASS POINT 275B78DC>
+
+(class-name (find-class 'point))
+;; POINT
+
+(class-of my-point)
+;; #<STANDARD-CLASS POINT 275B78DC>
+
+(typep my-point (class-of my-point))
+;; T
+CLOS classes are also instances of a CLOS class, and we can find out +what that class is, as in the example below:
+ +(class-of (class-of my-point))
+;; #<STANDARD-CLASS STANDARD-CLASS 20306534>
+Note: this is your first introduction to the MOP. You don’t need that to get started !
+ +The object my-point is an instance of the class named point, and the
+class named point is itself an instance of the class named
+standard-class. We say that the class named standard-class is
+the metaclass (i.e. the class of the class) of
+my-point. We can make good uses of metaclasses, as we’ll see later.
Subclasses and inheritance
+ +As illustrated above, child is a subclass of person.
All objects inherit from the class standard-object and t.
Every child instance is also an instance of person.
(type-of c1)
+;; CHILD
+
+(subtypep (type-of c1) 'person)
+;; T
+
+(ql:quickload "closer-mop")
+;; ...
+
+(closer-mop:subclassp (class-of c1) 'person)
+;; T
+The closer-mop library is the +portable way to do CLOS/MOP operations.
+ +A subclass inherits all of its parents slots, and it can override any +of their slot options. Common Lisp makes this process dynamic, great +for REPL session, and we can even control parts of it (like, do +something when a given slot is removed/updated/added, etc).
+ +The class precedence list of a child is thus:
child <- person <-- standard-object <- t
+Which we can get with:
+ +(closer-mop:class-precedence-list (class-of c1))
+;; (#<standard-class child>
+;; #<standard-class person>
+;; #<standard-class standard-object>
+;; #<sb-pcl::slot-class sb-pcl::slot-object>
+;; #<sb-pcl:system-class t>)
+However, the direct superclass of a child is only:
(closer-mop:class-direct-superclasses (class-of c1))
+;; (#<standard-class person>)
+We can further inspect our classes with
+class-direct-[subclasses, slots, default-initargs] and many more functions.
How slots are combined follows some rules:
+ +-
+
:accessorand:readerare combined by the union of accessors +and readers from all the inherited slots.
+
+:initarg: the union of initialization arguments from all the +inherited slots.
+
+:initform: we get the most specific default initial value +form, i.e. the first:initformfor that slot in the precedence +list.
+
+:allocationis not inherited. It is controlled solely by the class +being defined and defaults to:instance.
+
Last but not least, be warned that inheritance is fairly easy to
+misuse, and multiple inheritance is multiply so, so please take a
+little care. Ask yourself whether foo really wants to inherit from
+bar, or whether instances of foo want a slot containing a bar. A
+good general guide is that if foo and bar are “same sort of thing”
+then it’s correct to mix them together by inheritance, but if they’re
+really separate concepts then you should use slots to keep them apart.
Multiple inheritance
+ +CLOS supports multiple inheritance.
+ +(defun baby (child person)
+ ())
+The first class on the list of parent classes is the most specific
+one, child’s slots will take precedence over the person’s
TODO (but +remember how slots are merged).
+ +Redefining and changing a class
+ +This section briefly covers two topics:
+ +-
+
- redefinition of an existing class, which you might already have done +by following our code snippets, and what we do naturally during +development, and +
- changing an instance of one class into an instance of another, +a powerful feature of CLOS that you’ll probably won’t use very often. +
We’ll gloss over the details. Suffice it to say that everything’s +configurable by implementing methods exposed by the MOP.
+ +To redefine a class, simply evaluate a new defclass form. This then
+takes the place of the old definition, the existing class object is
+updated, and all instances of the class (and, recursively, its
+subclasses) are lazily updated to reflect the new definition. You don’t
+have to recompile anything other than the new defclass, nor to
+invalidate any of your objects. Think about it for a second: this is awesome !
For example, with our person class:
(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)
+ (lisper
+ :initform nil
+ :accessor lisper)))
+
+(setf p1 (make-instance 'person :name "me" ))
+Changing, adding, removing slots,…
+ +(lisper p1)
+;; NIL
+
+(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)
+ (lisper
+ :initform t ;; <-- from nil to t
+ :accessor lisper)))
+
+(lisper p1)
+;; NIL (of course!)
+
+(lisper (make-instance 'person :name "You"))
+;; T
+
+(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)
+ (lisper
+ :initform nil
+ :accessor lisper)
+ (age
+ :initarg :arg
+ :initform 18
+ :accessor age)))
+
+(age p1)
+;; => slot unbound error. This is different from "slot missing":
+
+(slot-value p1 'bwarf)
+;; => "the slot bwarf is missing from the object #<person…>"
+
+(setf (age p1) 30)
+(age p1) ;; => 30
+
+(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)))
+
+(slot-value p1 'lisper) ;; => slot lisper is missing.
+(lisper p1) ;; => there is no applicable method for the generic function lisper when called with arguments #(lisper).
+To change the class of an instance, use change-class:
(change-class p1 'child)
+;; we can also set slots of the new class:
+(change-class p1 'child :can-walk-p nil)
+
+(class-of p1)
+;; #<STANDARD-CLASS CHILD>
+
+(can-walk-p p1)
+;; T
+In the above example, I became a child, and I inherited the can-walk-p slot, which is true by default.
Pretty printing
+ +Everytime we printed an object so far we got an output like
+ +#<PERSON {1006234593}>
+which doesn’t say much.
+ +What if we want to show more information ? Something like
+ +#<PERSON me lisper: t>
+Pretty printing is done by specializing the generic print-object method for this class:
(defmethod print-object ((obj person) stream)
+ (print-unreadable-object (obj stream :type t)
+ (with-accessors ((name name)
+ (lisper lisper))
+ obj
+ (format stream "~a, lisper: ~a" name lisper))))
+It gives:
+ +p1
+;; #<PERSON me, lisper: T>
+print-unreadable-object prints the #<...>, that says to the reader
+that this object can not be read back in. Its :type t argument asks
+to print the object-type prefix, that is, PERSON. Without it, we get
+#<me, lisper: T>.
We used the with-accessors macro, but of course for simple cases this is enough:
(defmethod print-object ((obj person) stream)
+ (print-unreadable-object (obj stream :type t)
+ (format stream "~a, lisper: ~a" (name obj) (lisper obj))))
+Caution: trying to access a slot that is not bound by default will
+lead to an error. Use slot-boundp.
For reference, the following reproduces the default behaviour:
+ +(defmethod print-object ((obj person) stream)
+ (print-unreadable-object (obj stream :type t :identity t)))
+Here, :identity to t prints the {1006234593} address.
Classes of traditional lisp types
+ +Where we approach that we don’t need CLOS objects to use CLOS.
+ +Generously, the functions introduced in the last section also work on +lisp objects which are not CLOS instances:
+ +(find-class 'symbol)
+;; #<BUILT-IN-CLASS SYMBOL>
+(class-name *)
+;; SYMBOL
+(eq ** (class-of 'symbol))
+;; T
+(class-of ***)
+;; #<STANDARD-CLASS BUILT-IN-CLASS>
+We see here that symbols are instances of the system class
+symbol. This is one of 75 cases in which the language requires a
+class to exist with the same name as the corresponding lisp
+type. Many of these cases are concerned with CLOS itself (for
+example, the correspondence between the type standard-class and
+the CLOS class of that name) or with the condition system (which
+might or might not be built using CLOS classes in any given
+implementation). However, 33 correspondences remain relating to
+“traditional” lisp types:
|array|hash-table|readtable|
+|bit-vector|integer|real|
+|broadcast-stream|list|sequence|
+|character|logical-pathname|stream|
+|complex|null|string|
+|concatenated-stream|number|string-stream|
+|cons|package|symbol|
+|echo-stream|pathname|synonym-stream|
+|file-stream|random-state|t|
+|float|ratio|two-way-stream|
+|function|rational|vector|
Note that not all “traditional” lisp types are included in this
+list. (Consider: atom, fixnum, short-float, and any type not
+denoted by a symbol.)
The presence of t is interesting. Just as every lisp
+object is of type t, every lisp object is also a member
+of the class named t. This is a simple example of
+membership of more then one class at a time, and it brings into
+question the issue of inheritance, which we will consider
+in some detail later.
(find-class t)
+;; #<BUILT-IN-CLASS T 20305AEC>
+In addition to classes corresponding to lisp types, there is also a + CLOS class for every structure type you define:
+ +(defstruct foo)
+FOO
+
+(class-of (make-foo))
+;; #<STRUCTURE-CLASS FOO 21DE8714>
+The metaclass of a structure-object is the class
+ structure-class. It is implementation-dependent whether
+ the metaclass of a “traditional” lisp object is
+ standard-class, structure-class, or
+ built-in-class. Restrictions:
|built-in-class| May not use make-instance, may not use slot-value, may not use defclass to modify, may not create subclasses.|
+|structure-class| May not use make-instance, might work with slot-value (implementation-dependent). Use defstruct to subclass application structure types. Consequences of modifying an existing structure-class are undefined: full recompilation may be necessary.|
+|standard-class|None of these restrictions.|
Introspection
+ +we already saw some introspection functions.
+ +Your best option is to discover the +closer-mop libray and to +keep the CLOS & MOP specifications at +hand.
+ +More functions:
+ +closer-mop:class-default-initargs
+closer-mop:class-direct-default-initargs
+closer-mop:class-direct-slots
+closer-mop:class-direct-subclasses
+closer-mop:class-direct-superclasses
+closer-mop:class-precedence-list
+closer-mop:class-slots
+closer-mop:classp
+closer-mop:extract-lambda-list
+closer-mop:extract-specializer-names
+closer-mop:generic-function-argument-precedence-order
+closer-mop:generic-function-declarations
+closer-mop:generic-function-lambda-list
+closer-mop:generic-function-method-class
+closer-mop:generic-function-method-combination
+closer-mop:generic-function-methods
+closer-mop:generic-function-name
+closer-mop:method-combination
+closer-mop:method-function
+closer-mop:method-generic-function
+closer-mop:method-lambda-list
+closer-mop:method-specializers
+closer-mop:slot-definition
+closer-mop:slot-definition-allocation
+closer-mop:slot-definition-initargs
+closer-mop:slot-definition-initform
+closer-mop:slot-definition-initfunction
+closer-mop:slot-definition-location
+closer-mop:slot-definition-name
+closer-mop:slot-definition-readers
+closer-mop:slot-definition-type
+closer-mop:slot-definition-writers
+closer-mop:specializer-direct-generic-functions
+closer-mop:specializer-direct-methods
+closer-mop:standard-accessor-method
+See also
+ +defclass/std: write shorter classes
+ +The library defclass/std
+provides a macro to write shorter defclass forms.
By default, it adds an accessor, an initarg and an initform to nil to your slots definition:
This:
+ +(defclass/std example ()
+ ((slot1 slot2 slot3)))
+expands to:
+ +(defclass example ()
+ ((slot1
+ :accessor slot1
+ :initarg :slot1
+ :initform nil)
+ (slot2
+ :accessor slot2
+ :initarg :slot2
+ :initform nil)
+ (slot3
+ :accessor slot3
+ :initarg :slot3
+ :initform nil)))
+It does much more and it is very flexible, however it is seldom used +by the Common Lisp community: use at your own risks©.
+ +Methods
+ +Diving in
+ +Recalling our person and child classes from the beginning:
(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)))
+;; => #<STANDARD-CLASS PERSON>
+
+(defclass child (person)
+ ())
+;; #<STANDARD-CLASS CHILD>
+
+(setf p1 (make-instance 'person :name "me"))
+(setf c1 (make-instance 'child :name "Alice"))
+Below we create methods, we specialize them, we use method combination +(before, after, around), and qualifiers.
+ +(defmethod greet (obj)
+ (format t "Are you a person ? You are a ~a.~&" (type-of obj)))
+;; style-warning: Implicitly creating new generic function common-lisp-user::greet.
+;; #<STANDARD-METHOD GREET (t) {1008EE4603}>
+
+(greet :anything)
+;; Are you a person ? You are a KEYWORD.
+;; NIL
+(greet p1)
+;; Are you a person ? You are a PERSON.
+
+(defgeneric greet (obj)
+ (:documentation "say hello"))
+;; STYLE-WARNING: redefining COMMON-LISP-USER::GREET in DEFGENERIC
+;; #<STANDARD-GENERIC-FUNCTION GREET (2)>
+
+(defmethod greet ((obj person))
+ (format t "Hello ~a !~&" (name obj)))
+;; #<STANDARD-METHOD GREET (PERSON) {1007C26743}>
+
+(greet p1) ;; => "Hello me !"
+(greet c1) ;; => "Hello Alice !"
+
+(defmethod greet ((obj child))
+ (format t "ur so cute~&"))
+;; #<STANDARD-METHOD GREET (CHILD) {1008F3C1C3}>
+
+(greet p1) ;; => "Hello me !"
+(greet c1) ;; => "ur so cute"
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; Method combination: before, after, around.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defmethod greet :before ((obj person))
+ (format t "-- before person~&"))
+#<STANDARD-METHOD GREET :BEFORE (PERSON) {100C94A013}>
+
+(greet p1)
+;; -- before person
+;; Hello me
+
+(defmethod greet :before ((obj child))
+ (format t "-- before child~&"))
+;; #<STANDARD-METHOD GREET :BEFORE (CHILD) {100AD32A43}>
+(greet c1)
+;; -- before child
+;; -- before person
+;; ur so cute
+
+(defmethod greet :after ((obj person))
+ (format t "-- after person~&"))
+;; #<STANDARD-METHOD GREET :AFTER (PERSON) {100CA2E1A3}>
+(greet p1)
+;; -- before person
+;; Hello me
+;; -- after person
+
+(defmethod greet :after ((obj child))
+ (format t "-- after child~&"))
+;; #<STANDARD-METHOD GREET :AFTER (CHILD) {10075B71F3}>
+(greet c1)
+;; -- before child
+;; -- before person
+;; ur so cute
+;; -- after person
+;; -- after child
+
+(defmethod greet :around ((obj child))
+ (format t "Hello my dear~&"))
+;; #<STANDARD-METHOD GREET :AROUND (CHILD) {10076658E3}>
+(greet c1) ;; Hello my dear
+
+
+;; call-next-method
+
+(defmethod greet :around ((obj child))
+ (format t "Hello my dear~&")
+ (when (next-method-p)
+ (call-next-method)))
+;; #<standard-method greet :around (child) {100AF76863}>
+
+(greet c1)
+;; Hello my dear
+;; -- before child
+;; -- before person
+;; ur so cute
+;; -- after person
+;; -- after child
+
+;;;;;;;;;;;;;;;;;
+;; Adding in &key
+;;;;;;;;;;;;;;;;;
+
+;; In order to add "&key" to our generic method, we need to remove its definition first.
+(fmakunbound 'greet) ;; with Slime: C-c C-u (slime-undefine-function)
+(defmethod greet ((obj person) &key talkative)
+ (format t "Hello ~a~&" (name obj))
+ (when talkative
+ (format t "blah")))
+
+(defgeneric greet (obj &key &allow-other-keys)
+ (:documentation "say hi"))
+
+(defmethod greet (obj &key &allow-other-keys)
+ (format t "Are you a person ? You are a ~a.~&" (type-of obj)))
+
+(defmethod greet ((obj person) &key talkative &allow-other-keys)
+ (format t "Hello ~a !~&" (name obj))
+ (when talkative
+ (format t "blah")))
+
+(greet p1 :talkative t) ;; ok
+(greet p1 :foo t) ;; still ok
+
+
+;;;;;;;;;;;;;;;;;;;;;;;
+
+(defgeneric greet (obj)
+ (:documentation "say hello")
+ (:method (obj)
+ (format t "Are you a person ? You are a ~a~&." (type-of obj)))
+ (:method ((obj person))
+ (format t "Hello ~a !~&" (name obj)))
+ (:method ((obj child))
+ (format t "ur so cute~&")))
+
+;;;;;;;;;;;;;;;;
+;;; Specializers
+;;;;;;;;;;;;;;;;
+
+(defgeneric feed (obj meal-type)
+ (:method (obj meal-type)
+ (declare (ignorable meal-type))
+ (format t "eating~&")))
+
+(defmethod feed (obj (meal-type (eql :dessert)))
+ (declare (ignorable meal-type))
+ (format t "mmh, dessert !~&"))
+
+(feed c1 :dessert)
+;; mmh, dessert !
+
+(defmethod feed ((obj child) (meal-type (eql :soup)))
+ (declare (ignorable meal-type))
+ (format t "bwark~&"))
+
+(feed p1 :soup)
+;; eating
+(feed c1 :soup)
+;; bwark
+Generic functions (defgeneric, defmethod)
+ +A generic function is a lisp function which is associated
+with a set of methods and dispatches them when it’s invoked. All
+the methods with the same function name belong to the same generic
+function.
The defmethod form is similar to a defun. It associates a body of
+code with a function name, but that body may only be executed if the
+types of the arguments match the pattern declared by the lambda list.
They can have optional, keyword and &rest arguments.
The defgeneric form defines the generic function. If we write a
+defmethod without a corresponding defgeneric, a generic function
+is automatically created (see examples).
It is generally a good idea to write the defgenerics. We can add a
+default implementation and even some documentation.
(defgeneric greet (obj)
+ (:documentation "says hi")
+ (:method (obj)
+ (format t "Hi")))
+The required parameters in the method’s lambda list may take one of +the following three forms:
+ +1- a simple variable:
+ +(defmethod greet (foo)
+ ...)
+This method can take any argument, it is always applicable.
+ +The variable foo is bound to the corresponding argument value, as
+usual.
2- a variable and a specializer, as in:
+ +(defmethod greet ((foo person))
+ ...)
+In this case, the variable foo is bound to the corresponding
+argument only if that argument is of specializer class person or a subclass,
+like child (indeed, a “child” is also a “person”).
If any argument fails to match its +specializer then the method is not applicable and it cannot be +executed with those arguments.We’ll get an error message like +“there is no applicable method for the generic function xxx when +called with arguments yyy”.
+ +Only required parameters can be specialized. We can’t specialize on optional &key arguments.
3- a variable and an eql specializer
+ +(defmethod feed ((obj child) (meal-type (eql :soup)))
+ (declare (ignorable meal-type))
+ (format t "bwark~&"))
+
+(feed c1 :soup)
+;; "bwark"
+In place of a simple symbol (:soup), the eql specializer can be any
+lisp form. It is evaluated at the same time of the defmethod.
You can define any number of methods with the same function name but
+with different specializers, as long as the form of the lambda list is
+congruent with the shape of the generic function. The system chooses
+the most specific applicable method and executes its body. The most
+specific method is the one whose specializers are nearest to the head
+of the class-precedence-list of the argument (classes on the left of
+the lambda list are more specific). A method with specializers is more
+specific to one without any.
Notes:
+ +-
+
It is an error to define a method with the same function name as +an ordinary function. If you really want to do that, use the +shadowing mechanism.
+
+To add or remove
keysorrestarguments to an existing generic +method’s lambda list, you will need to delete its declaration with +fmakunbound(orC-c C-u(slime-undefine-function) with the +cursor on the function in Slime) and start again. Otherwise, +you’ll see:
+
attempt to add the method
+ #<STANDARD-METHOD NIL (#<STANDARD-CLASS CHILD>) {1009504233}>
+to the generic function
+ #<STANDARD-GENERIC-FUNCTION GREET (2)>;
+but the method and generic function differ in whether they accept
+&REST or &KEY arguments.
+-
+
Methods can be redefined (exactly as for ordinary functions).
+
+The order in which methods are defined is irrelevant, although +any classes on which they specialize must already exist.
+
+An unspecialized argument is more or less equivalent to being +specialized on the class
t. The only difference is that +all specialized arguments are implicitly taken to be “referred to” (in +the sense ofdeclare ignore.)
+
+Each
defmethodform generates (and returns) a CLOS +instance, of classstandard-method.
+
+An
eqlspecializer won’t work as is with strings. Indeed, strings +needequalorequalpto be compared. But, we can assign our string +to a variable and use the variable both in theeqlspecializer and +for the function call.
+
+All the methods with the same function name belong to the same generic function.
+
+All slot accessors and readers defined by
defclassare methods. They can override or be overridden by other methods on the same generic function.
+
See more about defmethod on the CLHS.
+ +Multimethods
+ +Multimethods explicitly specialize more than one of the generic +function’s required parameters.
+ +They don’t belong to a particular class. Meaning, we don’t have to +decide on the class that would be best to host this method, as we might +have to in other languages.
+ +(defgeneric hug (a b)
+ (:documentation "Hug between two persons."))
+;; #<STANDARD-GENERIC-FUNCTION HUG (0)>
+
+(defmethod hug ((a person) (b person))
+ :person-person-hug)
+
+(defmethod hug ((a person) (b child))
+ :person-child-hug)
+Read more on Practical Common Lisp.
+ +Controlling setters (setf-ing methods)
+ +In Lisp, we can define setf counterparts of functions or methods. We
+might want this to have more control on how to update an object.
(defmethod (setf name) (new-val (obj person))
+ (if (equalp new-val "james bond")
+ (format t "Dude that's not possible.~&")
+ (setf (slot-value obj 'name) new-val)))
+
+(setf (name p1) "james bond") ;; -> no rename
+If you know Python, this behaviour is provided by the @property decorator.
Dispatch mechanism and next methods
+ +When a generic function is invoked, the application cannot directly invoke a method. The dispatch mechanism proceeds as follows:
+ +-
+
- compute the list of applicable methods +
- if no method is applicable then signal an error +
- sort the applicable methods in order of specificity +
- invoke the most specific method. +
Our greet generic function has three applicable methods:
(closer-mop:generic-function-methods #'greet)
+(#<STANDARD-METHOD GREET (CHILD) {10098406A3}>
+ #<STANDARD-METHOD GREET (PERSON) {1009008EC3}>
+ #<STANDARD-METHOD GREET (T) {1008E6EBB3}>)
+During the execution of a method, the remaining applicable methods
+are still accessible, via the local function
+call-next-method. This function has lexical scope within
+the body of a method but indefinite extent. It invokes the next most
+specific method, and returns whatever value that method returned. It
+can be called with either:
-
+
no arguments, in which case the next method will +receive exactly the same arguments as this method did, or
+
+explicit arguments, in which case it is required that the +sorted set of methods applicable to the new arguments must be the same +as that computed when the generic function was first called.
+
For example:
+ +(defmethod greet ((obj child))
+ (format t "ur so cute~&")
+ (when (next-method-p)
+ (call-next-method)))
+;; STYLE-WARNING: REDEFINING GREET (#<STANDARD-CLASS CHILD>) in DEFMETHOD
+;; #<STANDARD-METHOD GREET (child) {1003D3DB43}>
+
+(greet c1)
+;; ur so cute
+;; Hello Alice !
+Calling call-next-method when there is no next method
+signals an error. You can find out whether a next method exists by
+calling the local function next-method-p (which also has
+has lexical scope and indefinite extent).
Note finally that the body of every method establishes a block with the same name as the method’s generic function. If you return-from that name you are exiting the current method, not the call to the enclosing generic function.
Method qualifiers (before, after, around)
+ +In our “Diving in” examples, we saw some use of the :before, :after and :around qualifiers:
-
+
(defmethod foo :before (obj) (...))
+(defmethod foo :after (obj) (...))
+(defmethod foo :around (obj) (...))
+
By default, in the standard method combination framework provided by +CLOS, we can only use one of those three qualifiers, and the flow of control is as follows:
+ +-
+
- a before-method is called, well, before the applicable primary +method. If they are many before-methods, all are called. The +most specific before-method is called first (child before person). +
- the most specific applicable primary method (a method without +qualifiers) is called (only one). +
- all applicable after-methods are called. The most specific one is +called last (after-method of person, then after-method of child). +
The generic function returns the value of the primary method. Any +values of the before or after methods are ignored. They are used for +their side effects.
+ +And then we have around-methods. They are wrappers around the core +mechanism we just described. They can be useful to catch return values +or to set up an environment around the primary method (set up a catch, +a lock, timing an execution,…).
+ +If the dispatch mechanism finds an around-method, it calls it and
+returns its result. If the around-method has a call-next-method, it
+calls the next most applicable around-method. It is only when we reach
+the primary method that we start calling the before and after-methods.
Thus, the full dispatch mechanism for generic functions is as follows:
+ +-
+
- compute the applicable methods, and partition them into +separate lists according to their qualifier; +
- if there is no applicable primary method then signal an +error; +
- sort each of the lists into order of specificity; +
- execute the most specific
:aroundmethod and +return whatever that returns;
+ - if an
:aroundmethod invokes +call-next-method, execute the next most specific +:aroundmethod;
+
+ if there were no
+ +:aroundmethods in the first +place, or if an:aroundmethod invokes +call-next-methodbut there are no further +:aroundmethods to call, then proceed as follows:a. run all the
+ +:beforemethods, in order, + ignoring any return values and not permitting calls to +call-next-methodor +next-method-p;b. execute the most specific primary method and return + whatever that returns;
+ +c. if a primary method invokes
+ +call-next-method, + execute the next most specific primary method;d. if a primary method invokes
+ +call-next-method+ but there are no further primary methods to call then signal an + error;e. after the primary method(s) have completed, run all the +
:aftermethods, in reverse + order, ignoring any return values and not permitting calls to +call-next-methodor +next-method-p.
+
Think of it as an onion, with all the :around
+ methods in the outermost layer, :before and
+ :after methods in the middle layer, and primary methods
+ on the inside.
Other method combinations
+ +The default method combination type we just saw is named standard,
+but other method combination types are available, and no need to say
+that you can define your own.
The built-in types are:
+ +progn + list nconc and max or append min
+You notice that these types are named after a lisp operator. Indeed,
+what they do is they define a framework that combines the applicable
+primary methods inside a call to the lisp operator of that name. For
+example, using the progn combination type is equivalent to calling all
+the primary methods one after the other:
(progn
+ (method-1 args)
+ (method-2 args)
+ (method-3 args))
+Here, unlike the standard mechanism, all the primary methods +applicable for a given object are called, the most specific +first.
+ +To change the combination type, we set the :method-combination
+option of defgeneric and we use it as the methods’ qualifier:
(defgeneric foo (obj)
+ (:method-combination progn))
+
+(defmethod foo progn ((obj obj))
+ (...))
+An example with progn:
+ +(defgeneric dishes (obj)
+ (:method-combination progn)
+ (:method progn (obj)
+ (format t "- clean and dry.~&"))
+ (:method progn ((obj person))
+ (format t "- bring a person's dishes~&"))
+ (:method progn ((obj child))
+ (format t "- bring the baby dishes~&")))
+;; #<STANDARD-GENERIC-FUNCTION DISHES (3)>
+
+(dishes c1)
+;; - bring the baby dishes
+;; - bring a person's dishes
+;; - clean and dry.
+
+(greet c1)
+;; ur so cute --> only the most applicable method was called.
+Similarly, using the list type is equivalent to returning the list
+of the values of the methods.
(list
+ (method-1 args)
+ (method-2 args)
+ (method-3 args))
+(defgeneric tidy (obj)
+ (:method-combination list)
+ (:method list (obj)
+ :foo)
+ (:method list ((obj person))
+ :books)
+ (:method list ((obj child))
+ :toys))
+;; #<STANDARD-GENERIC-FUNCTION TIDY (3)>
+
+(tidy c1)
+;; (:toys :books :foo)
+Around methods are accepted:
+ +(defmethod tidy :around (obj)
+ (let ((res (call-next-method)))
+ (format t "I'm going to clean up ~a~&" res)
+ (when (> (length res)
+ 1)
+ (format t "that's too much !~&"))))
+
+(tidy c1)
+;; I'm going to clean up (toys book foo)
+;; that's too much !
+Note that these operators don’t support before, after and around
+methods (indeed, there is no room for them anymore). They do support
+around methods, where call-next-method is allowed, but they don’t
+support calling call-next-method in the primary methods (it would
+indeed be redundant since all primary methods are called, or clunky to
+not call one).
CLOS allows us to define a new operator as a method combination type, be +it a lisp function, macro or special form. We’ll let you refer to the +books if you feel the need.
+ +Debugging: tracing method combination
+ +It is possible to trace the method +combination, but this is implementation dependent.
+ +In SBCL, we can use (trace foo :methods t). See this post by an SBCL core developer.
For example, given a generic:
+ +(defgeneric foo (x)
+ (:method (x) 3))
+(defmethod foo :around ((x fixnum))
+ (1+ (call-next-method)))
+(defmethod foo ((x integer))
+ (* 2 (call-next-method)))
+(defmethod foo ((x float))
+ (* 3 (call-next-method)))
+(defmethod foo :before ((x single-float))
+ 'single)
+(defmethod foo :after ((x double-float))
+ 'double)
+Let’s trace it:
+ +(trace foo :methods t)
+
+(foo 2.0d0)
+ 0: (FOO 2.0d0)
+ 1: ((SB-PCL::COMBINED-METHOD FOO) 2.0d0)
+ 2: ((METHOD FOO (FLOAT)) 2.0d0)
+ 3: ((METHOD FOO (T)) 2.0d0)
+ 3: (METHOD FOO (T)) returned 3
+ 2: (METHOD FOO (FLOAT)) returned 9
+ 2: ((METHOD FOO :AFTER (DOUBLE-FLOAT)) 2.0d0)
+ 2: (METHOD FOO :AFTER (DOUBLE-FLOAT)) returned DOUBLE
+ 1: (SB-PCL::COMBINED-METHOD FOO) returned 9
+ 0: FOO returned 9
+9
+MOP
+ +We gather here some examples that make use of the framework provided +by the meta-object protocol, the configurable object system that rules +Lisp’s object system. We touch advanced concepts so, new reader, don’t +worry: you don’t need to understand this section to start using the +Common Lisp Object System.
+ +We won’t explain much about the MOP here, but hopefully sufficiently +to make you see its possibilities or to help you understand how some +CL libraries are built. We invite you to read the books referenced in +the introduction.
+ +Metaclasses
+ +Metaclasses are needed to control the behaviour of other classes.
+ +As announced, we won’t talk much. See also Wikipedia for metaclasses or CLOS.
+ +The standard metaclass is standard-class:
(class-of p1) ;; #<STANDARD-CLASS PERSON>
+But we’ll change it to one of our own, so that we’ll be able to +count the creation of instances. This same mechanism could be used +to auto increment the primary key of a database system (this is +how the Postmodern or Mito libraries do), to log the creation of objects, +etc.
+ +Our metaclass inherits from standard-class:
(defclass counted-class (standard-class)
+ ((counter :initform 0)))
+#<STANDARD-CLASS COUNTED-CLASS>
+
+(unintern 'person)
+;; this is necessary to change the metaclass of person.
+;; or (setf (find-class 'person) nil)
+;; https://stackoverflow.com/questions/38811931/how-to-change-classs-metaclass#38812140
+
+(defclass person ()
+ ((name
+ :initarg :name
+ :accessor name)
+ (:metaclass counted-class))) ;; <- metaclass
+;; #<COUNTED-CLASS PERSON>
+;; ^^^ not standard-class anymore.
+The :metaclass class option can appear only once.
Actually you should have gotten a message asking to implement
+validate-superclass. So, still with the closer-mop library:
(defmethod closer-mop:validate-superclass ((class counted-class)
+ (superclass standard-class))
+ t)
+Now we can control the creation of new person instances:
(defmethod make-instance :after ((class counted-class) &key)
+ (incf (slot-value class 'counter)))
+;; #<STANDARD-METHOD MAKE-INSTANCE :AFTER (COUNTED-CLASS) {1007718473}>
+See that an :after qualifier is the safest choice, we let the
+standard method run as usual and return a new instance.
The &key is necessary, remember that make-instance is given initargs.
Now testing:
+ +(defvar p3 (make-instance 'person :name "adam"))
+#<PERSON {1007A8F5B3}>
+
+(slot-value p3 'counter)
+;; => error. No, our new slot isn't on the person class.
+(slot-value (find-class 'person) 'counter)
+;; 1
+
+(make-instance 'person :name "eve")
+;; #<PERSON {1007AD5773}>
+(slot-value (find-class 'person) 'counter)
+;; 2
+It’s working.
+ +Controlling the initialization of instances (initialize-instance)
+ +To further customize the creation of instances by specializing
+initialize-instance, which is called by make-instance, just after
+it has created a new instance but didn’t initialize it yet with the
+default initargs and initforms.
It is recommended (Keene) to create an after method, since creating a +primary method would prevent slots’ initialization.
+ +(defmethod initialize-instance :after ((obj person) &key)
+ (do something with obj))
+Another rational. The CLOS implementation of
+ make-instance is in two stages: allocate the new object,
+ and then pass it along with all the make-instance keyword
+ arguments, to the generic function
+ initialize-instance. Implementors and application writers
+ define :after methods on
+ initialize-instance, to initialize the slots of the
+ instance. The system-supplied primary method does this with regard to
+ (a) :initform and :initarg values supplied
+ with the class was defined and (b) the keywords passed through from
+ make-instance. Other methods can extend this behaviour as
+ they see fit. For example, they might accept an additional keyword
+ which invokes a database access to fill certain slots. The lambda list
+ for initialize-instance is:
initialize-instance instance &rest initargs &key &allow-other-keys
+See more in the books !
+ +
+
+ September 2018 Monthly Update
+News on Clojurists Together 04 10 2018
+
+ 
+
+
+ Applied TDD
+MonkeyUser 02 10 2018
+
+
+ ¿Dejadez? ¿Desfachatez? ¿Desconocimiento? ¿Desinterés? Vertidos en Canarias.
+Andanzas de una ambientóloga . . . 01 10 2018
+
+
+ Q4 2018 Survey Results and Call For Proposals
+News on Clojurists Together 30 09 2018
+
+
+ Volvemos! Wangari Muta Maathai.
+Andanzas de una ambientóloga . . . 26 09 2018
+
+ 
+
+
+ Tech Debt
+MonkeyUser 25 09 2018
+
+
+ Setting Up Hugo on Netlify
+(ノ°Д°）ノ︵ ┻━┻ 24 09 2018
+
+ 
+
+
+ Setting Up Hugo on Netlify
+(ノ°Д°）ノ︵ ┻━┻ 24 09 2018
++Hugo is a static site generator that just like another alternatives(Nicola, Jekyll, etc) allows to write in plain text and generate html, js, css files.
+
+Hugo is so much simpler to use because it's a simple binary file, called hugo, that allows to develop and prepare the site to be published. Some of its features are:
-
+
-
+
Generate a new site
+
+ -
+
Run a development server
+
+ -
+
Generate static files
+
+ -
+
Generate new pages for the site
+
+
So let's start to build a site from scratch and publish it automatically using Netlify
+
+
++Creating the new site +
+
+
++First we'll need to install hugo. You need to install the single binary using the package manager you prefer. In mac OS you can install it using Homebrew with the following command:
+
+brew install hugo
+You can check the version with hugo version, at the time I'm writing this post the latest version available is 0.48.
+Now we need to generate an new empty site so we'll use the command hugo new site myblog. Once the command finished you'll have a new folder called myblog
+The structure of the new folder should be:
+
+
+
+├── archetypes
+│ └── default.md
+├── config.toml
+├── content
+├── data
+├── layouts
+├── static
+└── themes
+For now we have to pay attention to only one file config.toml this file contains the configuration of the new site. We can define stuff like the title of the blog, menus structure, theme parameters, etc.
+The contents of config.toml should be like this:
+
+
+baseURL = "http://example.org/"
+languageCode = "en-us"
+title = "My New Hugo Site"
+We have to change baseURL to / to avoid error with broken links(we'll see these possible errors later). So the result config.toml will be:
+
+
+baseURL = "/"
+languageCode = "en-us"
+title = "My New Hugo Site"
+
++Adding a theme +
+
+
++Now we have to install a theme. There are many awesome themes available for Hugo. You can check and pick one in Hugo themes.
++For this example we'll use Beautiful Hugo
++We have 2 options to include the theme in the new site:
+-
+
-
+
Clone the theme repository and add it to our folder. This will copy all the files inside our folder.
+
+ -
+
Use git sub modules to create a reference to the theme repository. This way we don't need to copy all the files.
+
+
We'll use the second option this time.
+
+First we need to initialize a git repository inside our myblog folder using the following command git init. Now we have a git repository created.
+Now we have to run the following commands to add the theme:
+
+
+
+cd themes
+git submodule add https://github.com/halogenica/beautifulhugo.git
+cd ..
+This will clone the theme repository and add it to our repository as a submodule. We can see that now we have a beautifulhugo folder inside themes folder and also there is a new file in the root of myblog called .gitmodules with the following content:
+
+
+[submodule "themes/beautifulhugo"]
+ path = themes/beautifulhugo
+ url = https://github.com/halogenica/beautifulhugo.git
+Now we have to tell hugo we want to use this theme in the new site, we'll do this adding the following lines to the config.toml file:
+
+
+theme = "beautifulhugo"
+
++Running the development server +
+
+
+
+To see the new site running before publish it we'll use the embedded development server. We run it with hugo server -D -p 9000.
+After that we'll an output similar to this:
+
+
+
+ | EN
++------------------+----+
+ Pages | 7
+ Paginator pages | 0
+ Non-page files | 0
+ Static files | 33
+ Processed images | 0
+ Aliases | 1
+ Sitemaps | 1
+ Cleaned | 0
+
+Total in 46 ms
+Watching for changes in /Users/erick/Code/hugo/myblog/{content,data,layouts,static,themes}
+Watching for config changes in /Users/erick/Code/hugo/myblog/config.toml
+Serving pages from memory
+Running in Fast Render Mode. For full rebuilds on change: hugo server --disableFastRender
+Web Server is available at http://localhost:9000/ (bind address 127.0.0.1)
+Press Ctrl+C to stop+Now we can open the browser and enter http://localhost:9000 and we'll see the new site with the chosen theme.
++The server is watching for changes to be compiled so we leave it running.
+
+
++Writing content +
+
+
++At this point we don't have any content to show up so let's create some.
++Hugo by default can render Markdown and Org-mode files. For this example we'll create a new post using markdown format.
+
+Run hugo new post/hello-world.md to create a new file called hello-world.md in content/post/, Hugo will create a new file with the following content:
+
+
+---
+title: "Hello World"
+date: 2018-09-22T15:05:47-05:00
+draft: true
+---+These lines are used by Hugo to show details about the content in the result file.
+
+Let's add the lines below to hello-world.md
+
+
+# This is a heading with level 1
+
+## This is a heading with level 2
+
+This is a paragraph
+
+This is some python code
+
+This is a list:
+
+- item 1
+- item 2
+Now if we go to the browser we'll see the home page with a summary of the content of hello-world.md
+By default Hugo show a list of the posts created in content/post in the homepage. Now we can enter to the post to see the full content.
+Once we finished with the post it's necessary remove draft: true from hello-world.md file otherwise the file won't show up when we publish the site.
+
+
+ +Publishing the site +
+
+
+
+
++Uploading the site to a remote repository +
+
+
++We can use Github, Gitlab or Bitbucket to do this. These are the services supported by Netlify. For this example I've uploaded the repository to Github and it's available in https://github.com/erickgnavar/hugo-demo-site.
+
+
++Creating an account in Netlify +
+
+
++Now we have to create an account in Netlify, there is a free plan that we can use to host the new site.
+
+
++Deploying site +
+
+
++Once we have the Netlify account and the site uploaded in a external repository we can proceed with the deploy.
++Now we can log in and start the process clicking in "New site from Git".
+
+Then there are 3 steps to follow:
+
+
++Connect to git provider +
+
+
++We have to log in using the service where we uploaded the site.
+
+
++Pick a repository +
+
+
++Now we have access an a list of our repositories. We can search for the one where the site is in.
+
+
++Build options +
+
+
++Once we chosen the repository we can specify the build options. Netlify recognize that the site is made with Hugo so these options are already configured.
++To proceed we click in "Deploy site".
+
+
++Deploy result +
+
+
++Netlify will pull the repository and compile the site with the given build options and then it will generate a url to access the deployed site.
+
+Now we can go to the url that Netlify generated for the site and we'll see the resulting site.
+
+
++Useful Netlify configuration +
+
+
++By default Netlify only will build the site when we push changes to master. We can change this going to "Deploy settings" and changing "Branch deploys" options to "All" like the following image:
+
+With this configuration we can push changes to a different branch than master and Netlify will generate a new url to see the changes. This is useful to test changes before publish them to production site.
+It's also possible configure different kind of notifications(Slack, email, etc) to receive the result of the deploy.
+
+
+ About me
+(ノ°Д°）ノ︵ ┻━┻ 22 09 2018
+
+ 
+
+
+ Compromise
+MonkeyUser 18 09 2018
+
+
+ Be Careful With CTE in PostgreSQL
+Haki Benita 16 09 2018
+Common table expressions, also known as the WITH clause, are a very useful feature. They help break down big queries into smaller pieces which makes it easier to read and understand. But, when used incorrectly they can cause a significant performance hit.
+
+
+ Adding click-to-copy buttons to a Hugo powered blog
+Blogs on Tom Spencer 14 09 2018
+
+
+ Adding click-to-copy buttons to a Hugo powered blog
+Blogs on Tom Spencer 14 09 2018
+
+ 
+
+
+ Shuffletron, a Common Lisp Music Player for the terminal
+Lisp journey 11 09 2018
+Shuffletron is a nice music +player for the terminal written in Common Lisp, “based on search and +tagging”, that seduced me with its attention to details. Moreover, its +author was very responsive to fix a couple issues.
+ +The first time you launch it, it will ask for a music repository and
+will propose to scan it for id3 tags with the scanid3 command. It
+is optional, but it allows to print colored information:
The basic commands to know are the following:
+ +-
+
search with
/followed by your search terms. You’ll notice that +your prompt changed fromlibrarytoxy matches. You can refine +the results by searching again. To enter a new query we have to go +back to the library, with as many successive “enters” as needed.
+
+to play songs:
+ +play. We can select which songs to play, using their index:-
+
- comma-separated indexes of songs:
1,3,10
+ - a selection with a dash and an optional end:
1-10,0-
+ - a combination of the two:
1,3-10.
+
+
+- comma-separated indexes of songs:
there are the obvious
pause,shuffle,skip,next,seek,repeat,…
+
+nowto show the currently playing song.
+
There is also a queue, id3 tags management, profiles to
+use an alternate library (./shuffletron --help), and even an alarm
+clock feature which allows to program music with something like:
alarm at 7:45 am # \"at\" is optional and doesn't change the meaning
+ alarm 7:45 am
+ alarm 9 pm
+ alarm 7 # If AM/PM not specified, assumes AM
+ alarm in 5 minutes # Relative alarm times, in minutes or hours
+ alarm in 10m # minutes, minute, mins, min, , m are synonyms
+ alarm in 7 hours # hours, hour, hr, h are synonyms
+ alarm in 8h
+ alarm in 7:29 # h:mm format - seven hours, twenty-nine minutes
+ alarm reset # off/never/delete/disable/cancel/clear/reset
+I can see a use for a pomodoro-like technic :)
+ +I’ll list the complete set of commands below (available +on the sources), +but first a note on installation.
+ +Installation
+ +Shuffletron doesn’t provide executables +(yet ?). The +procedure is now documented in the readme so you just have to
+ +make shuffletron-bin # sbcl
+sudo make install
+./shuffletron
+This last line calls a script and it is actually important to use it,
+to link dependencies and to use rlwrap. There is room for
+improvement here.
To read Flac and Ogg files, you need those system dependencies:
+ +apt install libflac-dev
+apt install libvorbis-dev
+Finally, scanning my library failed for the first time, because of +badly manually encoded ogg files coming from youtube. The mixalot +library prefered to fail instead of showing error messages. If you +encounter a similar problem, see +this PR.
+ +All commands
+ +In the application, type help, and help commands to get this list:
Command list:
+
+ /[query] Search library for [query].
+ show Print search matches, highlighting songs in queue.
+ back Undo last search.
+ [songs] Play list of songs.
+ all Play all songs in selection (equivalent to \"0-\")
+ +[songs] Append list of songs to queue.
+ pre[songs] Prepend list of songs to queue.
+ random Play a random song from the current selection.
+ random QUERY Play a random song matching QUERY
+ shuffle SONGS Play songs in random order.
+
+ queue Print queue contents and current song playing.
+ shuffle Randomize order of songs in queue.
+ clear Clear the queue (current song continues playing)
+ loop Toggle loop mode (loop through songs in queue)
+ qdrop Remove last song from queue
+ qdrop RANGES Remove songs from queue
+ qtag TAGS Apply tags to all songs in queue
+ fromqueue Transfer queue to selection
+ toqueue Replace queue with selection
+
+ now Print name of song currently playing.
+ play Resume playing
+ stop Stop playing (current song pushed to head of queue)
+ pause Toggle paused/unpaused.
+ skip Skip currently playing song. If looping is enabled, this
+ song won't played again.
+ next Advance to next song. If looping is enabled, the current
+ song will be enqueued.
+ repeat N Add N repetitions of currently playing song to head of queue.
+ seek TIME Seek to time (in [h:]m:ss format, or a number in seconds)
+ seek +TIME Seek forward
+ seek -TIME Seek backward
+ startat TIME Always start playback at a given time (to skip long intros)
+
+ tag List tags of currently playing song.
+ tag TAGS Add one or more textual tags to the current song.
+ untag TAGS Remove the given tags from the currently playing song.
+ tagged TAGS Search for files having any of specified tags.
+ tags List all tags (and # occurrences) within current query.
+ killtag TAGS Remove all occurances of the given tags
+ tagall TAGS Apply tags to all selected songs
+ untagall TAGS Remove given tags from all selected songs
+
+ time Print current time
+ alarm Set alarm (see \"help alarms\")
+
+ scanid3 Scan new files for ID3 tags
+ prescan Toggle file prescanning (useful if file IO is slow)
+ exit Exit the program.
+
+ help [topic] Help
+See also
+ +-
+
- mpd, an interface to Music Player +Daemon in CL. +
other music players:
+ +-
+
- cmus +
- Emacs’ media players http://wikemacs.org/wiki/Media_player +
+ 
+
+
+ Final Patch
+MonkeyUser 11 09 2018
+
+
+ August 2018 Monthly Update
+News on Clojurists Together 06 09 2018
+
+
+ Freak Spot: Subprocesos en Python
+Python Hispano 04 09 2018
+Los subprocesos o hilos de +ejecución nos +permiten realizar tareas concurrentemente. En Python podemos utilizar el +módulo threading, +aunque hay muchos otros.
+Vamos a crear varios subprocesos (threads) sencillos.
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+import threading
+import time
+import random
+
+def sleeper(name, s_time):
+ print('{} iniciado a las {}.'.format(
+ name, time.strftime('%H:%M:%S', time.gmtime())))
+
+ time.sleep(s_time)
+
+ print('{} finalizado a las {}.'.format(
+ name, time.strftime('%H:%M:%S', time.gmtime())))
+
+
+for i in range(5):
+ thread = threading.Thread(target=sleeper, args=(
+ 'Proceso ' + str(i + 1), random.randint(1, 9)))
+
+ thread.start()
+
+print('Yo he terminado, pero los otros subprocesos no.')
+Primero, hemos importado los modulos necesarios: time, random y
+threading. Para crear threads solo necesitamos el último. time lo
+hemos utilizado para simular una tarea y obtener su tiempo de inicio y
+fin; random, para hacer que nuestro proceso tenga una duración
+aleatoria.
La función sleeper «duerme» (no hace nada) durante el tiempo que le +especifiquemos, nos dice cuándo ha empezado a «dormir» y cuando ha +terminado de «dormir». Como parámetros le pasamos el nombre que le +queremos dar al subproceso y el tiempo que va a «dormir» la función.
+Luego, creamos un bucle for que crea 5 subprocesos que ejecutan la
+función sleeper. En el constructor (threading.Thread), debemos
+indicar la función a ejecutar (target=sleeper) y los parámetros que
+queremos pasarle
+(args=('Proceso ' + str(i + 1), random.randint(1, 9)).
Proceso 1 iniciado a las 21:19:23.
+Proceso 2 iniciado a las 21:19:23.
+Proceso 3 iniciado a las 21:19:23.
+Proceso 4 iniciado a las 21:19:23.
+Proceso 5 iniciado a las 21:19:23.
+Yo he terminado, pero los otros subprocesos no.
+Proceso 1 finalizado a las 21:19:25.
+Proceso 5 finalizado a las 21:19:26.
+Proceso 4 finalizado a las 21:19:27.
+Proceso 2 finalizado a las 21:19:32.
+Proceso 3 finalizado a las 21:19:32.
+El resultado de la ejecución es aleatorio: no sabemos cuál proceso +finalizará primero.
+
+
+
+
+ GDPR - What happened?
+WhoTracksMe blog 02 09 2018
+
+ 
+
+
+ Building a raft
+MonkeyUser 28 08 2018
+
+
+
+
+ Third-party cookies - the guests who won't leave
+WhoTracksMe blog 26 08 2018
+
+ 
+
+
+ Implementation
+MonkeyUser 21 08 2018
+
+
+ July 2018 Monthly Update
+News on Clojurists Together 14 08 2018
+
+ 
+
+
+ Macro
+MonkeyUser 14 08 2018
+
+ 
+
+
+ Join me on Mastodon
+Danny van Kooten 13 08 2018
+++ +Summary: Join me on Mastodon. It’s like Twitter, but less angry and more decentralized.
+
I’ve been a happy Twitter user for years and got a lot of value out of it over the last decade. Even so, I find myself using the service very little these days.
+ +While I can’t say for certain what is the cause of that, the non-chronological timeline and algorithms that seem to excel at showing me rage-inducing tweets come to mind. An extensive mute list helped for a little while, but even that is falling short nowadays.
+ +That’s part of why I was happily surprised when revisiting Mastodon a few weeks ago.
+ +A lot had improved since I last checked in early 2017. I connected to a few people that seemed to be sharing interesting content, found some I already knew and had a really good time exploring the “fediverse” since then.
+ +Why Mastodon?
+ +Here’s a few things that make Mastodon great for me:
+ +-
+
- It’s open-source and you can host it yourself, while still participating in the global network and following users on other instances. +
- Your feed is chronological, ad-free and there are no algorithms deciding what you actually end up seeing. +
- You get 500 characters per “toot” and can hide things behind spoiler warnings. +
A sample of what it could look like (although there are many different clients)
+ +
I’m enthusiastic about the direction that Mastodon is heading in and am really enjoying myself on there already. If you’re looking for a place that feels a bit like Twitter in the early days, give Mastodon a proper try.
+ +To further promote decentralization, I decided to run my own instance: mastodon.dvk.co (which was super easy to set up, by the way).
+ +Useful Mastodon tools
+ +If you’re new to Mastodon, you’ll have to put in some effort to turn it into something useful. It’s not much fun logging in to an empty feed after all.
+ +Here are some of the tools that helped me:
+ + + + +
+
+ The next ten years of Instapaper
+Instapaper 07 08 2018
+This year Instapaper celebrated its tenth birthday and, now that we are an independent company, we’ve been thinking a lot about the next ten years of Instapaper and beyond.
To ensure Instapaper can continue for the foreseeable future, it’s essential that the product generates enough revenue to cover its costs. In order to do so, we’re relaunching Instapaper Premium today.
As a reminder, Instapaper Premium is a subscription for $2.99/month or $29.99/year that offers the following features:
- Full-text search for all articles in your account
- Unlimited Notes
- Text-to-Speech playlists on mobile
- Speed reading to get through all of your articles up to 3x faster
- An ad-free Instapaper website
- “Send to Kindle” using a bookmarklet or our mobile apps
In addition to getting access to Premium features, your Instapaper Premium subscription will help ensure that we can continue developing and operating Instapaper. Our goal is to build a long-term sustainable product and business, without venture capital, and we need your help to achieve that goal.
If you decide to not subscribe to Instapaper Premium, you will continue with a standard free account without access to Premium features.
Additionally, today we are bringing back Instapaper to European Union users. Over the past two months we have taken a number of actions to address the General Data Protection Regulation, and we are happy to announce our return to the European Union.
We are very sorry for the extended downtime and, as a token of our apology, we are giving six months of Instapaper Premium to all EU users affected by the outage.
We’ve updated our privacy policy to include the rights afforded to EU users under the General Data Protection Regulation (GDPR). Additionally, in the interest of transparency, we are posting our privacy policy to GitHub where you can view a versioned history of all the changes to our privacy policy.
Thanks again for your support. If you have any questions, comments or concerns please let us know by sending an email to support@help.instapaper.com.
– Brian Donohue & Rodion Gusev
+
+
+ How to deal with dirty side effects in your pure functional JavaScript
+James Sinclair 07 08 2018
+
+
+ How to deal with dirty side effects in your pure functional JavaScript
+Web Development - James Sinclair 07 08 2018
+
+ 
+
+
+ Blame
+MonkeyUser 07 08 2018
+
+
+ Deploying a Hugo-powered site to Netlify with source code syntax highlighting
+Blogs on Tom Spencer 03 08 2018
+
+
+ Deploying a Hugo-powered site to Netlify with source code syntax highlighting
+Blogs on Tom Spencer 03 08 2018
+
+
+ Q4 2018 Funding Announcement
+News on Clojurists Together 03 08 2018
+
+
+ Q3 2018 Funding Announcement
+News on Clojurists Together 03 08 2018
+
+ 
+
+
+ Pull Request
+MonkeyUser 31 07 2018
+
+ 
+
+
+ Define Madness
+MonkeyUser 25 07 2018
+
+
+ Hyperreals *R: Borrado de un descriptor (corrección de errores)
+Python Hispano 24 07 2018
+Tengo que hacer algunas correcciones a la serie de artículos sobre descriptores, en concreto sobre el método __delete__ del protocolo descriptor.
Primero, aclaremos cómo funciona el método __delete__ y en qué se diferencia de __del__. No se trata de métodos destructores tal y como se entiende en otros lenguajes de programación orientados a objeto. En python, todo objeto está vivo mientras esté referenciado. Sólo cuando se pierda la última referencia se procederá a la destrucción y borrado del objeto en memoria por parte del recolector de basura.
Por ejemplo, veamos el siguiente código:
+class Miclase(object):
+
+ def __del__(self):
+ print "instance deleted"
+
+a = Miclase()
+b = a
+del a
+
+print b
+print "Come on"
+b = 1
+print "END"
+De su ejecución, podemos comprobar que el método __del__ no se invoca justo en el momento de hacer del a, si no cuando se pierde la última referencia al asignar otro valor a la variable b. La sentencia del a no destruye el objeto, tan sólo desliga el objeto de la etiqueta a que lo referenciaba. Por ese motivo, es inexacto hablar en python de “variable de memoria”, como se entiende en otro lenguajes. Tan sólo cambiamos de una referencia de un objeto a otro, sin destruir su valor anterior.
Revisión del protocolo descriptor
+En un anterior artículo distinguía entre descriptores de datos y de no-datos. Hay que aclarar que un descriptor de datos “es también el que sólo tiene definido un método __delete__, aunque no tenga método __set__“. ¿Para qué puede sernos útil tener uno sin el otro?
Un descriptor de datos sin método __set__ no tiene forma de impedir que el atributo/método que implementa sea sustituído por otro objeto (por ejemplo, por otro descriptor). El método __delete__ nos daría la última opción de liberar recursos que ya no vayamos a usar antes de desaparecer el descriptor. Pero, independiemente de lo que haga, el método __delete__ indicaría que el descriptor puede ser sustituido. En definitiva, se comportaría como un descriptor de no-datos, pero con las diferencias en la invocación entre estos dos tipos de descriptor1.
Para aclarar las cosas, veamos qué estaba mal en el ejemplo que puse en su momento sobre el uso de __delete__ (he cambiado algunos nombres para que se vea más claro):
class Desc(object):
+
+ def __init__(self, mul):
+ self.mul = mul
+
+ def __get__(self, obj, cls=None):
+ return obj.value * self.mul
+
+ def __set__(self, obj, value):
+ raise AttributeError
+
+ def __delete__(self, obj):
+ del self
+
+class Miclase(object):
+
+ a12 = Desc(12)
+ a200 = Desc(200)
+
+ def __init__(self, value):
+ self.value = value
+
+
+c = Miclase(2)
+
+print c.a12 #--> 24
+
+c.a12 = 100 # ERROR: AttributeError
+
+del Miclase.a12
+c.a12=100
+
+print c.a12 #--> 100 (no descriptor)
+La idea era que se pudiera borrar el descriptor de datos para sustuirlo por otro valor. Tal como señalaba Cristian en un comentario al respecto, este ejemplo parece funcionar con o sin el método __delete__ en el descriptor.
Funciona siempre debido a que con 'del Miclase.a12' estamos borrando la referencia al descriptor que tiene la clase, sin pasar por el protocolo descriptor. La particularidad de los descriptores es que viven en la clase, pero se invocan desde la instancia. Con 'del Miclase.a12' estamos saltándonos el protocolo descriptor para acceder directamente al atributo de la clase2.
Además, este código no funcionaría nunca:
+ def __delete__(self, obj):
+ del self
+Si la idea era borrar el objeto self, referencia al descriptor, podemos quitarnos esa idea ya que el comando del borra la referencia del scope local donde se encuentra. ¡No es un destructor! En realidad, todas las variables locales son borradas al finalizar el método. En este caso en concreto, también la variable local obj será borrada aunque no se indique explícitamente.
Otra cuestión a tener en cuenta es que los atributos de clase son compartidos por todas sus instancias. Si en algún momento alteramos un descriptor (por ejemplo, borrándolo), entonces todas las instancias sufririan el mismo cambio. No parece que sea el efecto buscado.
+La gran pregunta es entonces, ¿cómo podemos aprovecharnos del método __delete__?
Para sacarle algún partido, el descriptor debería comportarse de forma distinta según sea la instancia que lo invoca. Definido así el descriptoor, entonces podríamos usar el método __delete__ para simular el borrado del atributo para esa instancia, sin que el descriptor pierda su funcionalidad.
Un ejemplo para ilustrar ésto sería:
+from weakref import WeakKeyDictionary
+
+class Desc(object):
+
+ def __init__(self):
+ self.data = WeakKeyDictionary()
+
+ def __get__(self, obj, cls=None):
+ if obj not in self.data:
+ raise AttributeError
+ total = sum(x for x in self.data.values())
+ return (self.data.get(obj), total)
+
+ def __set__(self, obj, value):
+ if obj in self.data:
+ raise AttributeError
+ self.data[obj] = value
+
+ def __delete__(self, obj):
+ del self.data[obj]
+
+class Miclase(object):
+
+ value = Desc()
+
+
+a = Miclase()
+b = Miclase()
+
+a.value = 2
+b.value = 5
+
+print a.value #--> (2, 7)
+print b.value #--> (5, 7)
+
+a.value = 100 # ERROR: AttributeError
+
+del a.value
+a.value = 11
+
+print a.value #--> (11, 16)
+print b.value #--> (5, 16)
+
+del b
+
+print a.value #--> (11, 11)
+El descriptor mantiene un diccionario weak con valores asignados para cada instancia de la clase. Usamos para ello un WeakKeyDictionary que tiene la particularidad de relajar la referencia al objeto, de modo que si todas las referencias al objeto son borradas en el programa, también es borrada la referencia que conservaba el diccionario.
+En este ejemplo, el método __get__ devuelve el valor del atributo si el objeto está en el diccionario, si no da error. El método __set__ asigna un valor al atributo sólo si el objeto no existe. Para ver mejor el funcionamiento, el método __get__ devuelve una tupla con el valor del atributo y la suma de todos los atributos.
Ejecuntado el ejemplo, creamos dos instancias y les asignamos un valor al atributo controlado por el descriptor. Una vez asignado un valor, ya no podemos cambiarlo. La única opción será borrar el atributo y volverlo a asignar.
+También se puede comprobar que, cuando borramos el objeto b, la suma de todos los atributos se actualiza a las instancias que aún quedan vivas.
En el borrado del atributo se usa el método __delete__ del descriptor; en el borrado de la instancia, el método __del__ (si existiera).
Referencia
+No quisiera acabar este artículo sin añadir una referencia sobre este tema que os recomiendo leer, con algunas recetas para aprovechar el uso de los descriptores:
+“Python Descriptors Demystified” by Chris Beaumont
+
+
+
+ +
-
+
-
+
Comentado en los anteriores artículos sobre descriptores. ↩
+
+ -
+
Un modo de impedir el borrado de atributos de una clase sería aplicando el protocolo descriptor con metaclases, pero pienso que estaríamos complicándolo todo demasiado para el beneficio que pudiera obtenerse a cambio. ↩
+
+
+
+ Hyperreals *R: Mutable o inmutable, he ahí el dilema
+Python Hispano 24 07 2018
+
+
+Info
+Disponible también como ipynb
+Quien se enfrenta a la documentación de python por primera vez se pregunta porqué esa insistencia en mantener tipos de datos duplicados en versiones mutables e inmutables. Tenemos listas y tuplas que casi hacen lo mismo. En python3, tenemos el tipo inmutable bytes y el mutable bytearray. ¿Qué sentido tiene tener “duplicados” algunos tipos en sus dos versiones? La única explicación que se puede encontrar en la documentación es que los tipos inmutables son más apropiados para usarlos como índices en diccionarios. No parece mucha ventaja para la complejidad que aporta.
En este artículo veremos qué implica la mutabilidad de un tipo de dato y en qué puede sernos útil usar un tipo mutable u otro inmutable.
+¿Qué es lo que cambia?
+Antes de explicar nada, veamos si somos capaces de saber qué está cambiando. Veamos dos códigos muy similares:
+>>> a = (1, 2, 3, 4)
+>>> a += (5, 6, 7)
+>>> print(a)
+(1, 2, 3, 4, 5, 6, 7)
+>>> a = [1, 2, 3, 4]
+>>> a += [5, 6, 7]
+>>> print( a )
+Parece que ambos códigos hagan lo mismo: añadir un fragmento, en sus versiones tupla y lista, respectivamente. Vamos a analizarlo mejor. Para saber qué pasa, usemos la función id(). Esta función devuelve un identificador de un objeto de tal modo que si dos objetos tienen el mismo identificador, entonces son el mismo objeto.
>>> a = (1, 2, 3, 4)
+>>> print(id(a))
+192021604
+>>> a += (5, 6, 7)
+>>> print(id(a))
+189519828
+>>> a = [1, 2, 3, 4]
+>>> print(id(a))
+189780876
+>>> a += [5, 6, 7]
+>>> print(id(a))
+189780876
+En la versión tupla, se ha creado una nueva tupla para realizar la operación, mientras que en la versión lista se ha usado la misma lista, modificándose con el resultado. Si cambiamos el operador += por una versión más explícita tal vez se vea mejor:
>>> a = (1, 2, 3, 4)
+>>> a = a + (5, 6, 7)
+>>> a = [1, 2, 3, 4]
+>>> a.extend([5, 6, 7])
+Al operar con tuplas, los operandos no cambian de valor, creándose una nueva tupla como resultado de la operación. Podríamos sustituir toda la operación por el resultado final y el código funcionaría igual. En el caso de las listas, la lista se modifica “in situ” durante la operación. En estos casos, cambiar la expresión por el resultado final no garantiza que el programa funcione igual. Se necesita pasar por todos y cada uno de los estados intermedios para asegurar que todo funcione igual.
+Esta propiedad de poder cambiar una expresión por su resultado final es conocida por Transparencia referencial en programación funcional. Por lo general, los tipos inmutables se adecúan mejor a operaciones de cálculo donde el resultado final depende únicamente de los argumentos de entrada. Por otro lado, los tipos mutables son útiles para salvaguardar estados intermedios necesarios para la toma de decisiones durante la ejecución de un programa.
+Por lo general, se saber elegir un tipo mutable o su homólogo inmutable es todo un arte. Ante la duda, los tipos inmutables son más fáciles de rastrear. Así mismo, veremos en próximos artículos que los tipos inmutables ayudan bastante en programación concurrente, por si estás pensando en programación multiproceso.
+Ejemplos de tipos propios
+La mutabilidad e inmutabilidad va más allá de los tipos estándar de python. Nosotros mismos podemos hacer nuestras propias clases mutables o inmutables, según nuestras necesidades.
+Pongamos que creamos una clase Point para definir puntos, junto con unas sencillas operaciones para sumar, restar y desplazar. Nuestra idea es poder usar estos objetos en expresiones, por lo que es práctica común que toda operación devuelva el resultado como un punto para seguir encadenando operaciones.
Una versión “mutable” del objeto sería así:
+class PointMutable(object):
+ def __init__(self, x, y):
+ self.x=x
+ self.y=y
+
+ def __repr__(self):
+ return "<Point(%d,%d)>" % (self.x, self.y)
+
+ def __sub__(self, other):
+ self.x -= other.x
+ self.y -= other.y
+ return self
+
+ def __add__(self, other):
+ self.x += other.x
+ self.y += other.y
+ return self
+
+ def move(self, dx, dy):
+ self.x += dx
+ self.y += dy
+ return self
+En todas las operaciones, operamos el objeto consigo mismo y lo retornamos como resultados. Si probamos, vemos que no funciona tal como se esperaba:
+>>> p1=PointMutable(1, 1)
+>>> p2=PointMutable(-1, 1)
+>>> print p1.move(1, 1) - (p1 + p2).move(2, 2)
+<Point(0,0)>
+Devuelve <Point<0,0> independientemente de los valores iniciales y de los desplazamientos que demos. Al ser nuestro objeto mutable, cada operación lo va cambiando. Al final, toda la expresión se reduce a una simple resta p1-p1, que sería la última operación y que da siempre <Point(0,0)>. No parece que sea el resultado esperado.
Debemos adoptar una táctica más defensiva: el objeto nunca debe cambiar durante el cálculo. Como resultado de cada operación deberemos devolver una nueva instancia y que el estado de ésta, o sea, sus atributos, no se alteren a lo largo del cálculo:
+class PointInmutable(object):
+ def __init__(self, x, y):
+ self.x = x
+ self.y = y
+
+ def __repr__(self):
+ return "<Point(%d,%d)>" % (self.x, self.y)
+
+ def __sub__(self, other):
+ return PointInmutable(self.x - other.x, self.y - other.y)
+
+ def __add__(self, other):
+ return PointInmutable(self.x + other.x, self.y + other.y)
+
+ def move(self, dx, dy):
+ return PointInmutable(self.x + dx, self.y + dy)
+>>> p1=PointInmutable(1, 1)
+>>> p2=PointInmutable(-1, 1)
+>>> print p1.move(1, 1) - (p1 + p2).move(2, 2)
+<Point(0,-2)>
+Siendo perfeccionistas, deberíamos blindar mejor los atributos de la clase para hacerlos de sólo lectura mediante properties.
En este ejemplo hemos podido ver los resultados imprevisibles que podemos tener si abusamos de la mutabilidad. Estos problemas se ven incrementados si hubiera varios hilos de ejecución y cada hilo estuviera modificando las mismas variables comunes. Lamentablemente, es un caso bastante común debido a una mala previsión a la hora de iniciar un proyecto de desarrollo. Pero ésto lo veremos en un próximo artículo.
+
+
+ June 2018 Monthly Update
+News on Clojurists Together 18 07 2018
+
+ 
+
+
+ Production Ready
+MonkeyUser 17 07 2018
+
+
+ Instapaper is going independent
+Instapaper 16 07 2018
+Today, we’re announcing that Pinterest has entered into an agreement to transfer ownership of Instapaper to Instant Paper, Inc., a new company owned and operated by the same people who’ve been working on Instapaper since it was sold to betaworks by Marco Arment in 2013. The ownership transfer will occur after a 21 day waiting period designed to give our users fair notice about the change of control with respect to their personal information.
We want to emphasize that not much is changing for the Instapaper product outside the new ownership. The product will continue to be built and maintained by the same people who’ve been working on Instapaper for the past five years. We plan to continue offering a robust service that focuses on readers and the reading experience for the foreseeable future.
Lastly, we want to express our deepest gratitude to Pinterest for being such great stewards of the product over the past two years. With their support, we rebuilt search, introduced an extension for Firefox, made a variety of optimizations for the latest mobile operating systems and more. Our focus is providing a great reading application to our users, we appreciated the opportunity to do that at Pinterest, and are excited to continue our work.
If you have any questions, comments or concerns please let us know by sending an email to support@help.instapaper.com or replying directly to this email.
– Instapaper Team
+
+ 
+
+
+ Programador Web Valencia: Charla sobre Python
+Python Hispano 14 07 2018
+
En el episodio 69 de República Web, Podcast dirigido y escrito por Javier Archeni (@javierarcheni), he tenido el placer de ser invitado para mantener una tertulia animada sobre Python. Entre muchos temas se tocaron:
+ +-
+
- Libros interesantes. +
- El origen del lenguaje. +
- Virtudes. +
- Consejos para novatos. +
- Actualidad sobre el lenguaje. +
- Frameworks como Django o Flask. +
- Usos académicos y empresariales. +
Si es un lenguaje que siempre te ha llamado la atención y sientes curiosidad por ver sus posibilidades, escucha el episodio con mucha atención. No te dejará indiferente. Y no olvides dejar un comentario.
+
+
+ Q3 2018 Survey Results and Call For Proposals
+News on Clojurists Together 12 07 2018
+
+ 
+
+
+ Zeno's Progress
+MonkeyUser 10 07 2018
+
+
+ Learning Rust 02: an ls clone
+Posts on James Routley 08 07 2018
+
+ 
+
+
+ Programador Web Valencia: Qué aporta Python para el desarrollo web
+Python Hispano 04 07 2018
+
Python es un lenguaje sencillo y rápido de aprender. Su sintaxis es parecida a escribir cualquier texto en inglés, pero con la potencia de sus principales competidores en el BackEnd.
+ +Es un placer de leer y redactar. Python predica que un código debe ser escrito por humanos para humanos. Después de todo lo que programas va a ser leído por ti y por el resto del equipo. Si escribes para máquinas, solo te entenderán máquinas.
+ +Además viene con “Pilas incluidas”. Eso quiere decir que posee su propio gestor de paquetes, sin necesidad de instalar aplicaciones externas. Simplificando tareas de instalación o actualización.
+ +Otro punto a su favor es que no necesita un ecosistema para ejecutarse, como puede ser Xampp, Vangrant, Docker… Python solo requieres Python. Lanzando un comando en el terminal estará ejecutándose su propio servidor Web, consiguiendo que su puesta en producción sea sorprendentemente rápida.
+ +Y por si fuera poco, es el segundo lenguajes que mejor esta pagado por las empresas. Por detrás de Ruby.
+ +¿Donde nació Python?
+ +En una navidad de 1989 un programador fue enviado a casa. Sus oficinas iban a estar cerradas durante unas semanas. Esta persona de 33 años, llamada Guido van Rossum, se encontró que solo tenía un solo aparato para entretenerse hasta que acabaran las navidades: un ordenador. Para matar el rato decidió distraerse programando un interprete para un nuevo lenguaje de programación de scripting que había estado teorizando en sus ratos libres. Un heredero de ABC. Sin mucho interés, casi por formalidad, lo bautizó con un nombre sencillo. Él era muy fan de los Monty Python, por lo que lo llamó: Python.
+ +Y aquí es donde nació uno de los lenguajes más expresivos y buque insignia del Código Abierto.
+ +Frameworks Web
+ +Entre sus numerosos y fantásticos Frameworks, nos podemos encontrar unas bestias: Django y Flask (que no confundir que el zombie Adobe Flash).
+ +Django sería lo más cercano a Laravel en PHP o Ruby on Rails para Ruby. Un marco de trabajo completo y eficiente para desarrollar Aplicaciones Web de una gran complejidad con un mínimo esfuerzo. Casi cualquier cosa que necesites posiblemente estará integrado.
+ +Para desarrollos altamente personalizados o con unos tiempos cortos, nos encontramos a Flask. Autodenominado microframework, pero con funcionalidades sencillas e inteligentes para construir cualquier sitio que se te pase por la cabeza.
+ +Uno no sustituye al otro. Merece la pena experimentarlos y ver sus diferentes enfoques.
+ +Comunidad
+ +La comunidad de Python es una de las más sanas y activas que te podrás encontrar. Los usuarios organizan espontáneamente charlas mensuales y talleres gratuitos en torno al lenguaje. Anualmente se celebra diversos congresos. El más popular se conoce como PyCon y este año en España se celebra la 6ª edición en Málaga entre el 5 y 7 de Octubre. Pero también hay grupos especiales como las Django Girls, un grupo femenino para animar a que otras mujeres den el paso de aprender a programar.
+ +Su gran apoyo por la comunidad se debe en parte por la gran variedad de profesiones que usan Python, como puede ser: el análisis de datos, la inteligencia artificial, la creación de aplicaciones para escritorio, desarrollo de micro dispositivos, etc… Las librerías no dejan de crecer y suelen estar cuidadosamente documentadas, promoviendo un entorno agradable.
+ +Competidores
+ +En cuanto a la competencia, es amplia y con mucha experiencia. Hecho que no es malo de por sí. Los más destacables son: PHP, Ruby, Node.js, Java y Go. Aunque Ruby podría considerarse un primo hermano por sus similitudes. Ambos se encuentras muy equilibrados, aunque Python no deja de subir año tras año entre los lenguajes más utilizados.
+ +Recomendaciones para el primerizo
+ +Si quieres iniciarte en este lenguaje interpretado, y en concreto en el universo Web, te aconsejo que le des una oportunidad a Flask. Puedes crear pequeños proyectos como una web sencilla, un REST API o un panel administrativo. Poco después sería aconsejable dar el salto a Django, y vivir en tus propias carnes una de las experiencias más completas de Python. Sumérgete en proyectos con una gran densidad de trabajo, como puede ser un blog, un e-commerce o una red social. Descubre cada uno de sus detalles, visita los ejemplos de la documentación, diseña bases de datos relacionales de gran solidez… no te decepcionará el ORM de Django (gestor para realizar consultas en la base de datos) ni su motor de plantillas.
+ +Futuro
+ +Las previsiones son muy buenas. Las versiones son constantes y compatibles con todas las plataforma. Su creador, Guido van Rossum, es denominado como “Benevolente dictador vitalicio” por dejar que la comunidad tomen las decisiones. Tan solo dejó 4 directrices:
+ +-
+
- Python debería ser fácil, intuitivo y tan potente como sus principales competidores. +
- El proyecto sería de Código Abierto para que cualquiera pudiera colaborar. +
- El código escrito en Python sería tan comprensible como cualquier texto en inglés. +
- Python debería ser apto para las actividades diarias permitiendo la construcción de prototipos en poco tiempo. +
Y por ahora la comunidad lo cumple todo.
+ +Ahora ya conoces los riesgos y beneficios, ¿te atreves a cruzar la frontera?
+
+
+ La libertad de desarrollar...: Contar palabras de un texto usando Spark con PySpark
+Python Hispano 03 07 2018
+En el artículo anterior se explicó el procedimiento de instalación de Spark usando Docker. En este artículo se usará un texto tomado de la página de la ONU, de ahí se extrae las líneas y se cuentan las palabras.
A continuación el texto que se va a utilizar (lo pueden bajar desde el repositorio gitlab):
1942: La Declaración de las Naciones Unidas
Representantes de 26 Estados que lucharon contra las potencias del Eje Roma-Berlín-Tokio manifestaron su apoyo a la Carta del Atlántico mediante su firma de la « Declaración de las Naciones Unidas ». En este trascendental documento, los signatarios se comprometían a poner su máximo empeño en la guerra y a no firmar una paz por separado.
Declaración de las Naciones Unidas prometiendo "emplear todos sus recursos, militares o económicos" en "la lucha por la victoria sobre el hitlerismo".
El día de año nuevo de 1942, el señor presidente Roosevelt y los señores Winston Churchill, Maxim Litvinov, de la Unión Soviética, y T. V. Soong, de China, firmaron un breve documento que luego se conocería como la Declaración de las Naciones Unidas. Al día siguiente se sumaron los representantes de otras 22 naciones más. En este trascendental documento, los signatarios se comprometían a poner su máximo empeño en la guerra y a no firmar una paz por separado.
La Declaración de las Naciones Unidas
La alianza completa a que se llegó en esta forma concordaba con los principios enunciados en la Carta del Atlántico, y la primera cláusula de la declaración de las Naciones Unidas reza que los países signatarios
« . . . han suscrito un programa común de propósitos y principios enunciados en la declaración conjunta del presidente de los Estados Unidos de América y del primer ministro del Reino Unido de la Gran Bretaña e Irlanda del Norte, fechada el 14 de agosto de 1941, y conocida como la Carta del Atlántico. ».
Cuando tres años después se iniciaban los preparativos para la conferencia de San Francisco, únicamente se invitó a participar a aquellos estados que, en marzo de 1945, habían declarado la guerra a Alemania y al Japón y que habían firmado la Declaración de las Naciones Unidas.
Signatarios Originales de la Declaración de la ONU
Los 26 signatarios originales fueron: Los Estados Unidos de América, el Reino Unido de la Gran Bretaña e Irlanda del Norte, la Unión de Repúblicas Socialistas Soviéticas, China, Australia, Bélgica, Canadá, Costa Rica, Checoeslovaquia, El Salvador, Grecia, Guatemala, Haití, Honduras, India, Luxemburgo, Nicaragua, Noruega, Nueva Zelandia, Países Bajos, Panamá, Polonia, República Dominicana, Unión Sudafricana, Yugoeslavia .
Los firmantes posteriores
Más tarde se adhirieron a la Declaración los siguientes países (en el orden de las firmas): México, Colombia, Iraq, Irán, Liberia, Paraguay, Chile, Uruguay, Egipto, Siria, Francia, Filipinas, Brasil, Bolivia, Etiopía, Ecuador, Perú, Venezuela, Turquía, Arabia Saudita, Líbano.
A continuación se muestra la ejecución del código (si quieren bajar el archivo jupyter notebook lo pueden descargar desde gitlab):
In [1]:
#Se importa SparkContext y SparkConf
from pyspark import SparkContext, SparkConf
In [2]:
#Se crea la instancia de la configuración con el nombre de la aplicación contador
conf1 = SparkConf().setAppName("contador").setMaster("local[3]")
In [3]:
#Se crea el contexto pasando la instancia de la configuración
sc = SparkContext(conf = conf1)
In [4]:
#Se extrae las líneas del texto
lineas = sc.textFile("data/declaracion_onut.text")
In [6]:
#Se extrae las palabras del texto y se cuentan
contarPalabras = lineas.flatMap(lambda linea: linea.split(" ")).countByValue()
In [7]:
#Se muestra las palabras con la cantidad de veces que tiene su aparición
for palabra, contador in contarPalabras.items():
print("{} : {}".format(palabra, contador))
Como se puede ver, se logra obtener la cantidad de veces que aparecen las palabras en el texto. +
+ 
+
+
+ Unfinished Work
+MonkeyUser 03 07 2018
+
+
+ These Months in Common Lisp: Q2 2018
+Lisp journey 02 07 2018
+Documentation
+ +-
+
- Paradigms of Artificial Intelligence Programming epub +
- Models and Databases, with Mito and SxQL - the Common Lisp Cookbook +
- Awesome Common Lisp learning list +
Announcements
+ +-
+
- ELS2018 proceedings (PDF) +
- SBCL 1.4.6 released +
- SBCL 1.4.7 Released +
- LispWorks 7.1.1 - Patches +
- SBCL method-combination fixes +
- SBCL method tracing +
- $500 Bounty on Clozure/ccl +
Jobs
+ +-
+
- Junior Lisp Developer, RavenPack, Marbella, Spain +
- 3E : Lisp Developer - development, maintenance, design and unit testing of SynaptiQ’s real-time aggregation and alerting engine that processes time-series and events. This data engine is Common Lisp based. +
- Lisp Engineer - AI (Natural Language Reasoning) +
Projects
+ +Quicklisp dist update, march 2018
+ +-
+
- SHCL: An Unholy Union of POSIX Shell and Common Lisp (reddit) +
- cl-notebook +
- Heroku buildpack for Common Lisp +
- Kubernetes Client Library for Common Lisp +
- Interactive Common Lisp code snippets in any web page +
- rove - small testing framework (Fukamachi’s successor to Prove) +
- can - a role-based access right control library +
- house - custom asynchronous HTTP server for the Deal project. +
- oxenfurt - A Common Lisp client library for the Oxford dictionary API. +
- algebraic-data-library +
- Lisp Interface to Federal Reserve Economic Data (FRED®) +
- reddit1.0 source code (comments), then Reddit’s code runs on SBCL. See also reddit. +
- Petalisp: Elegant High Performance Computing +
- Code Golf Site with Common Lisp Support! +
- vseloved/wiki-lang-detect: Text language identification using Wikipedia data +
- ppath, a path manipulation library +
- CRAM: Cognitive Robot Abstract Machine - a toolbox for designing, implementing and deploying software on autonomous robots +
- cl-statistics.lisp +
- Pseudoscheme - An implementation of Scheme embedded in Common Lisp (“with minor changes it runs in ABCL, CCL, ECL and LispWorks. But not in SBCL…”) +
- Powerlisp: A simple tool to automate your work with dmenu/rofi +
- curry-compose-reader-macros - concise function partial application and composition +
- json-mop: A metaclass for bridging CLOS and JSON objects +
- clsh: a set of Lispy bindings for running and composing *nix processes +
- snakes - Python style generators for Common Lisp. (Includes a port of itertools.) +
new releases:
+ + + +(re)discoveries:
+ +-
+
- Cocoa interface code written in Lisp for use with Clozure Common Lisp +
- cl-bench - Common Lisp benchmarking suite +
- Eclipse Common Lisp (Howard Stearns / Elwood Corp) +
- Arboreta/arboreta-wasm - Common Lisp tooling for WebAssembly +
- QGAME: Quantum and Gate Measurement Emulator +
- Trivia: Pattern Matching +
From the Lisp Game Jam 2018:
+ + + +all results
+ +Articles
+ +-
+
- Lisp, Jazz, Aikido: Three Expressions of a Single Essence +
- Creating a CL-Rivescript Interpreter (Part 1) and part 10 +
- Why lisp - biolisp +
- Scripting in Common Lisp with buildapp’s multi-call binaries and fare’s cl-scripting +
- Fun with Macros: Gathering / Steve Losh +
- Calling Go Functions from Lisp +
- Lispology - Printing floating-point numbers +
- Prolog to Lisp +
- How do you design with Prolog in Lisp? +
- When to use type specifiers in CL code? +
- Jeff Massung: Common Lisp libraries that I made over the course of a few years and have consistenly returned to, always found useful, and kept up-to-date. +
- Experience writing a full featured livejournal blog client in Common Lisp. Part 2: client logic +
- My Lisp Journey #1: Getting Started With trivial-gamekit +
- The (Un)common Lisp approach to Operations Research (2012) +
- Alien: Return of Alien Technology to Classical Planning +
Discussion
+ +-
+
- What Common Lisp web library should I use?, and Lisp for building a web app, options? +
- How to collect all asdf dependencies for package-inferred-system? +
- SBCL on Raspberry Pi +
- Please, join the cl-telegram-bot refactoring effort! +
- GUI development done in Lisp (2013 comment) (reddit) +
- Question: trying to generalize posix ‘stat-’ functions +
- Package Name and Nickname Collisions in Quicklisp +
- Common Lisp and Machine Learning these days +
- Is cl-autowrap the preferred way to generate FFI bindings these days? +
- Want to make it so Common Lisp understands GeoJSON data +
- How to send and receive data over UDP asynchronously in common lisp? +
- Fun with Macros: Gathering / Steve Losh +
Learning Lisp:
+ +-
+
- One package per (or file project something-else)? +
- Small executables in LISP ? +
- What can Sly do out-of-the-metaphorical-box that slime+slime-company+
can’t?
+ - TIL that I can create CLOS constructors for conditions +
- Macro question from a Clojure programmer +
- Why did you decide to learn Lisp? +
- How do you go about starting a Common Lisp Project? A beginner looking for pointers. +
Screencasts
+ +-
+
- Lots of bits of lisp - CFFI +
- Lots of bits of Lisp - Macros (2 hr episode) +
- MIT OpenCourseWare +
- Lisp, The Quantum Programmer’s Choice - Computerphile episode 2 +
- McCLIM + Maxima: plot manipulation +
- McCLIM + Maxima: vector demo +
- Comfy Lisp Programming - Project “Wikify” | Episode 2 @ 10am PST +
- Pushing Pixels with Lisp - Episode 45 - World space shenanigans & Vignette +
- Common lisp and C++17 Live coding stream | TinyCDN CFFI Interop | Episode 13 +
- Growing a Lisp compiler - Amsterdam Lisp +
- Web Development in Emacs, Common Lisp and Clojurescript - Potato (Slack-like) +
- Any news on the ELS videos? (answer: no) +
Common Lisp VS …
+ + + +
+
+
+
+ New Weblocks tutorial: widgets
+Lisp journey 25 06 2018
+Weblocks is a web framework, created circa 2007, that allows to +write dynamic web applications in full Lisp, without a line of +Javascript. It is based on so called widgets, that are rendered +server-side and updated on the client, and it was also based on +continuations (they were removed in this fork, at least for now). It +was quietly being forgotten but it is being fixed, refactored, +documented and simplified by Alexander “svetlyak40wt” since a year or +so.
+ +I rewrote the quickstart to show the use of widgets, the heart of +Weblocks, Alexander proof-read and here we are:
+ +http://40ants.com/weblocks/quickstart.html (and reddit comments)
+ +I copy it below, of course check the official website for updates.
+ +The old Weblocks website is at https://common-lisp.net/project/cl-weblocks/
+ ++ +
Btw, other isomorphic web frameworks I know are Haskell’s +Haste, Nim’s +Karax, Ocaml’s +Heliom, Python’s +Nagare, of course Smalltalk’s +Seaside and +a couple more.
+ +Weblocks is now the easiest to get started with, the one “really +isomorphic” (bluring the line between server and client code), the +most elegant (to me) and one of the two, with Seaside, that allow for +REPL-driven development.
+ +For what I tested, Heliom is a hell to install, it seems a hell to +deploy, and it is bloated with specific Ocaml syntax that is always +upcoming in new compiler versions.
+ +Karax seems promising, it was recently used to rewrite the +Nim forum. It has currently zero docs +(not even a quickstart ;) ) and Nim’s ecosystem isn’t near as large as +CL’s. (and, well, no REPL, no Lisp)
+ +Nagare is actually based on Stackless Python. Looking at the code of +the successfull Kansha Trello clone, it +actually includes inline Javascript. And personnally, I’m running away from Python so…
+ ++ +
Quickstart
+ +++ +warning
+ ++
+ +- This version of Weblocks is not in Quicklisp yet. To
+- install it you need to clone the repository somewhere where ASDF +will find it, for example, to the
+~/common-lisp/directory.Load weblocks and create a package for a sandbox:
+
CL-USER> (ql:quickload '(:weblocks :weblocks-ui :find-port))
+CL-USER> (defpackage todo
+ (:use #:cl
+ #:weblocks-ui/form
+ #:weblocks/html)
+ (:import-from #:weblocks/widget
+ #:render
+ #:update
+ #:defwidget)
+ (:import-from #:weblocks/actions
+ #:make-js-action)
+ (:import-from #:weblocks/app
+ #:defapp))
+#<PACKAGE "TODO">
+CL-USER> (in-package todo)
+#<PACKAGE "TODO">
+Now, create an application:
+ +TODO> (defapp tasks)
+TODO> (weblocks/debug:on)
+TODO> (defvar *port* (find-port:find-port))
+TODO> (weblocks/server:start :port *port*)
+ <INFO> [19:41:00] weblocks/server server.lisp (start) -
+ Starting weblocks WEBLOCKS/SERVER::PORT: 40000
+ WEBLOCKS/SERVER::SERVER-TYPE: :HUNCHENTOOT DEBUG: T
+ <INFO> [19:41:00] weblocks/server server.lisp (start-server) -
+ Starting webserver on WEBLOCKS/SERVER::INTERFACE: "localhost"
+ WEBLOCKS/SERVER::PORT: 40000 DEBUG: T
+ #<SERVER port=40000 running>
+ (NIL)
+Open http://localhost:40000/tasks/ in your browser (double check the +port) and you’ll see a text like that:
+ +No weblocks/session:init method defined.
+Please define a method weblocks.session:init to initialize a session.
+
+It could be something simple, like this one:
+
+(defmethod weblocks/session:init ((app tasks))
+ "Hello world!")
+
+Read more in the documentaion.
+It means that you didn’t write any code for your application. Let’s do +it now and make an application which outputs a list of tasks.
+ +In the end, we’ll build the mandatory TODO-list app:
+ +
The Task widget
+ +TODO> (defwidget task ()
+ ((title
+ :initarg :title
+ :accessor title)
+ (done
+ :initarg :done
+ :initform nil
+ :accessor done)))
+This code defines a task widget, the building block of our application.
+defwidget is similar to Common Lisp’s defclass, in fact it is only a
+wrapper around it. It takes a name, a list of super-classes (here ())
+and a list of slot definitions.
We can create a task with make-instance:
TODO> (defvar *task-1* (make-instance 'task :title "Make my first Weblocks app"))
+TODO> *task-1*
+#<TASK {1005406F33}>
+Above, :title is the initarg, and since we didn’t give a :done
+argument, it will be instanciated to its :initform, which is nil.
We defined accessors for both slots, so we can read and set them easily:
+ +TODO> (title *task-1*)
+"Make my first Weblocks app"
+TODO> (done *TASK-1*)
+NIL
+TODO> (setf (done *TASK-1*) t)
+T
+We define a constructor for our task:
+ +TODO> (defun make-task (&key title done)
+ (make-instance 'task :title title :done done))
+It isn’t mandatory, but it is good practice to do so.
+ +If you are not familiar with the Common Lisp Object System (CLOS), you +can have a look at Practical Common +Lisp +and the Common Lisp +Cookbook.
+ +Now let’s carry on with our application.
+ +The Tasks-list widget
+ +Below we define a more general widget that contains a list of tasks, and
+we tell Weblocks how to display them by specializing the render
+method for our newly defined classes:
TODO> (defwidget task-list ()
+ ((tasks
+ :initarg :tasks
+ :accessor tasks)))
+
+TODO> (defmethod render ((task task))
+ "Render a task."
+ (with-html
+ (:span (if (done task)
+ (with-html
+ (:s (title task)))
+ (title task)))))
+
+TODO> (defmethod render ((widget task-list))
+ "Render a list of tasks."
+ (with-html
+ (:h1 "Tasks")
+ (:ul
+ (loop for task in (tasks widget) do
+ (:li (render task))))))
+The with-html macro uses
+Spinneret under the hood,
+but you can use anything that outputs html.
We can check how the generated html looks like by calling render in
+the REPL:
TODO> (render *task-1*)
+<div class="widget task"><span>Make my first Weblocks app</span>
+</div>
+NIL
+But we still don’t get anything in the browser.
+ +TODO> (defun make-task-list (&rest rest)
+ "Create some tasks from titles."
+ (loop for title in rest collect
+ (make-task :title title)))
+
+TODO> (defmethod weblocks/session:init ((app tasks))
+ (declare (ignorable app))
+ (let ((tasks (make-task-list "Make my first Weblocks app"
+ "Deploy it somewhere"
+ "Have a profit")))
+ (make-instance 'task-list :tasks tasks)))
+This defines a list of tasks (for simplicity, they are defined as a list +in memory) and returns what will be our session’s root widget..
+ +Restart the application:
+ +TODO> (weblocks/debug:reset-latest-session)
+Right now it should look like this:
+ +
Adding tasks
+ +Now, we’ll add some ability to interact with a list – to add some tasks +into it, like so:
+ +
Import a new module, weblocks-ui to help in creating forms and other
+UI elements:
TODO> (ql:quickload "weblocks-ui")
+TODO> (use-package :weblocks-ui/form)
+Write a new add-task function and modify the render method of a
+task-list:
TODO> (defmethod render ((widget task-list))
+ (flet ((add-task (&key title &allow-other-keys)
+ (push (make-task :title title)
+ (tasks (weblocks/widgets/root:get)))
+ (update (weblocks/widgets/root:get))))
+ (with-html
+ (:h1 "Tasks")
+ (loop for task in (tasks widget) do
+ (render task))
+ (with-html-form (:POST #'add-task)
+ (:input :type "text"
+ :name "title"
+ :placeholder "Task's title")
+ (:input :type "submit"
+ :value "Add")))))
+
+TODO> (weblocks/debug:reset-latest-session)
+The function add-task does only two simple things:
-
+
- it adds a task into a list; +
- it tells Weblocks that our root widget should be redrawn. +
This second point is really important because it allows Weblocks to
+render necessary parts of the page on the server and to inject it into
+the HTML DOM in the browser. Here it rerenders the root widget, but we
+can as well update a specific task widget, as we’ll do soon.
We also took care of defining add-task inline, as a closure, for it to
+be thread safe.
Another block in our new version of render of a task-list is the form:
(with-html-form (:POST #'add-task)
+ (:input :type "text"
+ :name "task"
+ :placeholder "Task's title")
+ (:input :type "submit"
+ :value "Add"))
+It defines a text field, a submit button and an action to perform on
+form submit. The add-task function will receive the text input as
+argument.
++ +note
+ +This is really amazing!
+ +With Weblocks, you can handle all the business logic server-side, +because an action can be any lisp function, even an anonymous lambda, +closuring all necessary variables.
+
Restart the application and reload the page. Test your form now and see +in a +Webinspector +how Weblocks sends requests to the server and receives HTML code with +rendered HTML block.
+ +Now we’ll make our application really useful – we’ll add code to toggle +the tasks’ status.
+ +Toggle tasks
+ +TODO> (defmethod toggle ((task task))
+ (setf (done task)
+ (if (done task)
+ nil
+ t))
+ (update task))
+
+TODO> (defmethod render ((task task))
+ (with-html
+ (:p (:input :type "checkbox"
+ :checked (done task)
+ :onclick (make-js-action
+ (lambda (&rest rest)
+ (declare (ignore rest))
+ (toggle task))))
+ (:span (if (done task)
+ (with-html
+ ;; strike
+ (:s (title task)))
+ (title task))))))
+We defined a small helper to toggle the done attribute, and we’ve
+modified our task rendering function by adding a code to render a
+checkbox with an anonymous lisp function, attached to its onclick
+attribute.
The function make-js-action returns a Javascript code, which calls
+back a lisp lambda function when evaluated in the browser. And because
+toggle updates a Task widget, Weblocks returns on this callback a new
+prerendered HTML for this one task only.
What is next?
+ +As a homework:
+ +-
+
- Play with lambdas and add a “Delete” button next after each task. +
- Add the ability to sort tasks by name or by completion flag. +
- Save tasks in a database (the +Cookbook +might help). +
- Read the rest of the documentation and make a real application, +using the full power of Common Lisp. +
+
+ Learning Rust 01: a pwd clone
+Posts on James Routley 23 06 2018
+
+ 
+
+
+ La libertad de desarrollar...: Visualización de Árbol de decisión
+Python Hispano 19 06 2018
+Como en Noviembre del año pasado, escribí un artículo sobre árboles de decisión con Python, donde se tenía una serie de datos de entrada (altura, peso y talla) y de salida si era hombre o mujer. Para este artículo lo que se va a agregar es la visualización del árbol de decisión, para ello se usará dos librerías de Python pydot y graphviz .
Se da por sentado que ya se tiene instalado scikit-learn, se instala entonces pydot y graphviz:
#pip3 install pydot
#pip3 install graphviz
Ahora se muestra el código:
Ahora toca la visualización del árbol:
Para terminar se muestra el grafo del árbol:
Este grafo se genera a partir de la instancia de la clase que se usa para ingresar los datos, se entrena, y se usa para predecir con nuevos datos.
La información que muestra cada nodo de decisión:
- Samples: La cantidad de muestras que se maneja.
- gini: Es un indice que indica el costo de la evaluación de separar los datos.
- value: Es un valor que se está evaluando en ese momento.
En próximo artículo se hará otro ejemplo ya con un mayor conjunto de datos.
Sí tienes algun pregunta u observación, puedes hacerlo en los comentarios del post.
¡Haz tu donativo!
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+
+ 
+
+
+ Happy Flow
+MonkeyUser 19 06 2018
+
+ 
+
+
+ TBD
+MonkeyUser 19 06 2018
+
+
+ How to use React (and Redux) with your crufty old CMS
+James Sinclair 13 06 2018
+
+
+ How to use React (and Redux) with your crufty old CMS
+Web Development - James Sinclair 13 06 2018
+
+ 
+
+
+ Root Cause
+MonkeyUser 12 06 2018
+
+ 
+
+
+ La libertad de desarrollar...: Análisis de Sentimiento de tweets con Python, TextBlob y tweepy
+Python Hispano 10 06 2018
+Existe el área de análisis de redes sociales, puedes hacer gráficos de tendencias, lograr cual fue el origen de un tweet. La idea es usar la librería tweepy para conectase a Twitter y de allí capturar los tweets para luego realizar un análisis de sentimiento y graficar el resultado.
El análisis de sentimiento se refiere al uso de procesamiento de lenguaje natural, análisis de texto y lingüistica computacional para identificar y extraer información subjetiva de los recursos (más información en wikipedia).
Se puede realizar análisis de sentimiento a cualquier texto, puede ser de correos, de páginas web, de publicaciones en redes sociales como twitter, facebook, google+, entre otros. Con ello se puede lograr un aproximado de la evaluación emocional que tiene un tema o persona en algún momento en las redes sociales o contenidos evaluados.
La idea es obtener el tráfico de twitter sobre un tema o persona, aplicarle análisis de sentimiento y graficar los resultados.
Este artículo se basa en un artículo en inglés publicado en freecodecamp con título Basic data analysis on Twitter with Python . Este artículo se desarrolla una aplicación gráfica en TK para obtener la información y luego realizar la captura, cálculos y gráficos. El código fuente de la aplicación del artículo se encuentra en github.
Para tener acceso al API de twitter se tiene que crear una cuenta en la página para las aplicaciones que lo requieran.
Para autenticarse se usará el siguiente código:
consumer_key = 'consumer key'
consumer_secret = 'consumer secrets'
access_token = 'access token'
access_token_secret = 'access token secret'
auth = tweepy.OAuthHandler(consumer_key, consumer_secret)
auth.set_access_token(access_token, access_token_secret)
api = tweepy.API(auth)
En este caso se usará jupyer lab para mostrar la aplicación con ajustes en el código para su reutilización, por ejemplo, que realice el análisis en Español o Inglés.
La librería a usar será tweepy, la librería para análisis de texto TextBlob y matplotlib.
Para instalar tweepy se usará pip3:
pip3 install tweepy textblob
Revisemos primero las tendencias en twitter para Valencia (Venezuela), a continuación una imagen de las tendencias.
Se buscará el análisis de sentimiento de la tendencia Rafael Nadal, se buscará en 200 tweets y en español.
A continuación el código fuente:
El código fuente en el repositorio de gitlab lo pueden ver en el enlace.
#!/usr/bin/env python3
#Se importa la librería tweepy
import tweepy
#Se importa sleep, datetime, TextBlob y matplotlib
from time import sleep
from datetime import datetime
from textblob import TextBlob
import matplotlib.pyplot as plt
#Se define las variables para el acceso al API de twitter
consumer_key = ''
consumer_secret = ''
access_token = ''
access_token_secret = ''
#Se autentica en twitter
auth = tweepy.OAuthHandler(consumer_key, consumer_secret)
auth.set_access_token(access_token, access_token_secret)
api = tweepy.API(auth)
#se verifica que el usuario conectado en twitter es de uno
print(api.me().name)
#Se pregunta por la palabra a preguntar
palabra = input("Buscar: ")
#Se define la cantida de tweets a capturar
numero_de_Tweets = int(input(u"Número de tweets a capturar: "))
#Se define el idioma de los tweets a analizar
lenguaje = input("Idioma [es/en]:")
def ObtenerTweets(palabra="Trump",times=100,leguanje="en"):
#Se define las listas que capturan la popularidad
popularidad_list = []
numeros_list = []
numero = 1
for tweet in tweepy.Cursor(api.search, palabra, lang=lenguaje).items(numero_de_Tweets):
try:
#Se toma el texto, se hace el analisis de sentimiento
#y se agrega el resultado a las listas
analisis = TextBlob(tweet.text)
analisis = analisis.sentiment
popularidad = analisis.polarity
popularidad_list.append(popularidad)
numeros_list.append(numero)
numero = numero + 1
except tweepy.TweepError as e:
print(e.reason)
except StopIteration:
break
return (numeros_list,popularidad_list,numero)
def GraficarDatos(numeros_list,popularidad_list,numero):
axes = plt.gca()
axes.set_ylim([-1, 2])
plt.scatter(numeros_list, popularidad_list)
popularidadPromedio = (sum(popularidad_list))/(len(popularidad_list))
popularidadPromedio = "{0:.0f}%".format(popularidadPromedio * 100)
time = datetime.now().strftime("A : %H:%M\n El: %m-%d-%y")
plt.text(0, 1.25,
"Sentimiento promedio: " + str(popularidadPromedio) + "\n" + time,
fontsize=12,
bbox = dict(facecolor='none',
edgecolor='black',
boxstyle='square, pad = 1'))
plt.title("Sentimientos sobre " + palabra + " en twitter")
plt.xlabel("Numero de tweets")
plt.ylabel("Sentimiento")
plt.show()
numeros_list,popularidad_list,numero = ObtenerTweets(palabra,numero_de_Tweets,lenguaje)
GraficarDatos(numeros_list,popularidad_list,numero)
Al ejecutar el programa se tiene la siguiente gráfica.
Para el caso de Nadal, tiene un valor promedio positivo, habrá casos donde el sentimiento sea de un valor negativo, pero para este caso, lo mejor es ampliar la cantidad de tweets a capturar para tener una mejor aproximación del sentimiento de la gente de lo que habla en twitter de Nadal.
Sí tienes algun pregunta u observación, puedes hacerlo en los comentarios del post.
¡Haz tu donativo!
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Para el caso de paypal, tienes el botón del lado derecho de la página.
+ 
+
+
+ La libertad de desarrollar...: Visualizando series de tiempo de precios del mercado con pandas y matplotlib
+Python Hispano 10 06 2018
+En este artículo la fuente de datos se usará la librería de Quandl directamente. La idea es obtener los precios de mercado de 3 Aerolineas (Delta con código DAL, Jet Blue con código JBLU y Southwest con código LUV). Se gráfica el historico de los precios de cierre, el volumen de ventas y movimientos promedios de estas tres aerolineas.
Continuando con los artículos sobre Pandas y Ciencia de Datos, en el artículo anterior se mostró como trabajar con Series de tiempo obteniendo datos desde Quandl.
Este artículo se basa en un artículo en inglés que se títula Visualizing Time Series Data of Stock Prices (en este artículo usan la librería pandas_datareader, pero está dando errores, así que se usará la librería Quandl).
El código del ejercicio se muestra a continuación:
Visualizando
Se va a graficar el Ajuste de precio de cierre de las 3 aerolineas.
Graficar el Volumen (Volume)
Se puede notar que la aerolinea Delta tiene un pico muy alto en algún momento del año 2013.
Para obtener la fecha se usa el método idxmax.
Los movimientos promedios se usan para detectar oportunidades de trading.
Este cálculo se toma de la media o promedio de los pasados precios (se llama movimientos promedio por que los datos están continuamente moviendose).
Dependiendo del tipo de inversor (alto riesgo vs bajo riesgo, corto término vs largo término), se pueden ajustar los movimientos promedio a 10 días, 20 días, 50 días, 200 días, 1 año, 5 años, etc.
Para este caso se calculará el movimiento promedio a 50 días y a 200 días.
Este cálculo se toma de la media o promedio de los pasados precios (se llama movimientos promedio por que los datos están continuamente moviendose).
Dependiendo del tipo de inversor (alto riesgo vs bajo riesgo, corto término vs largo término), se pueden ajustar los movimientos promedio a 10 días, 20 días, 50 días, 200 días, 1 año, 5 años, etc.
Para este caso se calculará el movimiento promedio a 50 días y a 200 días.
El raw del notebook lo pueden bajar del repositorio gitlab.
Si tienes alguna sugerencia o idea de como se puede aplicar este artículo, lo puedes dejar en los comentarios.
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+
+
+
+
+ June Update - Do you consent?
+WhoTracksMe blog 06 06 2018
+
+ 
+
+
+ Refactoring
+MonkeyUser 05 06 2018
+
+
+ Automating the Boring Stuff in Django Using the Check Framework
+Haki Benita 04 06 2018
+Every team has a unique development style. Some teams implement localization and require translations. Some teams are more sensitive to database issues and require more careful handling of indexes and constraints. In this article we describe how we enforce our own development style using the Django check framework, the inspect and the ast modules from the Python standard library.
+
+
+ The Power of Recursive Macros in Vim
+Jovica Ilic 03 06 2018
+If for some crazy reason you’re not already a user of Vim, shutdown your computer and go think about your life choices. Joking aside, Vim is really a great editor. And if you didn’t know – Vim supports macros. Basics of macros in Vim Macros represent a simple concept which can be described as “record... Continue reading
+The post The Power of Recursive Macros in Vim appeared first on Jovica Ilic.
+ +
+
+ Models and databases with the Mito ORM and SxQL
+Lisp journey 29 05 2018
+Following is a tutorial on how to use the Mito ORM.
+ +As usual, this is best read on the Common Lisp Cookbook. It will be updated there.
+ +The +Database section on the Awesome-cl list +is a resource listing popular libraries to work with different kind of +databases. We can group them roughly in four categories:
+ +-
+
- wrappers to one database engine (cl-sqlite, postmodern, cl-redis,…), +
- interfaces to several DB engines (clsql, sxql,…), +
- persistent object databases (bknr.datastore (see chap. 21 of “Common Lisp Recipes”), ubiquitous,…), +
- Object Relational Mappers (Mito), +
and other DB-related tools (pgloader).
+ +We’ll begin with an overview of Mito. If you must work with an +existing DB, you might want to have a look at cl-dbi and clsql. If you +don’t need a SQL database and want automatic persistence of Lisp +objects, you also have a choice of libraries.
+ +The Mito ORM and SxQL
+ +Mito is in Quicklisp:
+ +(ql:quickload :mito)
+Overview
+ +Mito is “an ORM for Common Lisp +with migrations, relationships and PostgreSQL support”.
+ +-
+
- it supports MySQL, PostgreSQL and SQLite3, +
- when defining a model, it adds an
id(serial primary key), +created_atandupdated_atfields by default like Ruby’s +ActiveRecord or Django,
+ - handles DB migrations for the supported backends, +
- permits DB schema versioning, +
- is tested under SBCL and CCL. +
As an ORM, it allows to write class definitions, to specify +relationships, and provides functions to query the database. For +custom queries, it relies on +SxQL, an SQL generator that +provides the same interface for several backends.
+ +Working with Mito generally involves these steps:
+ +-
+
- connecting to the DB +
- writing CLOS classes to define models +
- running migrations to create or alter tables +
- creating objects, saving same in the DB, +
and iterating.
+ +Connecting to a DB
+ +Mito provides the function connect-toplevel to establish a
+connection to RDBMs:
(mito:connect-toplevel :mysql :database-name "myapp" :username "fukamachi" :password "c0mon-1isp")
+The driver type can be of :mysql, :sqlite3 and :postgres.
With sqlite you don’t need the username and password:
+ +(connect-toplevel :sqlite3 :database-name "myapp")
+As usual, you need to create the MySQL or Postgre database beforehand. +Refer to their documentation.
+ +Connecting sets mito:*connection* to the new connection and returns it.
Disconnect with disconnect-toplevel.
=> you might make good use of a wrapper function:
+ +(defun connect ()
+ "Connect to the DB."
+ (connect-toplevel :sqlite3 :database-name "myapp"))
+Models
+ +Defining models
+ +In Mito, you can define a class which corresponds to a database table
+by specifying (:metaclass mito:dao-table-class):
(defclass user ()
+ ((name :col-type (:varchar 64)
+ :initarg :name
+ :accessor user-name)
+ (email :col-type (or (:varchar 128) :null)
+ :initarg :email
+ :accessor user-email))
+ (:metaclass mito:dao-table-class))
+Note that the class automatically adds some slots: a primary key named id
+if there’s no primary keys, created_at and updated_at for
+recording timestamps. To disable these behaviors, specify :auto-pk
+nil or :record-timestamps nil to the defclass forms.
You can inspect the new class:
+ +(mito.class:table-column-slots (find-class 'user))
+;=> (#<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS MITO.DAO.MIXIN::ID>
+; #<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS COMMON-LISP-USER::NAME>
+; #<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS COMMON-LISP-USER::EMAIL>
+; #<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS MITO.DAO.MIXIN::CREATED-AT>
+; #<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS MITO.DAO.MIXIN::UPDATED-AT>)
+The class inherits mito:dao-class implicitly.
(find-class 'user)
+;=> #<MITO.DAO.TABLE:DAO-TABLE-CLASS COMMON-LISP-USER::USER>
+
+(c2mop:class-direct-superclasses *)
+;=> (#<STANDARD-CLASS MITO.DAO.TABLE:DAO-CLASS>)
+This may be useful when you define methods which can be applied for +all table classes.
+ +For more information on using the Common Lisp Object System, see the +clos page.
+ +Creating the tables
+ +After defining the models, you must create the tables:
+ +(mito:ensure-table-exists 'user)
+So a helper function:
+ +(defun ensure-tables ()
+ (mapcar #'mito:ensure-table-exists '(user foo bar)))
+See +Mito’s documentation +for a couple more ways.
+ +When you alter the model you’ll need to run a DB migration, see the next section.
+ +Fields
+ +Fields types
+ +Field types are:
+ +(:varchar <integer>) ,
:serial, :bigserial, :integer, :bigint, :unsigned,
:timestamp, :timestamptz,
:bytea,
Optional fields
+ +Use (or <real type> :null):
(email :col-type (or (:varchar 128) :null)
+ :initarg :email
+ :accessor user-email))
+Field constraints
+ +:unique-keys can be used like so:
(defclass user ()
+ ((name :col-type (:varchar 64)
+ :initarg :name
+ :accessor user-name)
+ (email :col-type (:varchar 128)
+ :initarg :email
+ :accessor user-email))
+ (:metaclass mito:dao-table-class)
+ (:unique-keys email))
+We already saw :primary-key.
You can change the table name with :table-name.
Relationships
+ +You can define a relationship by specifying a foreign class with :col-type:
(defclass tweet ()
+ ((status :col-type :text
+ :initarg :status
+ :accessor tweet-status)
+ ;; This slot refers to USER class
+ (user :col-type user
+ :initarg :user
+ :accessor tweet-user))
+ (:metaclass mito:dao-table-class))
+
+(table-definition (find-class 'tweet))
+;=> (#<SXQL-STATEMENT: CREATE TABLE tweet (
+; id BIGSERIAL NOT NULL PRIMARY KEY,
+; status TEXT NOT NULL,
+; user_id BIGINT NOT NULL,
+; created_at TIMESTAMP,
+; updated_at TIMESTAMP
+; )>)
+Now you can create or retrieve a TWEET by a USER object, not a USER-ID.
(defvar *user* (mito:create-dao 'user :name "Eitaro Fukamachi"))
+(mito:create-dao 'tweet :user *user*)
+
+(mito:find-dao 'tweet :user *user*)
+Mito doesn’t add foreign key constraints for refering tables.
+ +One-to-one
+ +A one-to-one relationship is simply represented with a simple foreign
+key on a slot (as :col-type user in the tweet class). Besides, we
+can add a unicity constraint, as with (:unique-keys email).
One-to-many, many-to-one
+ +The tweet example above shows a one-to-many relationship between a user and +his tweets: a user can write many tweets, and a tweet belongs to only +one user.
+ +The relationship is defined with a foreign key on the “many” side
+linking back to the “one” side. Here the tweet class defines a
+user foreign key, so a tweet can only have one user. You didn’t need
+to edit the user class.
A many-to-one relationship is actually the contraty of a one-to-many. +You have to put the foreign key on the approriate side.
+ +Many-to-many
+ +A many-to-many relationship needs an intermediate table, which will be +the “many” side for the two tables it is the intermediary of.
+ +And, thanks to the join table, we can store more information about the relationship.
+ +Let’s define a book class:
(defclass book ()
+ ((title
+ :col-type (:varchar 128)
+ :initarg :title
+ :accessor title)
+ (ean
+ :col-type (or (:varchar 128) :null)
+ :initarg :ean
+ :accessor ean))
+ (:metaclass mito:dao-table-class))
+A user can have many books, and a book (as the title, not the physical +copy) is likely to be in many people’s library. Here’s the +intermediate class:
+ +(defclass user-books ()
+ ((user
+ :col-type user
+ :initarg :user)
+ (book
+ :col-type book
+ :initarg :book))
+ (:metaclass mito:dao-table-class))
+Each time we want to add a book to a user’s collection (say in
+a add-book function), we create a new user-books object.
But someone may very well own many copies of one book. This is an +information we can store in the join table:
+ +(defclass user-books ()
+ ((user
+ :col-type user
+ :initarg :user)
+ (book
+ :col-type book
+ :initarg :book)
+ ;; Set the quantity, 1 by default:
+ (quantity
+ :col-type :integer
+ :initarg :quantity
+ :initform 1
+ :accessor quantity))
+ (:metaclass mito:dao-table-class))
+Inheritance and mixin
+ +A subclass of DAO-CLASS is allowed to be inherited. This may be useful +when you need classes which have similar columns:
+ +(defclass user ()
+ ((name :col-type (:varchar 64)
+ :initarg :name
+ :accessor user-name)
+ (email :col-type (:varchar 128)
+ :initarg :email
+ :accessor user-email))
+ (:metaclass mito:dao-table-class)
+ (:unique-keys email))
+
+(defclass temporary-user (user)
+ ((registered-at :col-type :timestamp
+ :initarg :registered-at
+ :accessor temporary-user-registered-at))
+ (:metaclass mito:dao-table-class))
+
+(mito:table-definition 'temporary-user)
+;=> (#<SXQL-STATEMENT: CREATE TABLE temporary_user (
+; id BIGSERIAL NOT NULL PRIMARY KEY,
+; name VARCHAR(64) NOT NULL,
+; email VARCHAR(128) NOT NULL,
+; registered_at TIMESTAMP NOT NULL,
+; created_at TIMESTAMP,
+; updated_at TIMESTAMP,
+; UNIQUE (email)
+; )>)
+If you need a ‘template’ for tables which doesn’t related to any
+database tables, you can use DAO-TABLE-MIXIN. Below the has-email
+class will not create a table.
(defclass has-email ()
+ ((email :col-type (:varchar 128)
+ :initarg :email
+ :accessor object-email))
+ (:metaclass mito:dao-table-mixin)
+ (:unique-keys email))
+;=> #<MITO.DAO.MIXIN:DAO-TABLE-MIXIN COMMON-LISP-USER::HAS-EMAIL>
+
+(defclass user (has-email)
+ ((name :col-type (:varchar 64)
+ :initarg :name
+ :accessor user-name))
+ (:metaclass mito:dao-table-class))
+;=> #<MITO.DAO.TABLE:DAO-TABLE-CLASS COMMON-LISP-USER::USER>
+
+(mito:table-definition 'user)
+;=> (#<SXQL-STATEMENT: CREATE TABLE user (
+; id BIGSERIAL NOT NULL PRIMARY KEY,
+; name VARCHAR(64) NOT NULL,
+; email VARCHAR(128) NOT NULL,
+; created_at TIMESTAMP,
+; updated_at TIMESTAMP,
+; UNIQUE (email)
+; )>)
+See more examples of use in mito-auth.
+ +Troubleshooting
+ +“Cannot CHANGE-CLASS objects into CLASS metaobjects.”
+ +If you get the following error message:
+ +Cannot CHANGE-CLASS objects into CLASS metaobjects.
+ [Condition of type SB-PCL::METAOBJECT-INITIALIZATION-VIOLATION]
+See also:
+ The Art of the Metaobject Protocol, CLASS [:initialization]
+it is certainly because you first wrote a class definition and then +added the Mito metaclass and tried to evaluate the class definition +again.
+ +If this happens, you must remove the class definition from the current package:
+ +(setf (find-class 'foo) nil)
+or, with the Slime inspector, click on the class and find the “remove” button.
+ +More info here.
+ +Migrations
+ +First create the tables if needed:
+ +(ensure-table-exists 'user)
+then alter the tables, if needed:
+ +(mito:migrate-table 'user)
+You can check the SQL generated code with migration-expressions
+'class. For example, we create the user table:
(ensure-table-exists 'user)
+;-> ;; CREATE TABLE IF NOT EXISTS "user" (
+; "id" BIGSERIAL NOT NULL PRIMARY KEY,
+; "name" VARCHAR(64) NOT NULL,
+; "email" VARCHAR(128),
+; "created_at" TIMESTAMP,
+; "updated_at" TIMESTAMP
+; ) () [0 rows] | MITO.DAO:ENSURE-TABLE-EXISTS
+There are no changes from the previous user definition:
+ +(mito:migration-expressions 'user)
+;=> NIL
+Now let’s add a unique email field:
(defclass user ()
+ ((name :col-type (:varchar 64)
+ :initarg :name
+ :accessor user-name)
+ (email :col-type (:varchar 128)
+ :initarg :email
+ :accessor user-email))
+ (:metaclass mito:dao-table-class)
+ (:unique-keys email))
+The migration will run the following code:
+ +(mito:migration-expressions 'user)
+;=> (#<SXQL-STATEMENT: ALTER TABLE user ALTER COLUMN email TYPE character varying(128), ALTER COLUMN email SET NOT NULL>
+; #<SXQL-STATEMENT: CREATE UNIQUE INDEX unique_user_email ON user (email)>)
+so let’s apply it:
+ +(mito:migrate-table 'user)
+;-> ;; ALTER TABLE "user" ALTER COLUMN "email" TYPE character varying(128), ALTER COLUMN "email" SET NOT NULL () [0 rows] | MITO.MIGRATION.TABLE:MIGRATE-TABLE
+; ;; CREATE UNIQUE INDEX "unique_user_email" ON "user" ("email") () [0 rows] | MITO.MIGRATION.TABLE:MIGRATE-TABLE
+;-> (#<SXQL-STATEMENT: ALTER TABLE user ALTER COLUMN email TYPE character varying(128), ALTER COLUMN email SET NOT NULL>
+; #<SXQL-STATEMENT: CREATE UNIQUE INDEX unique_user_email ON user (email)>)
+Queries
+ +Creating objects
+ +We can create user objects with the regular make-instance:
(defvar me
+ (make-instance 'user :name "Eitaro Fukamachi" :email "e.arrows@gmail.com"))
+;=> USER
+To save it in DB, use insert-dao:
(mito:insert-dao me)
+;-> ;; INSERT INTO `user` (`name`, `email`, `created_at`, `updated_at`) VALUES (?, ?, ?, ?) ("Eitaro Fukamachi", "e.arrows@gmail.com", "2016-02-04T19:55:16.365543Z", "2016-02-04T19:55:16.365543Z") [0 rows] | MITO.DAO:INSERT-DAO
+;=> #<USER {10053C4453}>
+Do the two steps above at once:
+ +(mito:create-dao 'user :name "Eitaro Fukamachi" :email "e.arrows@gmail.com")
+You should not export the user class and create objects outside of
+its package (it is good practice anyway to keep all database-related
+operations in say a models package and file). You should instead use
+a helper function:
(defun make-user (&key name)
+ (make-instance 'user :name name))
+Updating fields
+ +(setf (slot-value me 'name) "nitro_idiot")
+;=> "nitro_idiot"
+and save it:
+ +(mito:save-dao me)
+Deleting
+ +(mito:delete-dao me)
+;-> ;; DELETE FROM `user` WHERE (`id` = ?) (1) [0 rows] | MITO.DAO:DELETE-DAO
+
+;; or:
+(mito:delete-by-values 'user :id 1)
+;-> ;; DELETE FROM `user` WHERE (`id` = ?) (1) [0 rows] | MITO.DAO:DELETE-DAO
+Get the primary key value
+ +(mito:object-id me)
+;=> 1
+Count
+ +(mito:count-dao 'user)
+;=> 1
+Find one
+ +(mito:find-dao 'user :id 1)
+;-> ;; SELECT * FROM `user` WHERE (`id` = ?) LIMIT 1 (1) [1 row] | MITO.DB:RETRIEVE-BY-SQL
+;=> #<USER {10077C6073}>
+So here’s a possibility of generic helpers to find an object by a given key:
+ +(defgeneric find-user (key-name key-value)
+ (:documentation "Retrieves an user from the data base by one of the unique
+keys."))
+
+(defmethod find-user ((key-name (eql :id)) (key-value integer))
+ (mito:find-dao 'user key-value))
+
+(defmethod find-user ((key-name (eql :name)) (key-value string))
+ (first (mito:select-dao 'user
+ (sxql:where (:= :name key-value)))))
+Find all
+ +Use select-dao.
Get a list of all users:
+ +(mito:select-dao 'user)
+;=> (#<USER {10077C6073}>)
+Find by relationship
+ +As seen above:
+ +(mito:find-dao 'tweet :user *user*)
+Custom queries
+ +It is with select-dao that you can write more precise queries by
+giving it SxQL statements.
Example:
+ +(select-dao 'tweet
+ (where (:like :status "%Japan%")))
+Clauses
+ +See the SxQL documentation.
+ +Examples:
+ +(select-dao 'foo
+ (where (:and (:> :age 20) (:<= :age 65))))
+(order-by :age (:desc :id))
+(group-by :sex)
+(having (:>= (:sum :hoge) 88))
+(limit 0 10)
+and joins, etc.
Operators
+ +:not
+:is-null, :not-null
+:asc, :desc
+:distinct
+:=, :!=
+:<, :>, :<= :>=
+:a<, :a>
+:as
+:in, :not-in
+:like
+:and, :or
+:+, :-, :* :/ :%
+:raw
+Triggers
+ +Since insert-dao, update-dao and delete-dao are defined as generic
+functions, you can define :before, :after or :around methods to those, like regular method combination.
(defmethod mito:insert-dao :before ((object user))
+ (format t "~&Adding ~S...~%" (user-name object)))
+
+(mito:create-dao 'user :name "Eitaro Fukamachi" :email "e.arrows@gmail.com")
+;-> Adding "Eitaro Fukamachi"...
+; ;; INSERT INTO "user" ("name", "email", "created_at", "updated_at") VALUES (?, ?, ?, ?) ("Eitaro Fukamachi", "e.arrows@gmail.com", "2016-02-16 21:13:47", "2016-02-16 21:13:47") [0 rows] | MITO.DAO:INSERT-DAO
+;=> #<USER {100835FB33}>
+Inflation/Deflation
+ +Inflation/Deflation is a function to convert values between Mito and RDBMS.
+ +(defclass user-report ()
+ ((title :col-type (:varchar 100)
+ :initarg :title
+ :accessor report-title)
+ (body :col-type :text
+ :initarg :body
+ :initform ""
+ :accessor report-body)
+ (reported-at :col-type :timestamp
+ :initarg :reported-at
+ :initform (local-time:now)
+ :accessor report-reported-at
+ :inflate #'local-time:universal-to-timestamp
+ :deflate #'local-time:timestamp-to-universal))
+ (:metaclass mito:dao-table-class))
+Eager loading
+ +One of the pains in the neck to use ORMs is the “N+1 query” problem.
+ +;; BAD EXAMPLE
+
+(use-package '(:mito :sxql))
+
+(defvar *tweets-contain-japan*
+ (select-dao 'tweet
+ (where (:like :status "%Japan%"))))
+
+;; Getting names of tweeted users.
+(mapcar (lambda (tweet)
+ (user-name (tweet-user tweet)))
+ *tweets-contain-japan*)
+This example sends a query to retrieve a user like “SELECT * FROM user +WHERE id = ?” at each iteration.
+ +To prevent this performance issue, add includes to the above query
+which only sends a single WHERE IN query instead of N queries:
;; GOOD EXAMPLE with eager loading
+
+(use-package '(:mito :sxql))
+
+(defvar *tweets-contain-japan*
+ (select-dao 'tweet
+ (includes 'user)
+ (where (:like :status "%Japan%"))))
+;-> ;; SELECT * FROM `tweet` WHERE (`status` LIKE ?) ("%Japan%") [3 row] | MITO.DB:RETRIEVE-BY-SQL
+;-> ;; SELECT * FROM `user` WHERE (`id` IN (?, ?, ?)) (1, 3, 12) [3 row] | MITO.DB:RETRIEVE-BY-SQL
+;=> (#<TWEET {1003513EC3}> #<TWEET {1007BABEF3}> #<TWEET {1007BB9D63}>)
+
+;; No additional SQLs will be executed.
+(tweet-user (first *))
+;=> #<USER {100361E813}>
+Schema versioning
+ +$ ros install mito
+$ mito
+Usage: mito command [option...]
+
+Commands:
+ generate-migrations
+ migrate
+
+Options:
+ -t, --type DRIVER-TYPE DBI driver type (one of "mysql", "postgres" or "sqlite3")
+ -d, --database DATABASE-NAME Database name to use
+ -u, --username USERNAME Username for RDBMS
+ -p, --password PASSWORD Password for RDBMS
+ -s, --system SYSTEM ASDF system to load (several -s's allowed)
+ -D, --directory DIRECTORY Directory path to keep migration SQL files (default: "/Users/nitro_idiot/Programs/lib/mito/db/")
+ --dry-run List SQL expressions to migrate
+Introspection
+ +Mito provides some functions for introspection.
+ +We can access the information of columns with the functions in
+(mito.class.column:...):
-
+
table-column-[class, name, info, not-null-p,...]
+primary-key-p
+
and likewise for tables with (mito.class.table:...).
Given we get a list of slots of our class:
+ +(ql:quickload "closer-mop")
+
+(closer-mop:class-direct-slots (find-class 'user))
+;; (#<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS NAME>
+;; #<MITO.DAO.COLUMN:DAO-TABLE-COLUMN-CLASS EMAIL>)
+
+(defparameter user-slots *)
+We can answer the following questions:
+ +What is the type of this column ?
+ +(mito.class.column:table-column-type (first user-slots))
+;; (:VARCHAR 64)
+Is this column nullable ?
+ +(mito.class.column:table-column-not-null-p
+ (first user-slots))
+;; T
+(mito.class.column:table-column-not-null-p
+ (second user-slots))
+;; NIL
+Testing
+ +We don’t want to test DB operations against the production one. We +need to create a temporary DB before each test.
+ +The macro below creates a temporary DB with a random name, creates the +tables, runs the code and connects back to the original DB connection.
+ +(defun random-string (length)
+ ;; thanks 40ants/hacrm.
+ (let ((chars "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"))
+ (coerce (loop repeat length
+ collect (aref chars (random (length chars))))
+ 'string)))
+
+(defmacro with-empty-db (&body body)
+ "Run `body` with a new temporary DB.
+ "
+ `(let* ((*random-state* (make-random-state t))
+ (prefix (concatenate 'string
+ (random-string 8)
+ "/"))
+ (connection mito:*connection*))
+ (uiop:with-temporary-file (:pathname name :prefix prefix)
+ (let* ((*db-name* name)
+ (*db* (connect)))
+ (ensure-tables-exist)
+ (migrate-all)
+ ,@body
+ (setf mito:*connection* connection)
+ (connect)))))
+Use it like this:
+ +(prove:subtest "Creation in a temporary DB."
+ (with-empty-db
+ (let ((user (make-user :name "Cookbook")))
+ (save-user user)
+
+ (prove:is (name user)
+ "Cookbook"
+ "Test username in a temp DB."))))
+;; Creation in a temporary DB
+;; CREATE TABLE "user" (
+;; id BIGSERIAL NOT NULL PRIMARY KEY,
+;; name VARCHAR(64) NOT NULL,
+;; email VARCHAR(128) NOT NULL,
+;; created_at TIMESTAMP,
+;; updated_at TIMESTAMP,
+;; UNIQUE (email)
+;; ) () [0 rows] | MITO.DB:EXECUTE-SQL
+;; ✓ Test username in a temp DB.
+See also
+ +-
+
- mito-attachment +
- mito-auth +
- can a role-based access right control library +
- an advanced “defmodel” macro. +
+ 
+
+
+ Drive Test
+MonkeyUser 29 05 2018
+
+
+
+
+ Tracker Tax
+WhoTracksMe blog 28 05 2018
+
+
+ Dynamic Bézier Curves
+Josh Comeau's blog 23 05 2018
+
+ 
+
+
+ Reopened
+MonkeyUser 22 05 2018
+
+ 
+
+
+ Workaround
+MonkeyUser 15 05 2018
+
+ 
+
+
+ 10 comandos de terminal que quizás no conocías
+Emezeta blog 13 05 2018
+
+
+ May 2018 Monthly Update
+News on Clojurists Together 12 05 2018
+
+ 
+
+
+ Reviving Ana as Fathom: simple & transparent website analytics
+Danny van Kooten 11 05 2018
+++ +Update (Mar 2019): I left the Fathom project.
+
As I was browsing my Twitter feed a few weeks ago, I came across the following tweet.
+ +
I had the same idea in late 2016 when I set out to built my own open-source website analytics alternative called Ana. It even got some traction back then.
+ +Sadly, I got sidetracked and didn’t spend any more time on it. I still firmly believe in the idea though.
+ +Knowing Paul as a super knowledgeable power-user of our Mailchimp for WordPress plugin, I tweeted him that I would love to help out, if at all possible. And it was!
+ +Together, we are setting out to build website analytics that is simple, transparent and that respects your visitor’s privacy. We’re a few weeks in at this point and already running a beta version on our personal sites:
+ +
We’re developing Fathom out in the open; here’s Fathom on GitHub.
+ + +
+
+
+
+ May Update - Countdown to GDPR
+WhoTracksMe blog 10 05 2018
+
+ 
+
+
+ Code Reuse
+MonkeyUser 08 05 2018
+
+
+
+
+ Tutorial CSS: Cómo crear un objeto que baile
+Emezeta blog 04 05 2018
+
+
+
+
+ Tracking visits without tracking people
+WhoTracksMe blog 02 05 2018
+
+ 
+
+
+ Fixing Unit Tests
+MonkeyUser 02 05 2018
+
+
+ Q2 2018 Funding Announcement
+News on Clojurists Together 26 04 2018
+
+ 
+
+
+ Going Global
+MonkeyUser 24 04 2018
+
+
+
+
+ The end of google.{your country}?
+WhoTracksMe blog 22 04 2018
+
+
+ La libertad de desarrollar...: Algoritmo de Clasificación con scikit-learn
+Python Hispano 21 04 2018
+Continuando con los artículos sobre Inteligencia Artificial con Python.
La serie de artículos sobre Scikit-Learn han sido:
- Árbol de decisión hecho con Python (esté tendrá una segunda parte).
- Una red neuronal para aprendizaje supervisado usando scikit-learn.
- Funciones de activación para un perceptron.
Scikit-learn es una librería de Machine Learning para Python que soporta algoritmos de clasificación, regresión y clustering (wikipedia).
A continuación el notebook de jupyter:
Se creará una red neuronal para clasificación¶
Se usará la tabla de la verdad de XOR| x | y | Salida | |
|---|---|---|---|
| 0 | 0 | 0 | |
| 0 | 1 | 1 | |
| 1 | 0 | 1 | |
| 1 | 1 | 0 |
Para instalar scikit-learn se usa pip
pip3 install scikit-learnIn [4]:
##Se importa Numpy, MLPCCLassifier y KNeighborsClassifier
import numpy as np
from sklearn.neural_network import MLPClassifier
from sklearn.neighbors import KNeighborsClassifier
In [5]:
#un Arreglo con la tabla de la verdad
# 0 0
# 0 1
# 1 0
# 1 1
xs = np.array([
0, 0,
0, 1,
1, 0,
1, 1
]).reshape(4, 2)
xs
Out[5]:
In [6]:
#Se muestra un arreglo con el resultado de hacer un XOR
ys = np.array([0, 1, 1, 0]).reshape(4,)
ys
Out[6]:
In [7]:
#Se crea el clasificador con la función de activación relu,con 10k iteraciones y tiene capaz ocultas 4,2
model = MLPClassifier(activation='tanh', max_iter=10000, hidden_layer_sizes=(4,2))
model
Out[7]:
In [8]:
#Se entrena la red neuronal pasando los arreglos de entrada y de salida
model.fit(xs, ys)
Out[8]:
In [9]:
print('prediccion:', model.predict(xs)) # salida 0110
In [10]:
print('Se espera:', np.array([0, 1, 1, 0]))
Otro ejercicio¶
| Entrada | Salida | |
|---|---|---|
| 001 | 0 | |
| 111 | 1 | |
| 101 | 1 | |
| 011 | 0 | |
| 100 | ? |
In [11]:
#Se importa de numpy array
from numpy import array
In [12]:
#Datos de entrada y de salida
datos_entrada = array([[0, 0, 1], [1, 1, 1], [1, 0, 1], [0, 1, 1]]).reshape(4, 3)
datos_salida = array([[0, 1, 1, 0]]).reshape(4, )
print(datos_entrada)
print ("-"*4)
print(datos_salida)
In [13]:
#En este caso se usa KNeighborsClassifier con 2 capaz
KNC = KNeighborsClassifier(n_neighbors= 2)
In [14]:
KNC.fit(datos_entrada,datos_salida)
Out[14]:
In [15]:
#Se predice el valor de 1,0,0 que da como resultado el mismo del artículo anterior.
print(KNC.predict([[1, 0,0]]))
In [16]:
#Se crea la red de nuevo pero ahora con PLPCCLassifier.
#Se crea el clasificador con la función de activación relu,con 10k iteraciones y tiene capaz ocultas 4,2
KNC = MLPClassifier(activation='tanh', max_iter=10000, hidden_layer_sizes=(4,2))
In [17]:
#Se entrena la red neuronal pasando los arreglos de entrada y de salida
KNC.fit(datos_entrada, datos_salida)
Out[17]:
In [18]:
#Se predice el valor de 1,0,0 que da como resultado el mismo del artículo anterior.
print(KNC.predict([[1, 0,0]]))
En el siguiente artículo se explicará otro ejemplo de Árbol de decisión usando scikit-learn. +
+ 
+
+
+ La libertad de desarrollar...: WebScraping (extracción de datos) de wikipedia con Pandas
+Python Hispano 19 04 2018
+Continuando con la serie de artículos sobre Pandas, en este artículo se muestra un proceso de extracción de datos web de la página que contiene información sobre los Estados de Venezuela de Wikipedia.
En los procesos anteriores de WebScraping se trabajaba practicamente a mano para indentificar las secciones del código html donde se encuentra la información útil, para el caso con Pandas este abstrae ese proceso.
A continuación se muestra una captura de pantalla de la página donde se quiere extraer la información:
La información que maneja la página son los estados con sus capitales, densidad poblacional, superficie, año de admisión, población, densidad, región y código ISO, la parte de la bandera ni del mapa no se muestra por que son imágenes y no se obtiene información útil de ellas.
A continuación todo el proceso de extracción de información de la página:
In [1]:
#Se importa pandas como pd
import pandas as pd
#Se lee los datos de wikipedia de los estados de venezuela, este devuelve una lista
estados= pd.read_html('https://es.wikipedia.org/wiki/Estados_de_Venezuela')
estados
Out[1]:
In [2]:
#Tipo de los estados
type(estados)
Out[2]:
In [3]:
#Tipo del primer elemento es un dataframe
type(estados[0])
Out[3]:
In [4]:
#Se listan del dataframe estados y capitales (elementos 1 y 2 del dataframe, y se recorre)
for i in range(1,26):
print(estados[2][1][i],estados[2][2][i])
In [5]:
#Ahora se crea una lista de diccionarios donde estará la información de cada estado
lista = []
for i in range(1,26):
lista.append({'Estado':estados[2][1][i],
'Capital': estados[2][2][i],
'codigo_iso': estados[2][3][i],
u'año_admision': estados[2][4][i],
'Poblacion': int(estados[2][5][i].split(".")[0].split("&")[-1]),
'Superficie': int(estados[2][6][i].split(".")[0].split("&")[-1]),
'Densidad': float(estados[2][7][i].split(",")[0].split("&")[-1]),
'Region': estados[2][8][i]
})
print(lista)
In [6]:
#Luego se crea un dataframe de la lista de diccionarios
df = pd.DataFrame(lista)
df
Out[6]:
In [7]:
#Si se quiere la información de Carabobo
mascara = df["Estado"] == "Carabobo"
df[mascara]
Out[7]:
In [8]:
#Otra forma de traer la información de Carabobo
df.iloc[6]
Out[8]:
In [9]:
#Para obtener la capital del estado
df.iloc[6]["Capital"]
Out[9]:
In [ ]:
+ 
+
+
+ everytime
+MonkeyUser 17 04 2018
+
+
+
+
+ April Update - Preparing for Internationalisation
+WhoTracksMe blog 11 04 2018
+
+
+ Q2 2018 Survey Results and Call For Proposals
+News on Clojurists Together 10 04 2018
+
+
+ March 2018 Monthly Update
+News on Clojurists Together 03 04 2018
+
+
+ April 2018 Monthly Update
+News on Clojurists Together 03 04 2018
+
+ 
+
+
+ ICO
+MonkeyUser 03 04 2018
+
+
+ What’s the point of art?
+James Sinclair 01 04 2018
+
+
+ These months in Common Lisp: Q1 2018
+Lisp journey 01 04 2018
+Documentation
+ +-
+
- Multidimensional arrays – the Common Lisp Cookbook +
- Error and condition handling - the Common Lisp Cookbook +
- Scripting: parsing command line arguments, building self-contained executables - the Common Lisp Cookbook +
- ASDF Best Practices for 2018 +
- The Quicklisp local-projects mechanism +
- How to distribute your software, not library, on Quicklisp ala python pip +
- Common Lisp Brazil Community +
- Awesome Lisp companies +
- Announcing Quickref: a global documentation project for Common Lisp +
Announcements
+ + + +Projects
+ +-
+
- Next web browser +
- cl-repl, the Common Lisp ipython-like REPL +
- Emotiq - blockchain in Common Lisp +
- original reddit code from 2005. reddit. +
- Temperance - logic programming (in development, reached v1.0.0) +
- QR code 2005 encoder in Common Lisp +
- print-licences: print licenses used by the given project and its dependencies (from sjl and dk_jackdaniel’s utils) +
- Dufy, color library +
- cl-flow - Data-flowish computation tree library for non-blocking concurrent Common Lisp. +
- A docker container for CL development (also lisp-devel, CI on CL Cookbook) +
- Quickfork - Quicklisp for teams +
- Apache Thrift gains CL support +
- JSCL playground +
- MAGICL: Matrix Algebra proGrams In Common Lisp - Rigetti Computing +
- Eturia has been open-sourced. An Open Computer for Education for teaching #Lisp written in #Javascript. +
New releases:
+ +-
+
- Quicklisp dist update for february 2018 +
- SBCL 1.4.5 +
- Portacle 1.1 release: SBCL update, ASDF fixes +
- McCLIM 0.9.7 “Imbolc” release +
- Peter Norvig’s Paradigms of Artificial Intelligence Programming - book as pdf and lisp code on Github +
- cl-torrents 0.9 - readline interface and 1337x.to scraper +
Discoveries:
+ +-
+
- Folio2 - a collection of small libraries that provide support for functional idioms and data structures in Common Lisp; seamless integration of Series and FSet +
- Lisp Interface to Federal Reserve Economic Data (FRED®) +
- cl-bench benchmarking tool. reddit. +
- Screamer - nondeterministic programming. Augment Common Lisp with practically all of the functionality of both Prolog and constraint logic programming languages (10 yo, Nikodemus) +
- C-Mera, a Common Lisp source-to-source compiler to generate C/C++ +
- Regex, regular expression library in Common Lisp +
- Cells, spreadsheet-like expressiveness for CLOS +
Articles
+ +-
+
- Starting a minimal Common Lisp project +
- Emacs + ECL on Android +
- Generic, consistent and dotted access of data structures with Access - lisp-journey (reddit) +
- Quicklisp’s per-project build failures RSS feed +
- Quicklisp implementation stats for 2017+ +
- cl-charms crash course +
- LLVM’s garbage collection facilities and SBCL’s generational GC +
- A bunch of utilities from (again) sjl: higher order functions, sequences, debugging, profiling. +
- Sheets as ideal forms +
- The return of cl-notebook +
- Testing the SERIES package +
Discussion
+ +-
+
- Portacle hits #1 on Hackernews +
- What do you plan to work on in 2018? +
- Pros and cons of different ways to declare types in Common Lisp? +
- Has anyone considered or started a project to write a CL implementation in WebAssembly? +
- What do you recommend to work with SQL databases ? What’s your experience with Mito ? and sqlite only interface: cl-sqlite or cl-dbi ? +and is there an ORM that generates classes from table definitions ? +
- How to get asdf system dependencies +
- Join the cl-telegraph-bot refactoring effort ! +
- GUI development done in Lisp (2013 comment) +
- Strategies for Dealing with Large Amounts of Memory in Lisp? (SBCL) +
- GUI embedded plots in Lisp ? +
- Is there any non-lisp that copies Common Lisp’s condition system? +
Common Lisp VS …
+ +-
+
- As a newbie, what I will miss if I choose Racket over Common Lisp? Or if I happen to learn both at somepoint in future, choosing Racket/Common Lisp now would make sense? +
- What can other languages do that Lisp can’t ? +
Screencasts
+ +-
+
- Pushing Pixels with Lisp +
- Lisp Treehouse +
- Common Lisp study group 01-30-2018 (video) +
- Little bits of Lisp +
Jobs
+ +-
+
- Research Scientist Interactive Theorem Proving (using PVS, a Common Lisp application) +
- Lisp Engineer, Mind.ai +
- lisp-based domain specific language, compiler design +
- Seeking co-founder for Lisp game studio +
+ +
If we missed anything: https://gitlab.com/lisp-journey/lisp-journey.gitlab.io
+ +
+
+ End of Year Review 2017-18
+Blogs on Tom Spencer 31 03 2018
+
+
+ End of Year Review 2017-18
+Blogs on Tom Spencer 31 03 2018
+
+ 
+
+
+ Sprint Break
+MonkeyUser 27 03 2018
+
+
+ Migrating to Hugo
+Blogs on Tom Spencer 23 03 2018
+
+
+ Migrating to Hugo
+Blogs on Tom Spencer 23 03 2018
+
+
+
+
+ 10 juegos de GameBoy que quizás no recordabas
+Emezeta blog 21 03 2018
+
+ 
+
+
+ Compiler
+MonkeyUser 20 03 2018
+
+ 
+
+
+ Freak Spot: Internacionalización de programas Python
+Python Hispano 19 03 2018
+La +internacionalización +de programas permite que estos puedan ser entendidos por personas que +hablan idiomas diferentes.
+En este artículo enseño cómo internacionalizar un programa escrito en +Python 3. Para este propósito se suele utilizar el módulo +gettext, que esta +incluido en Python.
+ + +Antes de nada, debemos tener un programa para poder traducirlo. Vamos a
+traducir el siguiente programa llamado saluda.py:
#!/usr/bin/env python3
+
+nombre = input('¿Cómo te llamas? ')
+print('Hola, {}.'.format(nombre))
+El programa es muy sencillo. Pregunta al usuario su nombre y le saluda +por su nombre o, mejor dicho, le vuelve a repetir lo que el usuario ha +escrito.
+Para internacionalizar el programa anterior vamos a importar el módulo
+gettext y a ejecutar la función install de gettext. Después, debemos
+rodear el texto que queramos traducir con _(), es decir, si queremos
+traducir 'texto' escribiremos
+_('texto').
#!/usr/bin/env python3
+
+import gettext
+
+gettext.install('saluda', 'locale')
+
+nombre = input(_('¿Cómo te llamas? '))
+print(_('Hola, {}.').format(nombre))
+Ahora creamos el directorio locale, donde guardaremos las traducciones:
mkdir locale
+Después debemos ejecutar pygettext, que viene instalado con Python. +Quizás debéis ejecutar pygettext3 para indicar que queréis trabajar con +Python 3:
+pygettext -d saluda -p locale saluda.py
+Yo lo hice así desde la terminal:
+ +Ahora tenemos el archivo saluda.pot en el directorio locale. Para
+trabajar con archivos de traducción es recomendable usar un editor
+preparado para dicha tarea, porque hacerlo a mano es muy tedioso.
+Podemos usar el editor Poedit o cualquier otro editor diseñado para
+traducir.
Si vamos a utilizar Poedit, seleccionamos Archivo>Nueva desde archivo
+POT/PO y seleccionamos el archivo saluda.pot. A continuación,
+debemos seleccionar el idioma al que queremos traducir, yo voy a elegir
+el alemán.
+Cuando terminemos la traducción, debemos guardarla:
+ +
+Se generarán dos archivos: de.po y
+de.mo. El archivo de.po es legible por los humanos y el archivo
+de.mo es legible por la máquina. El archivo de.mo debe guardarse
+según la siguiente estructura de ficheros:
+locale/de/LC_MESSAGES/de.mo. Para que no tengamos que acordarnos de la
+anterior estructura cada vez que creemos o actualicemos una traducción,
+podemos ubicar el siguiente programa en el directorio locale y
+ejecutarlo cada vez que actualicemos un archivo .po:
#!/usr/bin/env python3
+# Copyright (C) 2016 Julie Marchant <onpon4@riseup.net>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import subprocess
+
+if __name__ == "__main__":
+ for fname in os.listdir():
+ root, ext = os.path.splitext(fname)
+ if ext == ".po":
+ print("Generando {}...".format(fname))
+ d, root = os.path.split(root)
+ os.makedirs(os.path.join(d, root, "LC_MESSAGES"), exist_ok=True)
+ oname = os.path.join(d, root, "LC_MESSAGES", "saluda.mo")
+ subprocess.call(["msgfmt", "-o", oname, fname])
+
+ print("Terminado.")
+Tras ejecutar el anterior programa, ya tendremos los archivos de
+traducción donde corresponden. Al ejecutar saluda.py se utilizará el
+idioma por defecto del sistema operativo que lo ejecute. Es decir, si
+estamos utilizando el alemán como el idioma predeterminado del sistema
+operativo, el programa se ejecutará en alemán. Podemos comprobar si
+funciona para este idioma cambiando la variable de entorno LANGUAGE en
+el caso de que estemos trabajando con GNU/Linux. Se puede probar así:
+
+ 
+
+
+ State of Clojure 2018 Results
+Clojure News 19 03 2018
+
+
+
+
+
+
+Welcome to the annual State of Clojure 2018 survey results! Thanks so much for taking the time to check in and provide your feedback. We are very fortunate to have data for some of these questions going all the way back to 2010, giving us a long view on how the data is trending. This year, we had 2325 respondents, about the same as last year.
+
+
+Rapid Uptake of Clojure 1.9
+
+
+
+
+With the release of Clojure 1.9 in December, we expected to see a shift in version usage, and we did. 72% of developers are already using it with about 60% still using Clojure 1.8 as well. Only a small (6%) number of developers are still using versions 1.7 or older.
+
+
+
+
+
+
+
+
+We also keep an eye on JDK usage. Uptake of Java 1.9, released last year, has been a bit slower with only 29% adopting Java 1.9 so far and 88% of developers using Java 1.8. Only 6% of developers are using Java 1.7 and less than 1% are still using Java 1.6.
+
+
+In the editor/IDE world we saw some consolidation this year with both Emacs (50%) and IntelliJ/Cursive (29%) making gains. All other editors saw decreases, although there is still a lot of interesting innovation happening around Atom and VS Code, which was not included but saw a lot of mentions in the comments (~5% of total respondents) - will definitely add next year!
+
+
+
+
+
+
+
+
+In the ClojureScript world, Figwheel continues to dominate as a critical part of most ClojureScript developer’s REPL workflow (76%). Clojurists Together is a new community effort to support open source projects in the community and they have been funding work on Figwheel among other projects. Lumo was a new REPL option this year and made a strong showing of 12%.
+
+
+
+
+
+
+
+
+In CLJS target environments, we saw an increase of +6% targeting Node (to 29%) and +4% targeting Lambda (to 13%) - both things to watch.
+
+
+In the build tooling world, the entry of the clj tool is driving a lot of reevaluation and change right now. With so many things in flux, this area is sure to evolve significantly in 2018 and it will be interesting to see where we are in 2019. One important omission in the choices this year was shadow-cljs. There were a lot of mentions in the comments and it’s clearly an important tool for many to build and deploy - we’ll be sure to add it next year.
+
+
+Interest Surging from JavaScript Programmers
+
+
+
+
+When we look at which language communities people are coming from, those answers have been remarkably stable for years, but there was significant movement this year for JavaScript (which vaulted over both Python and Ruby). Clearly people are finding ClojureScript (and its strong resonance with React) as an interesting and viable alternative to JavaScript.
+
+
+
+
+
+
+
+
+As to where Clojurists hang out, we saw significant increases in use of Reddit (+5%) and Slack (+4%) and some decreases in use of the Clojure mailing lists, IRC, and attendance at both in-person and on-line conferences. One new choice added this year was the ClojureVerse Discourse server - it seems to be a useful midpoint between Slack (high volume live chat) and mailing lists (low volume asynchronous discussion). This was a new option yet 17% of respondents reported using it.
+
+
+
+
+
+
+
+
+Clojure and ClojureScript Used in Many Domains and Industries
+
+
+
+
+One of the things we are always watching is the trend of people using Clojure for their day-to-day work. This year, we continued to see about 2/3 of respondents using Clojure for work (compare that to the very first survey back in 2010 when less than 1/3 were doing so). Web development has always been the most dominant domain - in 2010, 53% were doing web dev and these days fully 82% of Clojure devs are involved in some kind of web development (not surprising given how many Clojure devs are using both Clojure and ClojureScript together).
+
+
+
+
+
+
+
+
+When looking at the industries using Clojure, we added a few choices this year based on prominent results in last year’s "Other" category - entertainment (3%), energy/utility (2%), automotive/manufacturing (2%). We also saw a noticeable increase (+3%) in Financial services. Perhaps due to the new choices, we saw small decreases in the largest and most generic categories, enterprise software and consumer software.
+
+
+
+
+
+
+
+
+Interest in Hiring Stays Strong
+
+
+
+
+There are several questions about how Clojure and ClojureScript should change or be prioritized for improvement. The results are largely similar to prior years, although the question format changed a little making it hard to directly compare every detail. The top result is clearly error messages though - while spec has started us down a road, that is still a work in progress which will continue this year. Many people have been using the Expound library for taking spec error output and making the data easier to read.
+
+
+Hiring and staffing is always an interesting one to watch and that increased this year. We often see the seemingly contradictory dual complaints of companies that need more people and developers that have a hard time finding positions. To a large degree this is either a mismatch in the geographic distribution of jobs and people and/or a mismatch in needs and skill levels. It has been very encouraging to see so many large teams growing and hiring of late though.
+
+
+The need for more docs and tutorials is also one that has gone up and down over the years and seems to be up again this year. While there are a wealth of resources for new Clojure developers now in every format, it is also sometimes difficult for people to find just the right resource for their experience level and need. There have been many good discussions lately about this and lots of active work in the community.
+
+
+In general, there have been so many new tools, learning resources, companies, etc of late that it’s hard to keep up - 2018 is going to be a great year for Clojure!
+
+
+
+ Check Out the Data
+
+
+
+
+
+If you’d like to dig into the full results, you can find the complete set of data from this and former years here:
+
+
+Note that we are doing the survey about every 14 months so the last survey occurred in late 2016 rather than 2017.
+
+
+Thanks again for being part of the community!
+
+ 
+
+
+ Programador Web Valencia: Tutorial Flask para crear un API REST con VueJS
+Python Hispano 18 03 2018
+
Introducción
+ +En el siguiente tutorial con Flask vamos a construir un API REST completa paso a paso en 18 sencillos temas. Aprenderemos a trabajar con Flask, a realizar un esquema sencillo, a conectar con una base de datos, realizar un CRUD, a conectar con una base de datos, crear una interfaz con VueJS, e integrarlo todo con comodidad. Todos temas son accesibles desde cada rama del repositorio.
+ +El objetivo no es aburrirte con infinitas explicaciones, sino darte nociones reales para trabajar. De ese modo podrás experimentar revisando el código que te dejo en cada tema.
+ +Indice
+ +-
+
- Tema 1: Flask + + +
- Tema 2: API Rest + + +
- Tema 3: Base de datos + + +
- Tema 4: Vue-cli + + +
Objetivo final
+ + + +
Necesitaremos
+ +-
+
- Portátil, y tuyo. +
- Python 3.5> +
- Internet superior a 56k +
- Editor de texto enriquecido y con fundamento. +
- httpie +
- pipenv +
¿Bibliotecas?
+ +Microframework Web
+ +-
+
- Flask. +
Base de datos
+ +-
+
- Flask-SQLAlchemy: ORM +
- Flask-Migrate: Añade herramientas para gestionar nuestra base de datos. +
- Flask-Script: Creación de comandos personalizados +
- Faker: Generador de información falsa +
API Rest
+ +-
+
- Flask-restplus: Nos ayuda con las peticiones y autodocumentación +
- Flask-JWT: Identificación básica. +
- Flask-marshmallow: Convertirá los objetos ORM en JSON. +
- Flask-CORS: Nos permitirá peticiones desde el exterior. +
Herramientas de desarrollo
+ +-
+
- httpie: Cliente de API Rest para pruebas. +
- python-dotenv: Implementación de un archivo de configuración. +
Instalación
+ +Si estas en Debian/Ubuntu, antes necesitarás.
+ +sudo apt-get install python3-venv¡Ahora sí!
+ +git clone git@github.com:tanrax/workshop-flask-with-vuejs.git
+cd workshop-flask-with-vuejs
+python3 -m venv venv
+source venv/bin/activate
+pip3 install -r requirements.txt¿Empezamos?
+ + + +¡Pista para programadores!
+ +Para seguir el taller sin perderte puedes ir saltando a los 🎈checkpoints🎈 de la siguiente manera.
+ +git checkout tema1-1
+ 
+
+
+ The Struggle
+MonkeyUser 13 03 2018
+
+
+ Nine months with Vim
+Posts on James Routley 11 03 2018
+
+
+ Tip: capture standard and error output
+Lisp journey 06 03 2018
+What if we want to capture standard (and/or error) output in order to +ignore it or post-process it ? It’s very simple, a +little search +and we’re good:
+ +(let ((*standard-output* (make-string-output-stream))
+ (*error-output* (make-string-output-stream)))
+ (apply function args) ;; anything
+ (setf standard-output (get-output-stream-string *standard-output*)))
+(print-results standard-output))
+and now in print-results we can print to standard output without
+being intercepted (and in our case, we’ll highlight some user-defined
+keywords).
Above, just don’t forget to get the output content with
+(get-output-stream-string *standard-output*).
A thing to note is that if your app printed stuff on error output and +standard output consecutively, now it will print all standard output +as a single block.
+ +(edit) Of course, with-output-to-string is simpler to capture one stream:
(setf standard-output (with-output-to-string (*standard-output*)
+ (apply function args)))
+edit 2, thanks to redditers:
+ +Don’t bind standard-output directly; bind the string stream to a
+lexical, then bind *standard-output* to that:
(with-output-to-string (s)
+ (let ((*standard-output* s)) (write-string "abc")))
+-> "abc"
+Now, let’s bind both *standard-output* and *standard-error* to s:
(with-output-to-string (s)
+ (let ((*standard-output* s)
+ (*standard-error* s))
+ (write-string "abc")
+ (write-string "def" *standard-error*)))
+-> "abcdef"
+Eliminate s and just bind *standard-output* and then tie
+*standard-error* to the same stream:
(with-output-to-string (*standard-output*)
+ (let ((*standard-error* *standard-output*))
+ (write-string "abc")
+ (write-string "def" *standard-error*)))
+--> "abcdef"
+The conclusion stays: it’s handy and easy :)
+ +
+ 
+
+
+ Focus
+MonkeyUser 06 03 2018
+
+
+ The “dot” command in Vim
+Jovica Ilic 02 03 2018
+I believe you have already heard of the principle Don’t Repeat Yourself. In software engineering, this is a principle of software development where your focus is on reducing repetition of all kinds. As you’ll see throughout the book, Vim has many ways and commands to automate different kinds of tasks, so you don’t have to... Continue reading
+The post The “dot” command in Vim appeared first on Jovica Ilic.
+ +
+
+ February 2018 Monthly Update
+News on Clojurists Together 01 03 2018
+
+
+ Pico-8 Game of life
+Posts on James Routley 25 02 2018
+
+ 
+
+
+ Demo
+MonkeyUser 19 02 2018
+
+
+ Your First Vim Session
+Jovica Ilic 16 02 2018
+The major barrier to any skill acquisition isn’t intellectual, but emotional. The same goes for learning Vim. That’s why, as one of the first chapters in my book Mastering Vim Quickly, I teach how to do something very cool. It’s very motivational, especially for someone who is new to the Vim world. You see you... Continue reading
+The post Your First Vim Session appeared first on Jovica Ilic.
+ +
+ 
+
+
+ Testing during development
+MonkeyUser 13 02 2018
+
+
+ Fixing a CL21 error message in an unrelated library after a quicklisp update (it's about cache)
+Lisp journey 12 02 2018
+I just updated my Quicklisp dist and suddenly couldn’t load some +libraries any more. I got an error related to cl21 looking like the one below +(I didn’t note the exact message sorry), even though the library was +unrelate to cl21 (it was about osicat and cffi.grovel):
+ +++ +couldn’t find adjustable-vectors from CL21.core.arrays
+
If you skip through the restarts you’ll see mentions of a cache in
+~/.cache/common-lisp/sbclxx-xx/quicklisp/…. It contains the compiled .fasl files.
I deleted this cache and I’m good to go.
+ ++ + + +
+
+ Q1 2018 Funding Announcement
+News on Clojurists Together 07 02 2018
+
+ 
+
+
+ Debugging
+MonkeyUser 06 02 2018
+
+
+
+
+
+
+ February Update - The Tracking Shell Game
+WhoTracksMe blog 05 02 2018
+
+
+ Q1 2018 Update and Survey Results
+News on Clojurists Together 31 01 2018
+
+ 
+
+
+ Perspectives
+MonkeyUser 30 01 2018
+
+
+ 9 Django Tips for Working with Databases
+Haki Benita 28 01 2018
+ORMs offer great utility for developers but abstracting access to the database has its costs. Developers who are willing to poke around the database and change some defaults often find that great improvements can be made.
+
+ 
+
+
+ 10 Years of Instapaper
+Instapaper 28 01 2018
+On January 28, 2008, Marco Arment announced a new side project called Instapaper. Ten years and billions of articles later, we’re thrilled to be helping our readers learn, research and experience the Internet removed from the typical distractions.
First, we want to thank all of our users. Whether you’ve been around since the Marco days, joined us when betaworks took over the development or signed up after our acquisition by Pinterest, thank you! We wouldn’t be anywhere without you, and we look forward to incorporating your requests into our 2018 updates.
In Internet years a decade is a century. Instapaper predates the App Store, Google Chrome and the entire Android OS, so we wanted to take this opportunity to look back on some of our product and business milestones.
2008
At launch, Instapaper was more of a bookmarking tool than the full-featured reading product it is today. Users could save items to their Instapaper list and then go view the original website at their convenience.
In April, we introduced “Text mode” to reduce load times for slower phone connections. The parser behind that feature remains one of the most foundational and innovative components of Instapaper today.
Apple launched its App Store in July, and we were one of the first apps available. Instapaper got over 2,000 downloads on its first day (and more than 15,000 downloads before the end of the month), and we got our first of many App Store features.
By the end of the year, we also added the first proper offline mode, more fonts, the Archive section, “Give me something to read” (the precursor to the current Daily/Feature content), tilt-scroll and our first business model–a separate version of the app called Instapaper Pro which cost $9.99.
2009
With the core function of processing content for offline reading in place, 2009 was all about adding more ways to get content into and out of Instapaper with the launch of our API in January, Kindle support and Likes in March, folders and background updating in June and ePub and Kindle exports in November.
Instapaper Pro went on sale, and $4.99 became the new price for the paid version of the app.
2010
As more users saved more content, we introduced a bulk edit option for easier content management and paywall/multi-page support to improve saving overall. The app got a slight facelift for our iPad debut as well as the addition of pagination mode, themes, auto-dark mode, in-app dictionary, and length indicators for saves.
In October, Instapaper launched an optional subscription for $1 per-month to help support our operation and future feature development. Eventually, Instapaper’s full-text search feature would launch exclusively for subscribers.
To close out the year, Instapaper was added to Apple’s Hall of Fame and awarded a Macworld editors’ choice award.
2011
This was the year we got even more connected, with a full API launch, social sharing in the Instapaper 3.0 release, a brand new dictionary and zoomable images. It also was the year the FBI may have unintentionally confiscated–and later returned–one of our servers during an unrelated raid.
Additionally, the free version of our app was removed from the App Store, leaving only the $4.99 Instapaper Pro version.
2012
In 2012, our bookmarklet got a facelift, with a more prominent overlay, and confirmation and automatic multi-page save capability. The iOS app also got iBooks-style pagination mode, the option to manually select twilight sepia at any time and swipe gestures in Instapaper 4.2. In June, we released the first version of Instapaper for Android for $2.99 and dropped the price of the iOS app to $3.99. Lastly, we added support for the OpenDyslexie and FS Me fonts to improve accessibility.
2013
Instapaper was acquired by betaworks in 2013. With a new team in place, we worked on backend infrastructure improvements, a site redesign, a Chrome extension launch and the development of InstaRank, which was our first attempt to gain insight into aggregate reading trends across the service.
The apps also got major updates with Instapaper 5.0 for iOS 7, including a modern user interface, video support, parsing improvements and localization for 13 languages in September; an Android app redesign in October; and an iPad redesign in November.
The year was rounded out with the launch of the InstaRank-based Instapaper Daily, a compilation of the most popular articles saved to Instapaper every day.
2014
With steady Instapaper Daily engagement, the articles from that feed became part of Instapaper’s Browse section and we began sending out a compilation of Daily articles as an email digest called Instapaper Weekly.
In May, Instapaper.com was fully redesigned. Highlights was introduced and has since become one of our most-used features. Also, after years of using Georgia (a standard serif font), we got our first “real logo” from Klim Type Foundry:
The App Store landscape had changed dramatically since 2008, and by September 2014 it made the most sense for us to transition Instapaper into a freemium product, marking the first time Instapaper was offered for free on the App Store since the removal of “Instapaper Free” in 2011.
In the same release, we added the iOS save extension, text-to-speech and public profiles. In the subsequent 6.1 update, Instapaper got its current slim save overlay, unread counts and handoff support for seamlessly picking up where you left off from your iPhone, iPad or the website.
2015
Highlights were a great tool for pulling out key phrases in saves but a lot of users were asking to annotate what they were highlighting. That’s why we added Notes, the ability to add annotations to your Instapaper saves.
In addition to Notes, we implemented a speed reading feature and Instant Sync support in Instapaper 6.2 as well as an Apple Watch app for triggering text-to-speech. Instapaper 7 smoothed up all these developments and also included the addition of thumbnails, an iPad redesign, multi-task support and picture-in-picture for video playback.
2016
After adding so many new features, it was essential to bring legacy parts of Instapaper up to the same level. In January, we completely rewrote the parser and launched the first version of the current Instaparser. With Instaparser 1.0, we added enhanced video support, way better image handling, more aggressive stripping of non-article text and performance improvements that led to 10x faster saving.
Search was next on the update block. First, we overhauled search infrastructure entirely to improve speeds by 6x and allow us to add new features including sorting options, title searches, exact matches, site/author filtering, paged results and multi-language sort. With the new infrastructure in place, we then revamped mobile search to allow for local offline search, as well as searching for and opening items outside the device sync limit in Instapaper formatting.
Instapaper opened a few new business models in 2016, including the Instapaper Weekly Sponsorship and the Instaparser developer API, which allowed third-party developers to use our article parser.
In August, Instapaper joined Pinterest, where we continue to operate as a separate, standalone product. With added resources under Pinterest, we were able to make Instapaper Premium free for all users.
2017
Disaster struck in early 2017, as we experienced our first major, extended outage. While there was no data loss, Instapaper was offline for 20 hours, and it took almost five days to completely restore the service (quite the departure from our uptime of 99.93% the previous year).
On a more positive note, that year also included the launch of our Firefox extension, an iOS 11-optimized update with drag & drop support and an iPhone X-specific update that was featured on launch at Apple’s new App Store.
2018
This year, and beyond, we’ll continue the tradition of the past decade: offering a no-frills, high-quality service with total focus on the reader and the reading experience.
Whether you use text-to-speech in the car, speed reading to read faster, highlights for your research or just read the good-old fashioned way. We look forward to helping you read and learn.
We’d also like to reward anyone who made it all the way through this post, so if you send us an email to support@help.instapaper.com with your mailing address, we’ll send you some Instapaper stickers (U.S.-only, while stickers last).
If you have any requests for what you’d like to see in Instapaper or just want to say hello, please let us know via support@help.instapaper.com or @InstapaperHelp on Twitter.
+
+ 
+
+
+ Backtesting 12-month SMA investing strategy with Pandas
+Danny van Kooten 24 01 2018
+In my quest to learn more about investing, I came across this post. The author writes “How One Simple Rule Can Beat Buy and Hold Investing” and then explains how following the trend is likely to beat a more traditional buy and hold investment approach.
+ +Intrigued, I decided to dive into the data to see if I could replicate his results.
+ +In this post I’ll walk you through the code and results for backtesting a 12-month simple moving average trend strategy on S&P 500 stock market data.
+ +We’ll compare entering the market when it is trending up and moving to cash when it is trending down to simply staying invested at all times. The latter approach is known as buy & hold, or HODL depending on what corner of the internet you’re from.
+ +Obtaining data on daily closing prices for the S&P 500
+ +First things first, we need data.
+ +Yahoo Finance provides us with historical data for the S&P 500 as far back as 1960. Let’s start out with parsing the CSV download into a DataFrame so we can get to work.
+ +%matplotlib inline
+import pandas as pd
+
+sp500 = pd.read_csv('data/SP500.csv', sep=',', parse_dates=True, index_col='Date', usecols=['Adj Close', 'Date'])
+sp500.head()
+| + | Adj Close | +
|---|---|
| Date | ++ |
| 1960-01-04 | +59.910000 | +
| 1960-01-05 | +60.389999 | +
| 1960-01-06 | +60.130001 | +
| 1960-01-07 | +59.689999 | +
| 1960-01-08 | +59.500000 | +
Calculating the 12 month simple moving average
+ +To test our trend strategy later on, we need the daily change (in %) and the 12-month simple moving average.
+ +sp500['Pct Change'] = sp500['Adj Close'].pct_change()
+sp500['SMA 365'] = sp500['Adj Close'].rolling(window=365).mean()
+sp500.dropna().head()
+| + | Adj Close | +Pct Change | +SMA 365 | +
|---|---|---|---|
| Date | ++ | + | + |
| 1961-06-14 | +65.980003 | +0.002736 | +58.350521 | +
| 1961-06-15 | +65.690002 | +-0.004395 | +58.366356 | +
| 1961-06-16 | +65.180000 | +-0.007764 | +58.379479 | +
| 1961-06-19 | +64.580002 | +-0.009205 | +58.391671 | +
| 1961-06-20 | +65.150002 | +0.008826 | +58.406630 | +
This leaves us with all the data we need to compare our two investment strategies.
+ +Defining the trend strategy
+ +To recap, we want to invest when the trend is moving up, ie when the stock price is higher than the average price over the last 12 months. When the stock is traded at a price lower than the moving average, we move to cash.
+ +Let’s add a column to our dataframe indicating whether the criteria for our trend strategy is met.
+ +sp500['Criteria'] = sp500['Adj Close'] >= sp500['SMA 365']
+sp500['Criteria'].value_counts()
+True 10577
+False 4032
+Name: Criteria, dtype: int64
+This tells us that on our entire dataset, our criteria was met on 10577 of the market’s trading days.
+ +Calculating our investment return
+ +To calculate the return for our benchmark buy & hold strategy, all we need to do is calculate the cumulative product of the daily change in prices.
+ +Let’s assume an initial investment of $100 and calculate the return if we were to hold for the entire time period.
+ +sp500['Buy & Hold'] = 100 * (1 + sp500['Pct Change']).cumprod()
+To calculate the return for our strategy, we should only add the compounded return for the days on which we are actually in the market.
+ +On all other days the cash value of our investment remains unchanged.
+ +sp500['Trend'] = 100 * (1 + ( sp500['Criteria'].shift(1) * sp500['Pct Change'] )).cumprod()
+Let’s plot the values of both strategies in a single graph so that we can compare performances.
+ +ax = sp500[['Trend', 'Buy & Hold']].plot(grid=True, kind='line', title="Trend (12 month SMA) vs. Buy & Hold", logy=True)
+
This shows us that a simple buy & hold investing approach actually outperformed our trend strategy when looking at the S&P 500 market data for 1960 to early 2018.
+ +Seeking outperformance
+ +Looking at the graph above, you can see that the trend did well during ongoing bear markets but sometimes failed to pick up on quick market recoveries.
+ +Let’s cheat a little bit and look at “the lost decade”, which contains not just one but two relatively long bear markets!
+ +
This shows us that our trend strategy resulted in considerable outperformance during the last 2 decades, but only because of the two bear markets.
+ +Conclusion: Trend following over Buy & Hold?
+ +After playing with the data and looking at several time periods, I am still firmly in the “buy & hold” camp and think it is the way to go for most individual investors.
+ +With some curve fitting, we can make the trend model outperform over some specific time periods like the 2000’s. Increase the holding period and this outperformance does not last though.
+ +You can find the complete Jupyter Notebook for this post here.
+ +
+
+ snippets - functional style, sequences, debugging and more utilities
+Lisp journey 23 01 2018
+From +sjl’s utilities +(thanks so much for the nice docstrings). The goal here is to read +some code and learn about (hidden) gems.
+ +The following snippets should be copy-pastable. They are the ones I +find most interesting, I left some behind.
+ +To reduce the dependency load, Alexandria or Quickutil functions can +be imported one by one with Quickutil.
+ + + +Table of Contents
+ + + + + +Higher order functions
+ +See also https://github.com/mikelevins/folio2 and How to do functional programming in CL.
+ +(defun juxt (&rest functions)
+ "Return a function that will juxtapose the results of `functions`.
+ This is like Clojure's `juxt`. Given functions `(f0 f1 ... fn)`, this will
+ return a new function which, when called with some arguments, will return
+ `(list (f0 ...args...) (f1 ...args...) ... (fn ...args...))`.
+ Example:
+ (funcall (juxt #'list #'+ #'- #'*) 1 2)
+ => ((1 2) 3 -1 2)
+ "
+ (lambda (&rest args)
+ (mapcar (alexandria:rcurry #'apply args) functions)))
+(defun nullary (function &optional result)
+ "Return a new function that acts as a nullary-patched version of `function`.
+ The new function will return `result` when called with zero arguments, and
+ delegate to `function` otherwise.
+ Examples:
+ (max 1 10 2) ; => 10
+ (max) ; => invalid number of arguments
+ (funcall (nullary #'max)) ; => nil
+ (funcall (nullary #'max 0)) ; => 0
+ (funcall (nullary #'max 0) 1 10 2) ; => 10
+ (reduce #'max nil) ; => invalid number of arguments
+ (reduce (nullary #'max) nil) ; => nil
+ (reduce (nullary #'max :empty) nil) ; => :empty
+ (reduce (nullary #'max) '(1 10 2)) ; => 10
+ "
+ (lambda (&rest args)
+ (if (null args) result (apply function args))))
+(defmacro gathering (&body body)
+ ;; https://github.com/sjl/cl-losh/blob/master/losh.lisp#L515
+ "Run `body` to gather some things and return a fresh list of them.
+ `body` will be executed with the symbol `gather` bound to a function of one
+ argument. Once `body` has finished, a list of everything `gather` was called
+ on will be returned.
+ It's handy for pulling results out of code that executes procedurally and
+ doesn't return anything, like `maphash` or Alexandria's `map-permutations`.
+ The `gather` function can be passed to other functions, but should not be
+ retained once the `gathering` form has returned (it would be useless to do so
+ anyway).
+ Examples:
+ (gathering
+ (dotimes (i 5)
+ (gather i))
+ =>
+ (0 1 2 3 4)
+ (gathering
+ (mapc #'gather '(1 2 3))
+ (mapc #'gather '(a b)))
+ =>
+ (1 2 3 a b)
+ "
+ (with-gensyms (result)
+ `(let ((,result (make-queue)))
+ (flet ((gather (item)
+ (enqueue item ,result)))
+ (declare (dynamic-extent #'gather))
+ ,@body)
+ (queue-contents ,result))))
+Here we need the queue struct.
(defstruct (queue (:constructor make-queue))
+ (contents nil :type list)
+ (last nil :type list)
+ (size 0 :type fixnum))
+
+;; real code is richer, with inline and inlinable function declarations.
+
+(defun make-queue ()
+ "Allocate and return a fresh queue."
+ (make-queue%))
+
+(defun queue-empty-p (queue)
+ "Return whether `queue` is empty."
+ (zerop (queue-size queue)))
+
+(defun enqueue (item queue)
+ "Enqueue `item` in `queue`, returning the new size of the queue."
+ (let ((cell (cons item nil)))
+ (if (queue-empty-p queue)
+ (setf (queue-contents queue) cell)
+ (setf (cdr (queue-last queue)) cell))
+ (setf (queue-last queue) cell))
+ (incf (queue-size queue)))
+
+(defun dequeue (queue)
+ "Dequeue an item from `queue` and return it."
+ (when (zerop (decf (queue-size queue)))
+ (setf (queue-last queue) nil))
+ (pop (queue-contents queue)))
+
+(defun queue-append (queue list)
+ "Enqueue each element of `list` in `queue` and return the queue's final size."
+ (loop :for item :in list
+ :for size = (enqueue item queue)
+ :finally (return size)))
+Sequences
+ +(defun frequencies (sequence &key (test 'eql))
+ ;; https://github.com/sjl/cl-losh/blob/master/losh.lisp#L1910
+ "Return a hash table containing the frequencies of the items in `sequence`.
+ Uses `test` for the `:test` of the hash table.
+ Example:
+ (frequencies '(foo foo bar))
+ => {foo 2
+ bar 1}
+ "
+ (iterate
+ (with result = (make-hash-table :test test))
+ (for i :in-whatever sequence)
+ (incf (gethash i result 0))
+ (finally (return result))))
+(defun proportions (sequence &key (test 'eql) (float t))
+ "Return a hash table containing the proportions of the items in `sequence`.
+ Uses `test` for the `:test` of the hash table.
+ If `float` is `t` the hash table values will be coerced to floats, otherwise
+ they will be left as rationals.
+ Example:
+ (proportions '(foo foo bar))
+ => {foo 0.66666
+ bar 0.33333}
+ (proportions '(foo foo bar) :float nil)
+ => {foo 2/3
+ bar 1/3}
+ "
+ (let* ((freqs (frequencies sequence :test test))
+ (total (reduce #'+ (hash-table-values freqs)
+ :initial-value (if float 1.0 1))))
+ (mutate-hash-values (lambda (v) (/ v total))
+ freqs)))
+(defun group-by (function sequence &key (test #'eql) (key #'identity))
+ "Return a hash table of the elements of `sequence` grouped by `function`.
+ This function groups the elements of `sequence` into buckets. The bucket for
+ an element is determined by calling `function` on it.
+ The result is a hash table (with test `test`) whose keys are the bucket
+ identifiers and whose values are lists of the elements in each bucket. The
+ order of these lists is unspecified.
+ If `key` is given it will be called on each element before passing it to
+ `function` to produce the bucket identifier. This does not effect what is
+ stored in the lists.
+ Examples:
+ (defparameter *items* '((1 foo) (1 bar) (2 cats) (3 cats)))
+ (group-by #'first *items*)
+ ; => { 1 ((1 foo) (1 bar))
+ ; 2 ((2 cats))
+ ; 3 ((3 cats)) }
+ (group-by #'second *items*)
+ ; => { foo ((1 foo))
+ ; bar ((1 bar))
+ ; cats ((2 cats) (3 cats)) }
+ (group-by #'evenp *items* :key #'first)
+ ; => { t ((2 cats))
+ ; nil ((1 foo) (1 bar) (3 cats)) }
+ "
+ (iterate
+ (with result = (make-hash-table :test test))
+ (for i :in-whatever sequence)
+ (push i (gethash (funcall function (funcall key i)) result))
+ (finally (return result))))
+
+
+(defun take-list (n list)
+ (iterate (declare (iterate:declare-variables))
+ (repeat n)
+ (for item :in list)
+ (collect item)))
+
+(defun take-seq (n seq)
+ (subseq seq 0 (min n (length seq))))
+(defmacro do-repeat (n &body body)
+ "Perform `body` `n` times."
+ `(dotimes (,(gensym) ,n)
+ ,@body))
+(defmacro do-range (ranges &body body)
+ "Perform `body` on the given `ranges`.
+
+ Each range in `ranges` should be of the form `(variable from below)`. During
+ iteration `body` will be executed with `variable` bound to successive values
+ in the range [`from`, `below`).
+
+ If multiple ranges are given they will be iterated in a nested fashion.
+
+ Example:
+
+ (do-range ((x 0 3)
+ (y 10 12))
+ (pr x y))
+ ; =>
+ ; 0 10
+ ; 0 11
+ ; 1 10
+ ; 1 11
+ ; 2 10
+ ; 2 11
+
+ "
+ (if (null ranges)
+ `(progn ,@body)
+ (destructuring-bind (var from below) (first ranges)
+ `(loop :for ,var :from ,from :below ,below
+ :do (do-range ,(rest ranges) ,@body)))))
+(defun enumerate (sequence &key (start 0) (step 1) key)
+ "Return an alist of `(n . element)` for each element of `sequence`.
+ `start` and `step` control the values generated for `n`, NOT which elements of
+ the sequence are enumerated.
+ Examples:
+ (enumerate '(a b c))
+ ; => ((0 . A) (1 . B) (2 . C))
+ (enumerate '(a b c) :start 1)
+ ; => ((1 . A) (2 . B) (3 . C))
+ (enumerate '(a b c) :key #'ensure-keyword)
+ ; => ((0 . :A) (1 . :B) (2 . :C))
+ "
+ (iterate (for el :in-whatever sequence)
+ (for n :from start :by step)
+ (collect (cons n (if key
+ (funcall key el)
+ el)))))
+uses iterate, on Quicklisp (see also Shinmera’s For).
The followingtake is taken from Serapeum (also available in CL21).
The original helpers (take-list, etc) are originally inlined for optimal performance +with a custom “defun-inline”.
+ +(defun take (n seq)
+ "Return a fresh sequence of the first `n` elements of `seq`.
+ The result will be of the same type as `seq`.
+ If `seq` is shorter than `n` a shorter result will be returned.
+ Example:
+ (take 2 '(a b c))
+ => (a b)
+ (take 4 #(1))
+ => #(1)
+ From Serapeum.
+ "
+ (check-type n array-index)
+ (ctypecase seq
+ (list (take-list n seq))
+ (sequence (take-seq n seq))))
+
+(defun take-list (n list)
+ (iterate (declare (iterate:declare-variables))
+ (repeat n)
+ (for item :in list)
+ (collect item)))
+
+(defun take-seq (n seq)
+ (subseq seq 0 (min n (length seq))))
+(defun take-while-list (predicate list)
+ (iterate (for item :in list)
+ (while (funcall predicate item))
+ (collect item)))
+
+(defun take-while-seq (predicate seq)
+ (subseq seq 0 (position-if-not predicate seq)))
+
+(defun take-while (predicate seq)
+ "Take elements from `seq` as long as `predicate` remains true.
+ The result will be a fresh sequence of the same type as `seq`.
+ Example:
+ (take-while #'evenp '(2 4 5 6 7 8))
+ ; => (2 4)
+ (take-while #'evenp #(1))
+ ; => #()
+ "
+ (ctypecase seq
+ (list (take-while-list predicate seq))
+ (sequence (take-while-seq predicate seq))))
+(defun drop-list (n list)
+ (copy-list (nthcdr n list)))
+
+(defun drop-seq (n seq)
+ (subseq seq (min n (length seq))))
+
+(defun drop (n seq)
+ "Return a fresh copy of the `seq` without the first `n` elements.
+ The result will be of the same type as `seq`.
+ If `seq` is shorter than `n` an empty sequence will be returned.
+ Example:
+ (drop 2 '(a b c))
+ => (c)
+ (drop 4 #(1))
+ => #()
+ From Serapeum.
+ "
+ (check-type n array-index)
+ (ctypecase seq
+ (list (drop-list n seq))
+ (sequence (drop-seq n seq))))
+(defun drop-while-list (predicate list)
+ (iterate (for tail :on list)
+ (while (funcall predicate (first tail)))
+ (finally (return (copy-list tail)))))
+
+(defun drop-while-seq (predicate seq)
+ (let ((start (position-if-not predicate seq)))
+ (if start
+ (subseq seq start)
+ (subseq seq 0 0))))
+
+(defun drop-while (predicate seq)
+ "Drop elements from `seq` as long as `predicate` remains true.
+ The result will be a fresh sequence of the same type as `seq`.
+ Example:
+ (drop-while #'evenp '(2 4 5 6 7 8))
+ ; => (5 6 7 8)
+ (drop-while #'evenp #(2))
+ ; => #(2)
+ "
+ (ctypecase seq
+ (list (drop-while-list predicate seq))
+ (sequence (drop-while-seq predicate seq))))
+(defun extrema (predicate sequence)
+ "Return the smallest and largest elements of `sequence` according to `predicate`.
+ `predicate` should be a strict ordering predicate (e.g. `<`).
+ Returns the smallest and largest elements in the sequence as two values,
+ respectively.
+ "
+ (iterate (with min = (elt sequence 0))
+ (with max = (elt sequence 0))
+ (for el :in-whatever sequence)
+ (when (funcall predicate el min) (setf min el))
+ (when (funcall predicate max el) (setf max el))
+ (finally (return (values min max)))))
+(defun summation (sequence &key key)
+ "Return the sum of all elements of `sequence`.
+ If `key` is given, it will be called on each element to compute the addend.
+ This function's ugly name was chosen so it wouldn't clash with iterate's `sum`
+ symbol. Sorry.
+ Examples:
+ (sum #(1 2 3))
+ ; => 6
+ (sum '(\"1\" \"2\" \"3\") :key #'parse-integer)
+ ; => 6
+ (sum '(\"1\" \"2\" \"3\") :key #'length)
+ ; => 3
+ "
+ (if key
+ (iterate (for n :in-whatever sequence)
+ (sum (funcall key n)))
+ (iterate (for n :in-whatever sequence)
+ (sum n))))
+(defun product (sequence &key key)
+ ;; https://github.com/sjl/cl-losh/blob/master/losh.lisp#L2181
+ "Return the product of all elements of `sequence`.
+ If `key` is given, it will be called on each element to compute the
+ multiplicand.
+ Examples:
+ (product #(1 2 3))
+ ; => 6
+ (product '(\"1\" \"2\" \"3\") :key #'parse-integer)
+ ; => 6
+ (product '(\"1\" \"2\" \"3\") :key #'length)
+ ; => 1
+ "
+ (if key
+ (iterate (for n :in-whatever sequence)
+ (multiplying (funcall key n)))
+ (iterate (for n :in-whatever sequence)
+ (multiplying n))))
+Debugging and logging
+ +(defun pr (&rest args)
+ "Print `args` readably, separated by spaces and followed by a newline.
+ Returns the first argument, so you can just wrap it around a form without
+ interfering with the rest of the program.
+ This is what `print` should have been.
+ "
+ (format t "~{~S~^ ~}~%" args)
+ (finish-output)
+ (first args))
+(defmacro prl (&rest args)
+ "Print `args` labeled and readably.
+ Each argument form will be printed, then evaluated and the result printed.
+ One final newline will be printed after everything.
+ Returns the last result.
+ Examples:
+ (let ((i 1)
+ (l (list 1 2 3)))
+ (prl i (second l)))
+ ; =>
+ i 1
+ (second l) 2
+ "
+ `(prog1
+ (progn ,@(mapcar (lambda (arg) `(pr ',arg ,arg)) args))
+ (terpri)
+ (finish-output)))
+(defmacro shut-up (&body body)
+ "Run `body` with stdout and stderr redirected to the void."
+ `(let ((*standard-output* (make-broadcast-stream))
+ (*error-output* (make-broadcast-stream)))
+ ,@body))
+(defmacro comment (&body body)
+ "Do nothing with a bunch of forms.
+ Handy for block-commenting multiple expressions.
+ "
+ (declare (ignore body))
+ nil)
+Pretty-print a table.
+ +Didn’t test.
+ +See also https://github.com/vindarel/cl-ansi-term
+ + + +(defun print-table (rows)
+ ;; https://github.com/sjl/cl-losh/blob/master/losh.lisp#L2334
+ "Print `rows` as a nicely-formatted table.
+ Each row should have the same number of colums.
+ Columns will be justified properly to fit the longest item in each one.
+ Example:
+ (print-table '((1 :red something)
+ (2 :green more)))
+ =>
+ 1 | RED | SOMETHING
+ 2 | GREEN | MORE
+ "
+ (when rows
+ (iterate
+ (with column-sizes =
+ (reduce (alexandria:curry #'mapcar #'max)
+ (mapcar (alexandria:curry #'mapcar (compose #'length #'aesthetic-string))
+ rows))) ; lol
+ (for row :in rows)
+ (format t "~{~vA~^ | ~}~%" (weave column-sizes row))))
+ (values))
+
+
+;; from Quickutil.
+(defun ensure-function (function-designator)
+ "Returns the function designated by `function-designator`:
+if `function-designator` is a function, it is returned, otherwise
+it must be a function name and its `fdefinition` is returned."
+ (if (functionp function-designator)
+ function-designator
+ (fdefinition function-designator)))
+
+;; from Quickutil.
+(defun compose (function &rest more-functions)
+ "Returns a function composed of `function` and `more-functions` that applies its ;
+arguments to to each in turn, starting from the rightmost of `more-functions`,
+and then calling the next one with the primary value of the last."
+ (declare (optimize (speed 3) (safety 1) (debug 1)))
+ (reduce (lambda (f g)
+ (let ((f (ensure-function f))
+ (g (ensure-function g)))
+ (lambda (&rest arguments)
+ (declare (dynamic-extent arguments))
+ (funcall f (apply g arguments)))))
+ more-functions
+ :initial-value function))
+
+(defun make-gensym-list (length &optional (x "G"))
+ "Returns a list of `length` gensyms, each generated as if with a call to `make-gensym`,
+using the second (optional, defaulting to `\"G\"`) argument."
+ (let ((g (if (typep x '(integer 0)) x (string x))))
+ (loop repeat length
+ collect (gensym g))))
+
+ (define-compiler-macro compose (function &rest more-functions)
+ (labels ((compose-1 (funs)
+ (if (cdr funs)
+ `(funcall ,(car funs) ,(compose-1 (cdr funs)))
+ `(apply ,(car funs) arguments))))
+ (let* ((args (cons function more-functions))
+ (funs (make-gensym-list (length args) "COMPOSE")))
+ `(let ,(loop for f in funs for arg in args
+ collect `(,f (ensure-function ,arg)))
+ (declare (optimize (speed 3) (safety 1) (debug 1)))
+ (lambda (&rest arguments)
+ (declare (dynamic-extent arguments))
+ ,(compose-1 funs))))))
+
+
+;; from Quickutil.
+(defun weave (&rest lists)
+ "Return a list whose elements alternate between each of the lists
+`lists`. Weaving stops when any of the lists has been exhausted."
+ (apply #'mapcan #'list lists))
+
+(defun aesthetic-string (thing)
+ "Return the string used to represent `thing` when printing aesthetically."
+ (format nil "~A" thing))
+
+Pretty print a hash-table:
+ +(defun print-hash-table (hash-table &optional (stream t))
+ "Print a pretty representation of `hash-table` to `stream.`
+ Respects `*print-length*` when printing the elements.
+ "
+ (let* ((keys (alexandria:hash-table-keys hash-table))
+ (vals (alexandria:hash-table-values hash-table))
+ (count (hash-table-count hash-table))
+ (key-width (-<> keys
+ (mapcar (alexandria:compose #'length #'prin1-to-string) <>)
+ (reduce #'max <> :initial-value 0)
+ (clamp 0 20 <>))))
+ (print-unreadable-object (hash-table stream :type t)
+ (princ
+ ;; Something shits the bed and output gets jumbled (in SBCL at least) if
+ ;; we try to print to `stream` directly in the format statement inside
+ ;; `print-unreadable-object`, so instead we can just render to a string
+ ;; and `princ` that.
+ (format nil ":test ~A :count ~D {~%~{~{ ~vs ~s~}~%~}}"
+ (hash-table-test hash-table)
+ count
+ (loop
+ :with limit = (or *print-length* 40)
+ :for key :in keys
+ :for val :in vals
+ :for i :from 0 :to limit
+ :collect
+ (if (= i limit)
+ (list key-width :too-many-items (list (- count i) :more))
+ (list key-width key val))))
+ stream)))
+ (terpri stream)
+ (values))
+
+(defun pht (hash-table &optional (stream t))
+ "Synonym for `print-hash-table` for less typing at the REPL."
+ (print-hash-table hash-table stream))
+
+(defun print-hash-table-concisely (hash-table &optional (stream t))
+ "Print a concise representation of `hash-table` to `stream.`
+ Should respect `*print-length*` when printing the elements.
+ "
+ (print-unreadable-object (hash-table stream :type t)
+ (prin1 (hash-table-test hash-table))
+ (write-char #\space stream)
+ (prin1 (hash-table-contents hash-table) stream)))
+
+;; needed:
+(defun clamp (from to value)
+ "Clamp `value` between `from` and `to`."
+ (let ((max (max from to))
+ (min (min from to)))
+ (cond
+ ((> value max) max)
+ ((< value min) min)
+ (t value))))
+
+;; see
+(defmacro -<> (expr &rest forms)
+ "Thread the given forms, with `<>` as a placeholder."
+ ;; I am going to lose my fucking mind if I have to program lisp without
+ ;; a threading macro, but I don't want to add another dep to this library, so
+ ;; here we are.
+ `(let* ((<> ,expr)
+ ,@(mapcar (lambda (form)
+ (if (symbolp form)
+ `(<> (,form <>))
+ `(<> ,form)))
+ forms))
+ <>))
+
+For the -<> threading macro, see cl-arrows and arrow-macros.
Profiling (with SBCL)
+ +#+sbcl
+(defun dump-profile (filename)
+ (with-open-file (*standard-output* filename
+ :direction :output
+ :if-exists :supersede)
+ (sb-sprof:report :type :graph
+ :sort-by :cumulative-samples
+ :sort-order :ascending)
+ (sb-sprof:report :type :flat
+ :min-percent 0.5)))
+
+#+sbcl
+(defun start-profiling (&key call-count-packages (mode :cpu))
+ "Start profiling performance. SBCL only.
+ `call-count-packages` should be a list of package designators. Functions in
+ these packages will have their call counts recorded via
+ `sb-sprof::profile-call-counts`.
+ "
+ (sb-sprof::reset)
+ (-<> call-count-packages
+ (mapcar #'mkstr <>)
+ (mapcar #'string-upcase <>)
+ (mapc #'sb-sprof::profile-call-counts <>))
+ (sb-sprof::start-profiling :max-samples 50000
+ :mode mode
+ ; :mode :time
+ :sample-interval 0.01
+ :threads :all))
+
+#+sbcl
+(defun stop-profiling (&optional (filename "lisp.prof"))
+ "Stop profiling performance and dump a report to `filename`. SBCL only."
+ (sb-sprof::stop-profiling)
+ (dump-profile filename))
+
+#+sbcl
+(defmacro profile (&body body)
+ "Profile `body` and dump the report to `lisp.prof`."
+ `(progn
+ (start-profiling)
+ (unwind-protect
+ (time (progn ,@body))
+ (stop-profiling))))
+
+
+ (bookmark) Get a list of all the dependencies of a lisp system
+Lisp journey 23 01 2018
+I’ll save here +a reddit discussion, +which I find interesting but that will be burried quickly down +reddit’s history. The goal is to get all the dependencies of a +system.
+ +You’d better read the OP’s question and the discussion (where the OP +is the experimented svetlyak40wt/40ants, +at the moment doing a god’s work on Weblocks).
+ +His solution is https://gist.github.com/svetlyak40wt/03bc68c820bb3e45bc7871870379c42e
+ +(ql:quickload :fset)
+
+(defun get-dependencies (system)
+ "Returns a set with all dependencies of a given system.
+ System should be loaded first."
+ (labels ((normalize (name)
+ (etypecase name
+ (string (string-downcase name))
+ (symbol (normalize (symbol-name name)))
+ (list
+ (let ((dep-type (first name))
+ (supported-dep-types (list :version :feature :require)))
+ (unless (member dep-type
+ supported-dep-types)
+ (error "This component \"~A\" should have first element from this list: ~A."
+ name
+ supported-dep-types))
+
+ (normalize
+ (case dep-type
+ (:version (second name))
+ (:feature (third name))
+ (:require (second name)))))))))
+
+ (let ((processed (fset:set))
+ (queue (fset:set (normalize system))))
+
+ (do ((current-name (fset:arb queue)
+ (fset:arb queue)))
+ ((null current-name)
+ ;; return result
+ processed)
+
+ ;; Remove current name from the queue
+ (setf queue
+ (fset:less queue current-name))
+ ;; And put it into the "processed" pool
+ (setf processed
+ (fset:with processed current-name))
+
+ ;; And add it's dependencies which aren't processed or in the queue already
+ ;; Sometimes system can't be found because itself depends on some feature,
+ ;; for example, you can specify dependency as a list:
+ ;; (:FEATURE :SBCL (:REQUIRE :SB-INTROSPECT))
+ ;; and it will be loaded only on SBCL.
+ ;; When we are collecting dependencies on another implementation,
+ ;; we don't want to fail with an error because ASDF is unable to find
+ ;; such dependencies
+ (let* ((system (ignore-errors
+ (asdf:find-system current-name)))
+ (deps (when system
+ (asdf:component-sideway-dependencies system))))
+ (dolist (dep deps)
+ (let ((normalized-dep (normalize dep)))
+ (unless (or (fset:lookup processed normalized-dep)
+ (fset:lookup queue normalized-dep))
+ (setf queue
+ (fset:with queue normalized-dep)))))))
+
+ (values processed))))
+
+#|
+DEPENDENCIES> (ql:quickload :clinch)
+DEPENDENCIES> (get-dependencies :clinch)
+#{
+ "cffi"
+ "sdl2"
+ "uiop"
+ "babel"
+ "swank"
+ "clinch"
+ "cl-glut"
+ "cl-json"
+ "cl-ppcre"
+ "rtg-math"
+ "cl-opengl"
+ "cl-plus-c"
+ "alexandria"
+ "cl-autowrap"
+ "glsl-symbols"
+ "defpackage-plus"
+ "trivial-garbage"
+ "trivial-timeout"
+ "bordeaux-threads"
+ "trivial-channels"
+ "trivial-features" }
+|#
+There’s also (ql-dist:dependency-tree "mgl") which has limitations
+though, it’s only for Quicklisp projects and doesn’t work with
+everything (see the thread).
That’s all folks !
+ +
+ 
+
+
+ Agile Conspiracy
+MonkeyUser 23 01 2018
+
+
+ Print licences used by a given project and its dependencies
+Lisp journey 22 01 2018
+print-licenses is a little utility found in +Steve Losh’s gigantic utilities +and ported to a stand alone project.
+ +Example usage:
+ + (print-licenses 'fast-io)
+ =>
+ alexandria | Public Domain / 0-clause MIT
+ babel | MIT
+ cffi | MIT
+ cffi-grovel | MIT
+ cffi-toolchain | MIT
+ fast-io | NewBSD
+ static-vectors | MIT
+ trivial-features | MIT
+ trivial-gray-streams | MIT
+ uiop | Unspecified
+It may be available on february, 2018 Quicklisp update (request).
+ +One potential source of caution (feedback on reddit):
+ +++ +what many authors put as the license in their asd file is not the license file that is actually included in the source code.
+
+ +
Let’s read the source, there are many useful bits. The core of the job is:
+ +(defun print-licenses (quicklisp-project-designator)
+ (print-table (sort (license-list quicklisp-project-designator)
+ #'string<
+ :key #'car)))
+
+(defun license-list (quicklisp-project-designator)
+ (remove-duplicates
+ (mapcar (alexandria:rcurry #'coerce 'list)
+ (alexandria:flatten (license-tree quicklisp-project-designator)))
+ :key #'car :test #'string=))
+
+(defun license-tree (quicklisp-project-designator)
+ (let ((sys (ql-dist:dependency-tree quicklisp-project-designator)))
+ (assert (not (null sys)) ()
+ "Cannot find Quicklisp project for designator ~S"
+ quicklisp-project-designator)
+ (shut-up
+ (ql:quickload quicklisp-project-designator))
+ (map-tree
+ (lambda (s)
+ (vector (slot-value s 'ql-dist:name)
+ (or (asdf:system-license
+ (asdf:find-system
+ (ql-dist:system-file-name s)))
+ "Unspecified")))
+ sys)))
+
+and those are the remaining building blocks, with a useful
+print-table function, and three of them taken from
+Quickutil. See their website and how sjl does
+to include them (and only them, to keep lightweight dependencies) in a
+project without copy-pasting.
(defmacro shut-up (&body body)
+ "Run `body` with stdout and stderr redirected to the void."
+ `(let ((*standard-output* (make-broadcast-stream))
+ (*error-output* (make-broadcast-stream)))
+ ,@body))
+
+;; from Quickutil.
+(defun map-tree (function tree)
+ "Map `function` to each of the leave of `tree`."
+ (check-type tree cons)
+ (labels ((rec (tree)
+ (cond
+ ((null tree) nil)
+ ((atom tree) (funcall function tree))
+ ((consp tree)
+ (cons (rec (car tree))
+ (rec (cdr tree)))))))
+ (rec tree)))
+
+;; from Quickutil
+(defun aesthetic-string (thing)
+ "Return the string used to represent `thing` when printing aesthetically."
+ (format nil "~A" thing))
+
+;; from Quickutil
+(defun weave (&rest lists)
+ "Return a list whose elements alternate between each of the lists
+`lists`. Weaving stops when any of the lists has been exhausted."
+ (apply #'mapcan #'list lists))
+
+(defun print-table (rows)
+ "Print `rows` as a nicely-formatted table.
+ Each row should have the same number of colums.
+ Columns will be justified properly to fit the longest item in each one.
+ Example:
+ (print-table '((1 :red something)
+ (2 :green more)))
+ =>
+ 1 | RED | SOMETHING
+ 2 | GREEN | MORE
+ "
+ (when rows
+ (iterate
+ (with column-sizes =
+ (reduce (curry #'mapcar #'max)
+ (mapcar (curry #'mapcar (compose #'length #'aesthetic-string))
+ rows))) ; lol
+ (for row :in rows)
+ (format t "~{~vA~^ | ~}~%" (weave column-sizes row))))
+ (values))
+
+ 
+
+
+ Release day
+MonkeyUser 16 01 2018
+
+
+ Generic, consistent and dotted access of data structures with Access
+Lisp journey 12 01 2018
+A common frustration for (impatient) beginners is to see different +function names to access common data structures (alists, plists, +hash-tables) and their inconsistencies (the order of arguments).
+ +Now they are well documented in the… Common Lisp Coobook of course: +https://lispcookbook.github.io/cl-cookbook/data-structures.html, but +still;
+ +and it is annoying to try things out with a data structure and +refactor the code to use another one.
+ +The library Access +solves those problems, it’s always
+ +(access my-var elt)
+(if you’re into this, note that CL21 also does this with a generic and extensible getf).
edit: also rutils with generic-elt or ? in the rutilsx contrib package.
Access also solves another usecase.
+ +Sometimes we deal with nested data structures (alist inside alist
+inside alist, or mixed data structures, happens when working with an
+API) and, as in other languages, we’d like a shortcut to access a
+nested element. In Python, we can use addict to write
+foo.one.2.three instead of foo['one'][2]['three'], with Access we
+have two possibilities, see below.
Oh, and we can be confident it is a battle-tested library, since it +is the one that powers Djula’s +template variables interplolation (doc is +here), where we can write
+ +{{ var.foo }}
+à la Django for the supported data structures, and Djula is in the top 100 of the most downloaded Quicklisp libraries (december 2017 stats).
+ +Let’s install it:
+ +(ql:quickload "access")
+import its symbols in Slime:
+ +(use-package :access)
+Generic and consistent access accross alists, plists, hash-tables, CLOS slots
+ +Let’s create our test variables first:
+ +(defparameter my-alist '((:foo . "foo") (:bar . "bar")))
+MY-ALIST
+(defparameter my-plist (list :foo "foo" :bar "bar"))
+MY-PLIST
+(defparameter my-hashtable (make-hash-table))
+MY-HASHTABLE
+(setf (gethash :foo my-hashtable) "foo")
+"foo"
+(defclass obj-test ()
+ ((foo :accessor foo :initarg :foo :initform :foo)
+ (bar :accessor bar :initarg :bar :initform :bar)))
+;; #<STANDARD-CLASS OBJ-TEST>
+(defparameter my-obj (make-instance 'obj-test))
+;; MY-OBJ
+Now, let’s access the :foo slot.
With alists:
+ +(access my-alist :foo)
+"foo"
+T
+instead of (cdr (assoc :foo my-alist)) (with :foo first argument) or alexandria’s (assoc-value my-alist :foo) (:foo second argument).
plists:
+ +(access my-plist :foo)
+"foo"
+T
+instead of (getf my-plist :foo) (unlike alists, with :foo as last argument).
hash-tables:
+ +(access my-hashtable :foo)
+"foo"
+T
+instead of (gethash :foo my-hashtable) (:foo first argument).
objects:
+ +(access my-obj :foo) ;; <= accessor, not slot name
+;; :FOO
+;; T
+instead of… it depends. Here we named the accessor foo, so we would have used simply (foo my-obj).
Also note that access returns two values, the value and a boolean, t
+if the slot exists, nil otherwise.
And access is setfable:
(setf (access my-alist :foo) "oof")
+with-access
+ +Below, we can bind temporary variables inside with-access:
(with-access (foo bar (other-name plist))
+ my-obj
+ (format t "Got: ~a~a~a~&" foo bar other-name)
+ ;; we can change variables
+ (setf other-name "hello plist")
+ (format t "other-name: ~a~&" other-name)
+ ;; it changed the object too
+ (format t "object slot: ~a~&" (plist my-obj)))
+Got: FOOBAR(FOO foo BAR bar)
+other-name: hello plist
+object slot: hello plist
+NIL
+Nested access
+ +For this example we add a plist slot to our object, which copies our my-plist by default.
(defclass obj-test ()
+ ((foo :accessor foo :initarg :foo :initform :foo)
+ (bar :accessor bar :initarg :bar :initform :bar)
+ (plist :accessor plist :initarg plist :initform (copy-list MY-PLIST))))
+#<STANDARD-CLASS OBJ-TEST>
+(as being a CLOS object, my-obj is automatically updated with the new slot).
We can access the nested plist element :foo inside the object in one go with accesses (plurial):
(accesses MY-OBJ 'plist :foo)
+;; "foo"
+instead of (getf (plist my-obj) :foo).
Dotted access
+ +with-dot or #D
We can rewrite the previous examples with a dot:
+ +(with-dot ()
+ my-alist.foo)
+"foo"
+or again
+ +(with-dot ()
+ my-obj.foo)
+"hello plist"
+but even shorter, with the #D reader macro that we enable with
(enable-dot-syntax)
+(also works in Slime/Sly, for what I am not sure if I enabled a special feature)
+ +#Dmy-alist.foo
+"foo"
+and so, a nested dotted access through an object and a plist:
+ +;; back to initial case
+(setf my-obj (make-instance 'obj-test))
+;; #<OBJ-TEST {1005AA3B13}>
+#Dmy-obj.plist.foo
+;; "foo"
+It will return nil instead of an error if someone in the middle
+doesn’t have the requested field.
+ +
Usage will tell how it is useful, and +I hope it will be to fellow newcomers.
+ +
+
+ Capturing ClojureScript Errors on the Server
+(iterate think thoughts) 12 01 2018
+Logging errors is an important aspect of writing real-world applications. When something goes wrong at runtime it's very helpful to have a log detailing what went wrong in order to fix the problem. This is a straightforward process when we're working on the backend code. We can catch the exception and log it along with the stack trace. However, we need to get a bit more creative in order to handle client-side errors.
In this post we'll take a look at propagating errors from a Reagent based app back to the server. A naive implementation might look something like the following. We'll write a function that accepts an event containing the error, then send the error message along with the stack trace to the server:
(defn report-error! [event]
+ (let [error (.-error event)
+ message (.-message error)
+ stacktrace (.-stack error)]
+ (ajax/POST "/error"
+ {:headers
+ {"x-csrf-token"
+ (.-value (js/document.getElementById "__anti-forgery-token"))}
+ :params
+ {:message message
+ :stacktrace stacktrace}})))
+Next, we'll set the report-error! function as the global error event listener:
(defn init! []
+ (.addEventListener js/window "error" report-error!)
+ (reagent/render [home-page] (.getElementById js/document "app")))
+The home-page function will render a button that will throw an error when it's clicked:
(defn home-page []
+ [:div>h2 "Error Test"
+ [:div>button
+ {:on-click #(throw (js/Error. "I'm an error"))}
+ "throw an error"]])
+If we pop up the console in the browser we should see something like the following there:
Uncaught Error: I'm an error
+ at app.core.home_page (core.cljs:25)
+ at Object.ReactErrorUtils.invokeGuardedCallback (react-dom.inc.js:9073)
+ at executeDispatch (react-dom.inc.js:3031)
+ at Object.executeDispatchesInOrder (react-dom.inc.js:3054)
+ at executeDispatchesAndRelease (react-dom.inc.js:2456)
+ at executeDispatchesAndReleaseTopLevel (react-dom.inc.js:2467)
+ at Array.forEach (<anonymous>)
+ at forEachAccumulated (react-dom.inc.js:15515)
+ at Object.processEventQueue (react-dom.inc.js:2670)
+ at runEventQueueInBatch (react-dom.inc.js:9097)
+This gives us the namespace and the line number in the ClojureScript source that caused the error. However, if we print the message that we received on the server it will look as follows:
Error: I'm an error
+ at app.core.home_page (http://localhost:3000/js/out/app/core.js:51:8)
+ at Object.ReactErrorUtils.invokeGuardedCallback (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:9073:16)
+ at executeDispatch (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:3031:21)
+ at Object.executeDispatchesInOrder (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:3054:5)
+ at executeDispatchesAndRelease (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:2456:22)
+ at executeDispatchesAndReleaseTopLevel (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:2467:10)
+ at Array.forEach (<anonymous>)
+ at forEachAccumulated (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:15515:9)
+ at Object.processEventQueue (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:2670:7)
+ at runEventQueueInBatch (http://localhost:3000/js/out/cljsjs/react-dom/development/react-dom.inc.js:9097:18)
+The stack trace is there, but it's no longer source mapped. So we'll know what namespace caused the error, but not the line in question. In order to get a source mapped stack trace we'll have to use a library such as stacktrace.js. Unfortunately, we won't be able to use the new :npm-deps option in the ClojureScript compiler. This works as expected when :optimizations are set to :none, but fails to provide us with the source mapped stack trace in the :advanced mode.
Instead, we'll use the WebJars dependency along with the ring-webjars middleware:
:dependencies
+[...
+ [ring-webjars "0.2.0"]
+ [org.webjars.bower/stacktrace-js "2.0.0"]]
+The middleware uses the /assets/<webjar>/<asset path> pattern to load the resources packaged in WebJars dependencies. Here's how this would look for loading the stacktrace-js resource.
We'll require the middleware:
(ns app.handler
+ (:require
+ ...
+ [ring.middleware.webjars :refer [wrap-webjars]]))
+Wrap the Ring handler with it:
(defn -main []
+ (run-jetty
+ (-> handler
+ (wrap-webjars)
+ (wrap-defaults site-defaults))
+ {:port 3000 :join? false}))
+The stacktrace.min.js file packaged in the org.webjars.bower/stacktrace-js dependency will be available as a resource at the following path /assets/stacktrace-js/dist/stacktrace.min.js:
(defroutes handler
+ (GET "/" []
+ (html5
+ [:head
+ [:meta {:charset "utf-8"}]
+ (anti-forgery-field)]
+ [:body
+ [:div#app]
+ (include-js "/assets/stacktrace-js/dist/stacktrace.min.js"
+ "/js/app.js")]))
+
+ (POST "/error" {:keys [body]}
+ (let [{:keys [message stacktrace]}
+ (-> body
+ (transit/reader :json)
+ (transit/read))]
+ (println "Client error:" message "\n" stacktrace))
+ "ok")
+
+ (resources "/")
+ (not-found "Not Found"))
+Finally, the ClojureScript compiler configuration will look as follows:
{:output-dir "target/cljsbuild/public/js"
+ :output-to "target/cljsbuild/public/js/app.js"
+ :source-map "target/cljsbuild/public/js/app.js.map"
+ :optimizations :advanced
+ :infer-externs true
+ :closure-warnings {:externs-validation :off
+ :non-standard-jsdoc :off}}
+We need to specify the name of the source map file when using the advanced optimization, tell the compiler to infer the externs, and optionally suppress the warnings.
The new version of the report-error! function will look similar to the original, except that we'll now be passing the error to the StackTrace.fromError function. This function returns a promise containing the source mapped stack trace that we'll be sending to the server:
(defn report-error! [event]
+ (let [error (.-error event)]
+ (-> (js/StackTrace.fromError error)
+ (.then
+ (fn [stacktrace]
+ (ajax/POST "/error"
+ {:headers
+ {"x-csrf-token"
+ (.-value (js/document.getElementById "__anti-forgery-token"))}
+ :params
+ {:message (.-message error)
+ :stacktrace (->> stacktrace
+ (mapv #(.toString %))
+ (string/join "\n "))}}))))))
+This time around we should see the source mapped error on the server with all the information that we need:
I'm an error
+ Error()@http://localhost:3000/js/app/core.cljs:27:23
+ mountComponent()@http://localhost:3000/js/app.js:40:5631
+ focusDOMComponent()@http://localhost:3000/js/app.js:38:22373
+ focusDOMComponent()@http://localhost:3000/js/app.js:38:22588
+ focusDOMComponent()@http://localhost:3000/js/app.js:38:18970
+ focusDOMComponent()@http://localhost:3000/js/app.js:38:19096
+ didPutListener()@http://localhost:3000/js/app.js:41:12120
+ focusDOMComponent()@http://localhost:3000/js/app.js:38:20154
+ mountComponent()@http://localhost:3000/js/app.js:40:5880
+We can see that the error occurred on line 27 of the app.core namespace which is indeed where the code that throws the exception resides. The full listing for the example is available on GitHub.
While the example in this post illustrates bare bones exception handling, we can do more interesting things in a real world application. For example, re-frame based application could send the entire state of the re-frame database at the time of the error to the server. This allows us to put the application in the exact state that caused the error when debugging the problem.
+
+
+ React, Redux and JavaScript Architecture
+James Sinclair 08 01 2018
+
+
+ React, Redux and JavaScript Architecture
+Web Development - James Sinclair 08 01 2018
+
+
+
+
+ Making sense of the trackers on Reddit
+WhoTracksMe blog 07 01 2018
+
+
+
+
+ WhoTracks.me January Update
+WhoTracksMe blog 07 01 2018
+
+
+ Git Deps for Clojure
+Clojure News 05 01 2018
+
+
+Clojure was designed to empower developers by enabling them to leverage existing libraries. When Clojure was first released, this manifest itself in strong interop support for Java. Eventually tooling (Leiningen et al) arose around procuring Java libs from the Maven ecosystem, and Clojure, its contribs, and the community also adopted the Maven approach to delivering libraries via artifacts hosted in well known repositories like Maven Central and Clojars.
+
+
+There were many benefits to this, but, like most things in programming, there were attendant costs. Artifact based releases predate the widespread adoption of content-based addressing systems like Git. Without content-based addressing, they depend on conventions of release naming and weak notions like semantic versioning. They also reflect the nature of languages like Java and C that require a build step prior to execution. Most Clojure libraries do not.
+
+
+The modern reality of Clojure development is that (mostly) we use Git, we use centralized Git repos like Github, Bitbucket et al, and code is executable. Producing and consuming artifacts creates a lot of unnecessary friction between creating code and using it. Let’s get rid of it when not needed!
+
+
+Today we’re happy to announce the availability of git deps support in Clojure tools. It leverages the fact that tools.deps does not use the Maven dependency resolver but instead resolves dependencies on its own. This decouples dependency resolution and classpath creation from any single library publishing/procurement mechanism. Git repos become a source of libraries directly.
+
+
+You can now specify git coordinates (in addition to mvn and local) in deps.edn:
+
+
+
+
+{:deps
+ {org.clojure/data.csv {:git/url "https://github.com/clojure/data.csv.git"
+ :sha "e5beccad0bafdb8e78f19cba481d4ecef5fabf36"}}}
+
+The tools support (available as a library in tools.gitlibs) will:
+
+
+-
+
-
+
securely log into the git repository host and clone the repo (if needed)
+
+ -
+
checkout and cache (per library+sha) the specified working tree (if needed)
+
+ -
+
resolve transitive deps and incorporate the cached directory into the classpath
+
+
+
+Of course, not every commit is stable, so one can designate stable points using tags.
+
+
+This greatly reduces the ceremony and tooling required to share and consume libraries, facilitates parallel development of sibling libraries, testing, speculative forks etc. and fosters a greater connection to source truth while preserving the secure centralized hosting, stable repeatability and caching one gets from e.g. Maven.
+
+
+I am hopeful this git support will usher in a new level of agility for Clojure development. Many thanks to Alex Miller for his tireless efforts to convert these ideas into a working system.
+
+
+For more information see:
+
+
+
+ -
+
-
+
Getting Started - to install or update the Clojure tools
+
+ -
+
Deps and CLI Guide - on how to use the Clojure tools
+
+ -
+
Deps and CLI Reference - complete reference info
+
+ -
+
Spec-ulation keynote - on growth versus breakage
+
+
+
+ Structures: lightweight records, a step before classes
+Lisp journey 03 01 2018
+Structures offer a way to store data in named slots. They support +single inheritance.
+ +Classes provided by the Common Lisp Object System (CLOS) are more flexible however structures may offer better performance (see for example the SBCL manual).
+ +As usual, this is best read in the Common Lisp Cookbook.
+ +Structures
+ +Creation
+ +defstruct
(defstruct person
+ id name age)
+At creation slots are optional and default to nil.
To set a default value:
+ +(defstruct person
+ id
+ (name "john doe")
+ age)
+Also specify the type after the default value:
+ +(defstruct person
+ id
+ (name "john doe" :type string)
+ age)
+We create an instance with the generated constructor make- +
+<structure-name>, so make-person:
(defparameter *me* (make-person))
+*me*
+#S(PERSON :ID NIL :NAME "john doe" :AGE NIL)
+note that printed representations can be read back by the reader.
+ +With a bad name type:
+ +(defparameter *bad-name* (make-person :name 123))
+Invalid initialization argument:
+ :NAME
+in call for class #<STRUCTURE-CLASS PERSON>.
+ [Condition of type SB-PCL::INITARG-ERROR]
+We can set the structure’s constructor so as to create the structure +without using keyword arguments, which can be more convenient +sometimes. We give it a name and the order of the arguments:
+ +(defstruct (person (:constructor create-person (id name age)))
+ id
+ name
+ age)
+Our new constructor is create-person:
(create-person 1 "me" 7)
+#S(PERSON :ID 1 :NAME "me" :AGE 7)
+However, the default make-person does not work any more:
(make-person :name "me")
+;; debugger:
+obsolete structure error for a structure of type PERSON
+[Condition of type SB-PCL::OBSOLETE-STRUCTURE]
+Slot access
+ +We access the slots with accessors created by <name-of-the-struct>- + slot-name:
(person-name *me*)
+;; "john doe"
+we then also have person-age and person-id.
Setting
+ +Slots are setf-able:
(setf (person-name *me*) "Cookbook author")
+(person-name *me*)
+;; "Cookbook author"
+Predicate
+ +(person-p *me*)
+T
+Single inheritance
+ +With the :include <struct> argument:
(defstruct (female (:include person))
+ (gender "female" :type string))
+(make-female :name "Lilie")
+;; #S(FEMALE :ID NIL :NAME "Lilie" :AGE NIL :GENDER "female")
+Limitations
+ +After a change, instances are not updated.
+ +If we try to add a slot (email below), we have the choice to lose
+all instances, or to continue using the new definition of
+person. But the effects of redefining a structure are undefined by
+the standard, so it is best to re-compile and re-run the changed
+code.
(defstruct person
+ id
+ (name "john doe" :type string)
+ age
+ email)
+
+attempt to redefine the STRUCTURE-OBJECT class PERSON
+incompatibly with the current definition
+ [Condition of type SIMPLE-ERROR]
+
+Restarts:
+ 0: [CONTINUE] Use the new definition of PERSON, invalidating already-loaded code and instances.
+ 1: [RECKLESSLY-CONTINUE] Use the new definition of PERSON as if it were compatible, allowing old accessors to use new instances and allowing new accessors to use old instances.
+ 2: [CLOBBER-IT] (deprecated synonym for RECKLESSLY-CONTINUE)
+ 3: [RETRY] Retry SLIME REPL evaluation request.
+ 4: [*ABORT] Return to SLIME's top level.
+ 5: [ABORT] abort thread (#<THREAD "repl-thread" RUNNING {1002A0FFA3}>)
+If we choose restart 0, to use the new definition, we lose access to *me*:
*me*
+obsolete structure error for a structure of type PERSON
+ [Condition of type SB-PCL::OBSOLETE-STRUCTURE]
+There is also very little introspection. +Portable Common Lisp does not define ways of finding out defined super/sub-structures nor what slots a structure has.
+ +The Common Lisp Object System (which came after into the language) +doesn’t have such limitations. See the CLOS section.
+ +-
+
- structures on the hyperspec +
- David B. Lamkins, “Successful Lisp, How to Undertsand and Use Common Lisp”. +
+ 
+
+
+ Error and condition handling
+Lisp journey 02 01 2018
+Common Lisp has mechanisms for error and condition handling as found +in other languages, and can do more.
+ +What is a condition ?
+ +++ +Just like in languages that support exception handling (Java, C++, +Python, etc.), a condition represents, for the most part, an +“exceptional” situation. However, even more so that those languages, +a condition in Common Lisp can represent a general situation where +some branching in program logic needs to take place, not +necessarily due to some error condition. Due to the highly +interactive nature of Lisp development (the Lisp image in +conjunction with the REPL), this makes perfect sense in a language +like Lisp rather than say, a language like Java or even Python, +which has a very primitive REPL. In most cases, however, we may not +need (or even allow) the interactivity that this system offers +us. Thankfully, the same system works just as well even in +non-interactive mode.
+ + +
Let’s dive into it step by step. More resources are given afterwards.
+ +Now best read in the Common Lisp Cookbook.
+ +Credit: our cl-torrents tutorial.
+ +Note: you can contribute any fix or addition to the Cookbook or this page via git ;)
+ + + +Table of Contents
+ +-
+
- Ignore all errors (and return nil) +
- Catching any condition - handler-case +
- Catching a specific condition + + +
- handler-case VS handler-bind +
- Handling conditions - handler-bind +
- Creating conditions +
- Signaling (throwing) conditions +
- Restarts, interactive choices in the debugger + + +
- Run some code, condition or not (“finally”) +
- Resources +
Ignore all errors (and return nil)
+ +Sometimes you know that a function can fail and you just want to
+ignore it: use ignore-errors:
(ignore-errors
+ (/ 3 0))
+; in: IGNORE-ERRORS (/ 3 0)
+; (/ 3 0)
+;
+; caught STYLE-WARNING:
+; Lisp error during constant folding:
+; arithmetic error DIVISION-BY-ZERO signalled
+; Operation was (/ 3 0).
+;
+; compilation unit finished
+; caught 1 STYLE-WARNING condition
+NIL
+#<DIVISION-BY-ZERO {1008FF5F13}>
+We get a welcome division-by-zero warning but the code runs well and
+it returns two things: nil and the condition that was signaled. We
+could not choose what to return.
Rembember that we can inspect the condition with a right click in Slime.
Catching any condition - handler-case
+ + + +ignore-error is built from handler-case. We can write the previous
+example by catching the general error but now we can return whatever
+we want:
(handler-case (/ 3 0)
+ (error (c)
+ (format t "We caught a condition.~&")
+ (values 0 c)))
+; in: HANDLER-CASE (/ 3 0)
+; (/ 3 0)
+;
+; caught STYLE-WARNING:
+; Lisp error during constant folding:
+; Condition DIVISION-BY-ZERO was signalled.
+;
+; compilation unit finished
+; caught 1 STYLE-WARNING condition
+We caught a condition.
+0
+#<DIVISION-BY-ZERO {1004846AE3}>
+We also returned two values, 0 and the signaled condition.
+ +The general form of handler-case is
(handler-case (code that errors out)
+ (condition-type (the-condition) ;; <-- optional argument
+ (code))
+ (another-condition (the-condition)
+ ...))
+We can also catch all conditions by matching t, like in a cond:
(handler-case
+ (progn
+ (format t "This won't work…~%")
+ (/ 3 0))
+ (t (c)
+ (format t "Got an exception: ~a~%" c)
+ (values 0 c)))
+;; …
+;; This won't work…
+;; Got an exception: arithmetic error DIVISION-BY-ZERO signalled
+;; Operation was (/ 3 0).
+;; 0
+;; #<DIVISION-BY-ZERO {100608F0F3}>
+Catching a specific condition
+ +We can specify what condition to handle:
+ +(handler-case (/ 3 0)
+ (division-by-zero (c)
+ (format t "Caught division by zero: ~a~%" c)))
+;; …
+;; Caught division by zero: arithmetic error DIVISION-BY-ZERO signalled
+;; Operation was (/ 3 0).
+;; NIL
+This workflow is similar to a try/catch as found in other languages, but we can do more.
+ +Ignoring the condition argument
+ +If you don’t access the condition object in your handlers, but you still keep it has an argument for good practice, you’ll see this compiler warning often:
+ +; caught STYLE-WARNING:
+; The variable C is defined but never used.
+To remove it, use a declare call as in:
(handler-case (/ 3 0)
+ (division-by-zero (c)
+ (declare (ignore c))
+ (format t "Caught division by zero~%"))) ;; we don't print "c" here and don't get the warning.
+handler-case VS handler-bind
+ +handler-case is similar to the try/catch forms that we find in
+other languages.
handler-bind (see the next examples), is what to use
+when we need absolute control over what happens when a signal is
+raised. It allows us to use the debugger and restarts, either
+interactively or programmatically.
If some library doesn’t catch all conditions and lets some bubble out
+to us, we can see the restarts (established by restart-case)
+anywhere deep in the stack, including restarts established by other
+libraries whose this library called. And we can see the stack
+trace, with every frame that was called and, in some lisps, even see
+local variables and such. Once we handler-case, we “forget” about
+this, everything is unwound. handler-bind does not rewind the
+stack.
Handling conditions - handler-bind
+ +Here we use handler-bind.
Its general form is:
+ +(handler-bind ((a-condition #'function-to-handle-it)
+ (another-one #'another-function))
+ (code that can...)
+ (...error out))
+So, our simple example:
+ +(handler-bind
+ ((division-by-zero #'(lambda (c) (format t "hello condition~&"))))
+ (/ 3 0))
+This prints some warnings, then it prints our “hello” and still +enters the debugger. If we don’t want to enter the debugger, we have +to define a restart and invoke it.
+ +A real example with the
+unix-opts library, that
+parses command line arguments. It defined some conditions:
+unknown-option, missing-arg and arg-parser-failed, and it is up
+to use to write what to do in these cases.
(handler-bind ((opts:unknown-option #'unknown-option)
+ (opts:missing-arg #'missing-arg)
+ (opts:arg-parser-failed #'arg-parser-failed))
+ (opts:get-opts))
+Our unknown-option function is simple and looks like this:
(defun unknown-option (condition)
+ (format t "~s option is unknown.~%" (opts:option condition))
+ (opts:describe)
+ (exit)) ;; <-- we return to the command line, no debugger.
+it takes the condition as parameter, so we can read information from
+it if needed. Here we get the name of the erronous option with the
+defined reader (opts:option condition) (see below).
Creating conditions
+ +With define-condition, and we can inherit from error or simple-error:
(define-condition my-division-by-zero (error) ())
+It is a regular class, so we can add information into slots. Here, we +add a custom message:
+ +(define-condition my-division-by-zero (error)
+ ((dividend :initarg :dividend
+ :reader dividend)) ;; <= so we'll get the dividend with (dividend condition), as soon as on the next line.
+ ;; the :report is the message into the debugger:
+ (:report (lambda (condition stream) (format stream "You were going to divide ~a by zero.~&" (dividend condition)))))
+The general form looks like a regular class definition:
+ +(define-condition my-condition (condition-it-inherits-from)
+ ;; list of arguments, can be "()".
+ ((message :initarg :message
+ :reader my-condition-message)
+ (second ...))
+ ;; class arguments
+ (:report (lambda (condition stream) (...))) ;; what is printed in the REPL.
+ (:documentation "a string")) ;; good practice ;)
+Now when we throw this condition we must pass it an error message (it
+is a required argument), and read it with error-message (the
+:reader).
What’s in :report will be printed in the REPL.
Let’s try our condition. We define a simple function that checks our +divisor, and signals our condition if it is equal to zero:
+ +(defun my-division (x y)
+ (if (= y 0)
+ (error 'MY-DIVISION-BY-ZERO :dividend x))
+ (/ x y))
+When we use it, we enter the debugger:
+ +(my-division 3 0)
+;;
+;; into the debugger:
+;;
+You were going to divide 3 by zero.
+ [Condition of type MY-DIVISION-BY-ZERO]
+
+Restarts:
+ 0: [RETRY] Retry SLIME REPL evaluation request.
+ 1: [*ABORT] Return to SLIME's top level.
+ 2: [ABORT] abort thread (#<THREAD "repl-thread" RUNNING {1002957FA3}>)
+
+Backtrace:
+ 0: (MY-DIVISION 3 0)
+We can inspect the backtrace, go to the source (v in Slime), etc.
+ +
Here is how unix-opts defines its unknown-option condition:
(define-condition troublesome-option (simple-error)
+ ((option
+ :initarg :option
+ :reader option))
+ (:report (lambda (c s) (format s "troublesome option: ~s" (option c))))
+ (:documentation "Generalization over conditions that have to do with some
+particular option."))
+
+(define-condition unknown-option (troublesome-option)
+ ()
+ (:report (lambda (c s) (format s "unknown option: ~s" (option c))))
+ (:documentation "This condition is thrown when parser encounters
+unknown (not previously defined with `define-opts') option."))
+Signaling (throwing) conditions
+ +We can use error, like we did above. Two ways:
-
+
(error "some text"): signals a condition of typesimple-error
+(error 'my-error :message "We did this and this and it didn't work.")
+
Throwing these conditions will enter the interactive debugger, +where a few options will be presented by default. We can give +more options with restarts, +and we can prevent from entering the debugger by handling the condition and invoking a restart.
+ +Simple example from unix-opts: it adds information into the option slot:
(error 'unknown-option
+ :option opt)
+Restarts, interactive choices in the debugger
+ +Defining restarts
+ +Restarts are the choices we get in the debugger, which always has the
+RETRY and ABORT ones. We can add choices to the top of the list:
(defun division-restarter ()
+ (restart-case (/ 3 0)
+ (return-zero () 0)
+ (divide-by-one () (/ 3 1))))
+By calling this stupid function we get two new choices at the top of the debugger:
+ +
Note: read in lisper.in’s blogpost on csv parsing (see Resources) how +this system was used effectively in production.
+ +But that’s not all, by handling restarts we can start over the +operation as if the error didn’t occur (as seen in the stack).
+ +Calling restarts programmatically
+ +With invoke-restart.
(defun division-and-bind ()
+ (handler-bind
+ ((error (lambda (c)
+ (format t "Got error: ~a~%" c) ;; error-message
+ (format t "and will divide by 1~&")
+ (invoke-restart 'divide-by-one))))
+ (division-restarter)))
+;; (DIVISION-AND-BIND)
+;; Got error: arithmetic error DIVISION-BY-ZERO signalled
+;; and will divide by 1
+;; Operation was (/ 3 0).
+;; 3
+Note that we called the form that contains our restarts
+(division-restarter) and not the function that throws the error.
Using other restarts
+ +find-restart 'name-of-restart will return the most recent bound
+restart with the given name, or nil. We can invoke it with
+invoke-restart.
Prompting the user to enter a new value
+ +Let’s add a restart in our division-restarter to offer the user to
+enter a new dividend, and run the division again.
(defun division-restarter ()
+ (restart-case (/ 3 0)
+ (return-nil () nil)
+ (divide-by-one () (/ 3 1))
+ (choose-another-dividend (new-dividend)
+ :report "Please choose another dividend"
+ :interactive (lambda ()
+ (format t "Enter a new dividend: ")
+ (list (read))) ;; <-- must return a list.
+ (format t "New division: 3/~a = ~a~&" new-dividend (/ 3 new-dividend)))))
+We get prompted in the debugger:
+ +arithmetic error DIVISION-BY-ZERO signalled
+Operation was (/ 3 0).
+ [Condition of type DIVISION-BY-ZERO]
+
+Restarts:
+ 0: [RETURN-NIL] RETURN-NIL
+ 1: [DIVIDE-BY-ONE] DIVIDE-BY-ONE
+ 2: [CHOOSE-ANOTHER-DIVIDEND] Please choose another dividend <-- new
+ 3: [RETRY] Retry SLIME REPL evaluation request.
+ 4: [*ABORT] Return to SLIME's top level.
+ 5: [ABORT] abort thread (#<THREAD "repl-thread" RUNNING {1002A47FA3}>)
+The new choose-another-dividend restart takes an argument for the
+new dividend, that will be fed by the :interactive lambda, which
+reads for user input and must return a list.
We use it like this:
+ +(division-restarter)
+;;
+;; Entered debugger, chose the 2nd restart.
+;;
+Enter a new dividend: 10 <-- got prompted to enter a new value.
+New division: 3/10 = 3/10
+NIL
+In a real situation we might want to call our “restarter” recursively, +to get into the debugger again if we enter a bad value.
+ +Hide and show restarts
+ +Restarts can be hidden. In restart-case, in addition to :report
+and :interactive, they also accept a :test key:
(restart-case
+ (return-zero ()
+ :test (lambda ()
+ (some-test))
+ ...
+Run some code, condition or not (“finally”)
+ +The “finally” part of others try/catch/finally forms is done with unwind-protect.
It is the construct used in “with-” macros, like with-open-file,
+which always closes the file after it.
You’re now more than ready to write some code and to dive into other resources !
+ +Resources
+ +-
+
- Practical Common Lisp: “Beyond Exception Handling: Conditions and Restarts” - the go-to tutorial, more explanations and primitives. +
- Common Lisp Recipes, chap. 12, by E. Weitz +
- language reference +
- lisper.in - example with parsing a csv file and using restarts with success, in a flight travel company. +
- Condition Handling in the Lisp family of languages +
- z0ltan.wordpress.com +
- https://github.com/svetlyak40wt/python-cl-conditions - implementation of the CL conditions system in Python. +
+
+ Scripting. Parsing command line arguments, building self-contained executables.
+Lisp journey 02 01 2018
+Using a program from a REPL is fine and well, but if we want to +distribute our program easily, we’ll want to build an executable.
+ +Lisp implementations differ in their processes, but they all create +self-contained executables, for the architecture they are built on. The +final user doesn’t need to install a Lisp implementation, he can run +the software right away.
+ +Start-up times are near to zero, specially with SBCL and CCL.
+ +Binaries size are large-ish. They include the whole Lisp +including its libraries, the names of all symbols, information about +argument lists to functions, the compiler, the debugger, source code +location information, and more.
+ +Note that we can similarly build self-contained executables for web apps.
+ +Now best read in the Common Lisp Cookbook.
+ + + +Table of Contents
+ +-
+
- Building a self-contained executable + + +
- Parsing command line arguments + + +
- Continuous delivery of executables +
- Credit +
Building a self-contained executable
+ +With SBCL
+ +How to build (self-contained) executables is implementation-specific (see +below Buildapp and Rowsell). With SBCL, as says +its documentation, +it is a matter of:
+ +(sb-ext:save-lisp-and-die #P"path/name-of-executable" :toplevel #'my-app:main-function :executable t)
+sb-ext is an SBCL extension to run external processes. See other
+SBCL extensions
+(many of them are made implementation-portable in other libraries).
:executable t tells to build an executable instead of an
+image. We could build an image to save the state of our current
+Lisp image, to come back working with it later. Specially useful if
+we made a lot of work that is computing intensive.
If you try to run this in Slime, you’ll get an error about threads running:
+ +++ +Cannot save core with multiple threads running.
+
Run the command from a simple SBCL repl.
+ +I suppose your project has Quicklisp dependencies. You must then:
+ +-
+
- ensure Quicklisp is installed and loaded at Lisp startup (you +completed Quicklisp installation) +
loadthe project’s .asd
+- install dependencies +
- build the executable. +
That gives:
+ +(load "my-app.asd")
+(ql:quickload :my-app)
+(sb-ext:save-lisp-and-die #p"my-app-binary" :toplevel #'my-app:main :executable t)
+From the command line, or from a Makefile, use --load and --eval:
build:
+ sbcl --load my-app.asd \
+ --eval '(ql:quickload :my-app)' \
+ --eval "(sb-ext:save-lisp-and-die #p\"my-app\" :toplevel #my-app:main :executable t)"
+With ASDF [updated]
+ +Now that we’seen the basics, we need a portable method. Since its
+version 3.1, ASDF allows to do that. It introduces the make command,
+that reads parameters from the .asd. Add this to your .asd declaration:
:build-operation "program-op" ;; leave as is
+:build-pathname "<binary-name>"
+:entry-point "<my-package:main-function>"
+and call asdf:make :my-package.
So, in a Makefile:
+ +LISP ?= sbcl
+
+build:
+ $(LISP) --load torrents.asd \
+ --eval '(ql:quickload :my-app)' \
+ --eval '(asdf:make :my-app)' \
+ --eval '(quit)'
+With Buildapp or Roswell
+ +We might like a more shell-friendly way to build our executable, +and while we’re at it a portable one, so we would have the same +command to work with various implementations.
+ +Buildapp is a battle-tested +“application for SBCL or CCL that configures and saves an executable +Common Lisp image”.
+ +Example usage:
+ +buildapp --output myapp \
+ --asdf-path . \
+ --asdf-tree ~/quicklisp/dists \
+ --load-system my-app \
+ --entry my-app:main
+Many applications use it (for example,
+pgloader). It is available on
+Debian: apt install buildapp.
Roswell, an implementation manager and much
+more, also has the ros build command, that should work for more
+implementations than Buildapp.
We can also make our app installable with Roswell by a ros install
+my-app. See its documentation
For web apps
+ +We can similarly build a self-contained executable for our web-app. It +would thus contain a web server and would be able to run on the +command line:
+ +$ ./my-web-app
+Hunchentoot server is started.
+Listening on localhost:9003.
+Note that this runs the production webserver, not a development one, +so we can run the binary on our VPS right away and access the app from +outside.
+ +We have one thing to take care of, it is to find and put the thread of
+the running web server on the foreground. In our main function, we
+can do something like this:
(defun main ()
+ (start-app :port 9003) ;; our start-app, for example clack:clack-up
+ ;; let the webserver run.
+ ;; warning: hardcoded "hunchentoot".
+ (handler-case (bt:join-thread (find-if (lambda (th)
+ (search "hunchentoot" (bt:thread-name th)))
+ (bt:all-threads)))
+ ;; Catch a user's C-c
+ (#+sbcl sb-sys:interactive-interrupt
+ #+ccl ccl:interrupt-signal-condition
+ #+clisp system::simple-interrupt-condition
+ #+ecl ext:interactive-interrupt
+ #+allegro excl:interrupt-signal
+ () (progn
+ (format *error-output* "Aborting.~&")
+ (clack:stop *server*)
+ (uiop:quit)))
+ (error (c) (format t "Woops, an unknown error occured:~&~a~&" c))))
+We used the bordeaux-threads library ((ql:quickload
+"bordeaux-threads"), alias bt) and uiop, which is part of ASDF so
+already loaded, in order to exit in a portable way (uiop:quit, with
+an optional return code, instead of sb-ext:quit).
Size and startup times of executables per implementation
+ +SBCL isn’t the only Lisp implementation. +ECL, Embeddable +Common Lisp, transpiles Lisp programs to C. That creates a smaller +executable.
+ +According to +this reddit source, ECL produces indeed the smallest executables of all, +an order of magnituted smaller than SBCL, but with a longer startup time.
+ +CCL’s binaries seem to be as fast as SBCL and nearly half the size.
+ +| program size | implementation | CPU | startup time |
+|--------------+----------------+------+--------------|
+| 28 | /bin/true | 15% | .0004 |
+| 1005 | ecl | 115% | .5093 |
+| 48151 | sbcl | 91% | .0064 |
+| 27054 | ccl | 93% | .0060 |
+| 10162 | clisp | 96% | .0170 |
+| 4901 | ecl.big | 113% | .8223 |
+| 70413 | sbcl.big | 93% | .0073 |
+| 41713 | ccl.big | 95% | .0094 |
+| 19948 | clisp.big | 97% | .0259 |
+Parsing command line arguments
+ +SBCL stores the command line arguments into sb-ext:*posix-argv*.
But that variable name differs from implementations, so we may want a +library to handle the differences for us.
+ +We also want to parse the arguments.
+ +A quick look at the +awesome-cl#scripting +list and we’ll do that with the +unix-opts library.
+ +(ql:quickload "unix-opts")
+We can call it with its opts alias (nickname).
As often work happens in two phases:
+ +-
+
- declaring the options our app accepts, their optional argument, defining their type +(string, integer,…), long and short names, and the required ones, +
- parsing them (and handling missing or malformed parameters). +
Declaring arguments
+ +We define the arguments with opts:define-opts:
(opts:define-opts
+ (:name :help
+ :description "print this help text"
+ :short #\h
+ :long "help")
+ (:name :nb
+ :description "here we want a number argument"
+ :short #\n
+ :long "nb"
+ :arg-parser #'parse-integer) ;; <- takes an argument
+ (:name :info
+ :description "info"
+ :short #\i
+ :long "info"))
+Here parse-integer is a built-in CL function.
Example output on the command line (auto-generated help text):
+ +$ my-app -h
+my-app. Usage:
+
+Available options:
+ -h, --help print this help text
+ -n, --nb ARG here we want a number argument
+ -i, --info info
+Parsing
+ +We parse and get the arguments with opts:get-opts, which returns two
+values: the list of valid options and the remaining free arguments. We
+then must use multiple-value-bind to assign both into variables:
(multiple-value-bind (options free-args)
+ ;; There is no error handling yet.
+ (opts:get-opts)
+ ...
+We can test this by giving a list of strings to get-opts:
(multiple-value-bind (options free-args)
+ (opts:get-opts '("hello" "-h" "-n" "1"))
+ (format t "Options: ~a~&" options)
+ (format t "free args: ~a~&" free-args))
+Options: (HELP T NB-RESULTS 1)
+free args: (hello)
+NIL
+If we put an unknown option, we get into the debugger. We’ll see +error handling in a moment.
+ +So options is a
+property list. We
+use getf and setf with plists, so that’s how we do our
+logic. Below we print the help with opts:describe and then exit
+(in a portable way).
(multiple-value-bind (options free-args)
+ (opts:get-opts)
+
+ (if (getf options :help)
+ (progn
+ (opts:describe
+ :prefix "You're in my-app. Usage:"
+ :args "[keywords]") ;; to replace "ARG" in "--nb ARG"
+ (opts:exit))) ;; <= optional return status.
+ (if (getf options :nb)
+ ...)
+For a full example, see its +official example +and +cl-torrents’ tutorial.
+ +The example in the unix-opts repository suggests a macro to do +slightly better. Now to error handling.
+ +Handling malformed or missing arguments
+ +There are 4 situations that unix-opts doesn’t handle, but signals +conditions for us to take care of:
+ +-
+
- for an unknown argument: an
unknown-optioncondition is signaled
+ - also
missing-arg
+ arg-parser-failedwhen, for example, it expected an integer but got text
+missing-required-option
+
So, we must create simple functions to handle those conditions, and
+surround the parsing of the options with an handler-bind:
(multiple-value-bind (options free-args)
+ (handler-bind ((opts:unknown-option #'unknown-option) ;; the condition / our function
+ (opts:missing-arg #'missing-arg)
+ (opts:arg-parser-failed #'arg-parser-failed)
+ (opts:missing-required-option))
+ (opts:get-opts))
+ …
+ ;; use "options" and "free-args"
+Here we suppose we want one function to handle each case, but it could +be a simple one. They take the condition as argument.
+ +(defun handle-arg-parser-condition (condition)
+ (format t "Problem while parsing option ~s: ~a .~%" (opts:option condition) ;; reader to get the option from the condition.
+ condition)
+ (opts:describe) ;; print help
+ (opts:exit)) ;; portable exit
+For more about condition handling, see error and condition handling.
+ +Catching a C-c termination signal
+ +Let’s build a simple binary, run it, try a C-c and read the stacktrace:
$ ./my-app
+sleep…
+^C
+debugger invoked on a SB-SYS:INTERACTIVE-INTERRUPT in thread <== condition name
+#<THREAD "main thread" RUNNING {1003156A03}>:
+ Interactive interrupt at #x7FFFF6C6C170.
+
+Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.
+
+restarts (invokable by number or by possibly-abbreviated name):
+ 0: [CONTINUE ] Return from SB-UNIX:SIGINT. <== it was a SIGINT indeed
+ 1: [RETRY-REQUEST] Retry the same request.
+The signaled condition is named after our implementation:
+sb-sys:interactive-interrupt. We just have to surround our
+application code with a handler-case:
(handler-case
+ (run-my-app free-args)
+ (sb-sys:interactive-interrupt () (progn
+ (format *error-output* "Abort.~&")
+ (opts:exit))))
+This code only for SBCL though. We know about +trivial-signal, +but we were not satisfied with our test yet. So we can use something +like this:
+ +(handler-case
+ (run-my-app free-args)
+ (#+sbcl sb-sys:interactive-interrupt
+ #+ccl ccl:interrupt-signal-condition
+ #+clisp system::simple-interrupt-condition
+ #+ecl ext:interactive-interrupt
+ #+allegro excl:interrupt-signal
+ ()
+ (opts:exit)))
+here #+ includes the line at compile time depending on
+the implementation. There’s also #-. What #+ does is to look for
+symbols in the *features* list. We can also combine symbols with
+and, or and not.
Continuous delivery of executables
+ +We can make a Continuous Integration system (Travis CI, Gitlab CI,…) +build binaries for us at every commit, or at every tag pushed or at +wichever other policy.
+ + + +Credit
+ + + +
+
+ How to Add a Text Filter to Django Admin
+Haki Benita 01 01 2018
+Django Admin search fields are great, throw a bunch of fields in search_fields and Django will handle the rest. The problem with search field begins when there are too many of them. This is how we replaced Django search with text filters for specific fields, and made Django admin much faster.
+
+
+ Let's hand write DNS messages
+Posts on James Routley 28 12 2017
+
+ 
+
+
+ Santa's Smart Contract
+MonkeyUser 24 12 2017
+
+ 
+
+
+ cl-torrents, app and (extensive) tutorial: web scraping and building executables
+Lisp journey 20 12 2017
+Lately we exercised our Lisp skills by writing +cl-torrents, an app that +searches for torrents on several sources (the Pirate Bay through +piratebay.to, Kickass torrents and torrent.cd), and we wrote an +extensive tutorial +in the making (that was actually our primary goal). It comes as a +library to use from the REPL and as a self-contained executable +(download and run, nothing more to install). You’ll find the following +topics in the tutorial:
+ +-
+
- how to create and load a new project, +
- common pitfalls, basic data structures, useful libraries, where to find documentation, +
- (async) web scraping, +
- unit testing, with mocks, +
- continuous integration and delivery of executables (Gitlab CI, Docker), +
- parsing command line arguments, +
- building self-contained executables, +
- basics of error handling, +
- … +
Some topics have been ported to the Cookbook, some not (yet).
+ +
The next iteration will be about a self-contained web app.
+ +
+ 
+
+
+ (bug)fixing car using
+MonkeyUser 12 12 2017
+
+
+ Django Admin Range-Based Date Hierarchy
+Haki Benita 10 12 2017
+A few weeks ago we encountered a major performance regression in one of our main admin pages. The page took more than 10 seconds to load (at best) and hit the query execution timeout at worst. When we investigated the issue, we found that the date hierarchy was the cause for most of the time spent loading the admin page. In the article we describe how we significantly improved the performance of Django Admin date hierarchy
+
+
+ Clojure 1.9 is now available
+Clojure News 08 12 2017
+
+
+
+
+
+
+Clojure 1.9 is now available!
+
+
+Clojure 1.9 introduces two major new features: integration with spec and command line tools.
+
+
+spec (rationale, guide) is a library for describing the structure of data and functions with support for:
+
+
+-
+
-
+
Validation
+
+ -
+
Error reporting
+
+ -
+
Destructuring
+
+ -
+
Instrumentation
+
+ -
+
Test-data generation
+
+ -
+
Generative test generation
+
+ -
+
Documentation
+
+
+
+Clojure integrates spec via two new libraries (still in alpha):
+
+
+-
+
-
+
spec.alpha - spec implementation
+
+ -
+
core.specs.alpha - specifications for Clojure itself
+
+
+
+This modularization facilitates refinement of spec separate from the Clojure release cycle.
+
+
+The command line tools (getting started, guide, reference) provide:
+
+
+-
+
-
+
Quick and easy install
+
+ -
+
Clojure REPL and runner
+
+ -
+
Use of Maven and local dependencies
+
+ -
+
A functional API for classpath management (tools.deps.alpha)
+
+
+
+The installer is available for Mac developers in brew, for Linux users in a script, and for more platforms in the future.
+
+
+For more information, see the complete list of all changes in Clojure 1.9 for more details.
+
+
+
+ Contributors
+
+
+
+
+Thanks to all of the community members who contributed to Clojure 1.9 (first time contributors in bold):
+
+
+-
+
-
+
Adam Clements
+
+ -
+
Andy Fingerhut
+
+ -
+
Brandon Bloom
+
+ -
+
Cameron Desautels
+
+ -
+
Chad Taylor
+
+ -
+
Chris Houser
+
+ -
+
David Bürgin
+
+ -
+
Eli Lindsey
+
+ -
+
Gerrit Jansen Van Vuuren
+
+ -
+
Ghadi Shayban
+
+ -
+
Greg Leppert
+
+ -
+
Jason Whitlark
+
+ -
+
Johan Mena
+
+ -
+
Jozef Wagner
+
+ -
+
Lee Yen-Chin
+
+ -
+
Matthew Boston
+
+ -
+
Michael Blume
+
+ -
+
Michał Marczyk
+
+ -
+
Nicola Mometto
+
+ -
+
Ruslan Al-Fakikh
+
+ -
+
Steffen Dienst
+
+ -
+
Steve Miner
+
+ -
+
Yegor Timoshenko
+
+ -
+
Zhuang XiaoDan
+
+
+
+
+
+ WhoTracks.me December Update
+WhoTracksMe blog 07 12 2017
+
+
+ Who's using Common Lisp ?
+Lisp journey 05 12 2017
+++ +Everyone says “Nobody uses Lisp” and Lispers say “Yes they do, there’s ITA, and, um, Autocad, and, uh, oh yeah, Paul Graham wrote Viaweb in Lisp!” Not very helpful for either side.
+
Following Lisp Companies blog post (2008, many dead links).
+ +Reddit and lispjobs are the major sources. Sponsors can be found on the European Lisp Symposium website.
+ +Of course, see
+ +-
+
- lisp-lang.org’s success stories for +a showcase of projects and companies in aerospace, AI & Machine +Learning, Science, Graphics etc. +
- franz.com success stories +
- lisp-journey’s short software list (pgloader,…) +
- awesome-cl-software (old and current), +
- awesome-cl libraries. +
- awesome-lisp-companies, a bigger list. +
Let’s quote Kent Pitman’s famous answer:
+ +++ +But please don’t assume this is an exhaustive list, and please don’t assume Lisp is only useful for Animation and Graphics, AI, Bioinformatics, B2B and Ecommerce, Data Mining, EDA/Semiconductor applications, Expert Systems, Finance, Intelligent Agents, Knowledge Management, Mechanical CAD, Modeling and Simulation, Natural Language, Optimization, Research, Risk Analysis, Scheduling, Telecom, and Web Authoring just because these are the only things they happened to list. Common Lisp really is a general language capable of a lot more than these few incidental application areas, even if this web page doesn’t totally bring that out.
+
(and this list doesn’t mention that it was used for auto-piloting the +DS1 spaceship by the NASA for several days)
+ ++ +
-
+
- D-wave systems, “quantum processor development”. “The software is implemented in Common Lisp (SBCL) and is an integral part of the quantum computing system.” lispjobs announce. +
- Emotiq - a next-generation +blockchain with an innovative natural-language approach to smart +contracts. +
- Grammarly, +an English language writing-enhancement platform. +
- m-creations, custom software +solutions for mid-size to big companies in finance/payment, health +care, and media. Using Common Lisp in different fields ranging from +dynamic web applications and Natural Language Processing to systems +engineering infrastructure in container clusters (DNS, dynamic load +balancer). +
- Ravenpack, “the leading big data analytics provider for financial services”. reddit announce. +
- Rigetti, new quantum computing company. They already sponsored a Quicklisp development. They chose Common Lisp (SBCL). Video. Their Lisp even runs 40% faster than their C code. +
- Secure Outcomes “builds and provides digital livescan fingerprinting systems for use by law enforcement, military, airports, schools, Fortune 500s, etc.”. “All of our systems are constructed in Common Lisp.”. lispjobs announce. +
- Somewrite.jp, a “native advertising network platform”. Common Lisp web development. lispjobs announce. A Fukamachi company. press write up. +
- Spycursion PC game. Reddit announce. +
+ 
+
+
+ Compile vs Runtime Error
+MonkeyUser 05 12 2017
+
+ 
+
+
+ Continuous Integration and delivery on Gitlab CI, testing locally with Docker
+Lisp journey 01 12 2017
+Best read in the Cookbook ! also Travis CI, code coverage, testing with Prove.
+ +Gitlab CI is part of
+Gitlab and is available on Gitlab.com, for
+public and private repositories. Let’s see straight away a simple
+.gitlab-ci.yml:
image: daewok/lisp-devel
+
+before_script:
+ - apt-get update -qy
+ - apt-get install -y git-core
+ - git clone https://github.com/foo/bar ~/quicklisp/local-projects/
+
+test:
+ script:
+ - make test
+Gitlab CI is based on Docker. With image we tell it to use the
+daewok/lisp-devel
+one. It includes SBCL, ECL, CCL and ABCL, and Quicklisp is installed
+in the home (/home/lisp/), so we can quickload packages right
+away. If you’re interested it also has a more bare bones option. Gitlab will load the
+image, clone our project and put us at the project root with
+administrative rights to run the rest of the commands.
test is a “job” we define, script is a
+recognized keywords that takes a list of commands to run.
Suppose we must install dependencies before running our tests:
+before_script will run before each job. Here we clone a library
+where Quicklisp can find it, and for doing so we must install git
+(Docker images are usually pretty bare bones).
We can try locally ourselves. If we already installed Docker and
+started its daemon (sudo service docker start), we can do:
docker run --rm -it -v /path/to/local/code:/usr/local/share/common-lisp/source daewok/lisp-devel:latest bash
+This will download the lisp image (±400Mo), mount some local code in
+the image where indicated, and drop us in bash. Now we can try a make
+test.
To show you a more complete example:
+ +image: daewok/lisp-devel
+
+stages:
+ - test
+ - build
+
+before_script:
+ - apt-get update -qy
+ - apt-get install -y git-core
+ - git clone https://github.com/foo/bar ~/quicklisp/local-projects/
+
+test:
+ stage: test
+ script:
+ - make test
+
+build:
+ stage: build
+ only:
+ - tags
+ script:
+ - make build
+ artifacts:
+ paths:
+ - some-file-name
+Here we defined two stages (see
+environments),
+“test” and “build”, defined to run one after another. A “build” stage
+will start only if the “test” one succeesds.
“build” is asked to run only when a
+new tag is pushed, not at every commit. When it succeeds, it will make
+the files listed in artifacts’s paths available for download. We can
+download them from Gitlab’s Pipelines UI, or with an url. This one will download
+the file “some-file-name” from the latest “build” job:
https://gitlab.com/username/project-name/-/jobs/artifacts/master/raw/some-file-name?job=build
+When the pipelines pass, you will see:
+ +
You now have a ready to use Gitlab CI.
+ +
+
+ Using a logbook to improve your programming
+Posts on James Routley 23 11 2017
+
+ 
+
+
+ Specs...
+MonkeyUser 21 11 2017
+
+
+
+
+ Generating Ad-Blocker filters from whotracks.me data
+WhoTracksMe blog 19 11 2017
+
+ 
+
+
+ Step By Step Debugging
+MonkeyUser 14 11 2017
+
+
+ Introducing Clojurists Together
+News on Clojurists Together 13 11 2017
+
+ 
+
+
+ Merging Branches
+MonkeyUser 07 11 2017
+
+
+
+
+ The Impact of Tracking on User Experience
+WhoTracksMe blog 06 11 2017
+
+
+ Intermediate Testing in Golang
+Posts on James Routley 05 11 2017
+
+
+ First impressions of Elm
+Posts on James Routley 31 10 2017
+
+
+ Installing libraries, dependencies management
+Lisp journey 27 10 2017
+Common Lisp may have more libraries than you think. See:
+ +-
+
- Quickdocs - the library documentation hosting for CL. +
- the Awesome-cl list, a +curated list of libraries. +
- lisp-lang.org’s recommended libraries (from State of the CL ecosystem, 2015) +
Quicklisp is the de-facto package manager, but not the only tool.
+ +Some terminology first
+ +-
+
In the Common Lisp world, a package is a way of grouping symbols +together and of providing encapsulation. It is similar to a C++ +namespace, a Python module or a Java package.
+
+A system is a collection of CL source files bundled with an .asd +file which tells how to compile and load them. There is often a +one-to-one relationship between systems and packages, but this is in +no way mandatory. A system may declare a dependency on other +systems. Systems are managed by ASDF (Another System Definition +Facility), which offers functionalities similar to those of make and +ld.so, and has become a de facto standard.
+
+A Common Lisp library or project typically consists of one or +several ASDF systems (and is distributed as one Quicklisp project).
+
Install Quicklisp
+ +Quicklisp is more than a package +manager, it is also a central repository (a dist) that ensures that +all libraries build together. This involves some manual work (like +reporting errors to package authors), so this is why Quicklisp +releases its dist updates once a month (but fear not, we have other +tools).
+ +It provides its own dist but it is also possible to build our own.
+ +To install it, we can either:
+ +1- run this command, anywhere:
+ +curl -O https://beta.quicklisp.org/quicklisp.lisp
+and enter a Lisp REPL and load this file:
+ +sbcl --load quicklisp.lisp
+or
+ +2- install the Debian package:
+ +apt-get install cl-quicklisp
+and load it, from a REPL:
+ +(load "/usr/share/cl-quicklisp/quicklisp.lisp")
+Then, in both cases, still from the REPL:
+ +(quicklisp-quickstart:install)
+This will create the ~/quicklisp/ directory, where Quicklisp will
+maintain its state and downloaded projects.
If you want Quicklisp to always be loaded in your Lisp sessions, run
+(ql:add-to-init-file): this adds the right stuff to the init file of
+your CL implementation. Otherwise, you have to run (load
+"~/quicklisp/setup.lisp") in every session if you want to use
+Quicklisp or any of the libraries installed through it.
It adds the following in your (for example) ~/.sbclrc:
#-quicklisp
+ (let ((quicklisp-init (merge-pathnames "quicklisp/setup.lisp"
+ (user-homedir-pathname))))
+ (when (probe-file quicklisp-init)
+ (load quicklisp-init)))
+Install libraries
+ +In the REPL:
+ +(ql:quickload "package-name")
+and voilà. See Quicklisp’s documentation for more commands.
+ +Note also that dozens of Common Lisp libraries are packaged in
+Debian. The package names usually begin with the cl- prefix (use
+apt-cache search --names-only "^cl-.*" to list them all).
For example, in order to use the CL-PPCRE library (for regular
+expressions), one should first install the cl-ppcre package.
Then, in SBCL and ECL, it can be used with:
+ +(require "asdf")
+(require "cl-ppcre")
+(cl-ppcre:regex-replace "fo+" "foo bar" "frob")
+See more: https://wiki.debian.org/CommonLisp
+ +Advanced dependencies management
+ +Quicklisp installs the libraries into ~/quicklisp/local-projects/. A
+library installed here is automatically available for every project.
Providing our own version of a library. Cloning projects.
+ +Given the property above, we can clone any library into the +local-projects directory and it will be found by quicklisp and +available right-away:
+ +(ql:quickload "package")
+And also given the M-. “go to this symbol definition” feature in
+Slime (and M-, to go back), it’s really easy to not only explore but
+start tweaking and extending other libraries.
How to work with local versions of libraries
+ +If we need libraries to be installed locally, for only one project, or +in order to easily ship a list of dependencies with an application, we +can use Qlot. This is like +Python’s virtual environments.
+ +Quicklisp also provides +Quicklisp bundles. They +are self-contained sets of systems that are exported from Quicklisp +and loadable without involving Quicklisp.
+ +At last, there’s +Quicklisp controller +to help us build dists. Some projects use this, like CL21.
+ +Read more
+ +-
+
- Source code organization, libraries and packages: https://lispmethods.com/libraries.html +
- https://wiki.debian.org/CommonLisp +
See also
+ +-
+
- Qi - a package manager for Common Lisp +
+
+
+
+ Dreaming Sarah: Guía de curiosidades y teorías
+Emezeta blog 27 10 2017
+
+ 
+
+
+ Opinions
+MonkeyUser 24 10 2017
+
+
+ Lisp software
+Lisp journey 19 10 2017
+There’s a fantastic showcase of succesfull Common Lisp software on +lisp-lang.org: http://lisp-lang.org/success/ so go there first.
+ +However all are not open source and it doesn’t list new or not so +awesome but very cool or interesting software. That’s what we’ll do +here to see that yeah Lisp is used today and to have code bases to +look at.
+ +If you are looking for CL libraries, you of course had a look to the +Awesome CL list.
+ +Awesome Lisp software
+ +-
+
- pgloader - re-written from +Python with a 20 to 30x speed gain and more O_o - +blog post +By Dimitri Fontaine working at Postgres in 2014. He also maintains +around 50 Debian packages of Lisp libraries for these needs. He gave +a +lightning talk at the 7th European Lisp Symposium. Uses Postmodern and lparallel for asynchronous IO. Also, +
++ +the new code base and feature set seems to attract way more users than the previous implementation ever did, despite using a less popular programming language.
+
-
+
pgchart - a self-contained web application that takes as input an SQL query text and outputs its data as a chart. By the same Dimitri Fontaine.
+
+potato - a Slack-like conversation platform. Many features. CL in the backend, ClojureScript to the frontend. Apache Solr, RabbitMQ, email updates,… Web, Emacs and Android clients. web coding video.
+
+turtl - a security focused online note taking app. Deployed at scale at Framanotes. Backend in CL.
+
Internet
+ +-
+
- nEXT browser - Qt based web browser. +
- cl-torrents - (my) library, cli and readline app to search for torrents on popular trackers, with an extensive tutorial. +
Publishing software
+ +-
+
- Coleslaw - a static site generator similar to Jekyll. With nifty features (build on git push,…). Example blog: http://40ants.com/ +
- Radiance - publishing software, between CMS and framework. +
- Reader - a simple blogging platform for Radiance. +
- Purplish - an imageboard app for Radiance. +
Editors
+ +-
+
Darkmatter - Common Lisp notebook (also exists cl-jupyter). Built on Clack.
+
+Lem - an Emacs clone tailored for Common Lisp development, for the terminal or Electron. Screencast.
+
GUI apps
+ +-
+
- Halftone - a multiplatform +and portable image viewer. Simple app to demo building Qt GUIs with +Qtools. +
Terminal apps
+ +todo: enhance !
-
+
- Pml - cli tool to parse my nginx logs and print statistics (and Tankfeeder for apache) +
- shuffletron - +a terminal music player. [staling] +
- shtookovina - a program to +help learn natural languages, based on audio recording by the +Shtooka project, with an advanced readline +interface and fully hackable in Common Lisp. Deprecated since 2015. +
+ 
+
+
+ IT Hell
+MonkeyUser 17 10 2017
+
+
+ Advice on starting a programming blog
+Posts on James Routley 15 10 2017
+
+ 
+
+
+ Deadline
+MonkeyUser 10 10 2017
+
+
+ Implementing 'undo' in a text editor
+Posts on James Routley 08 10 2017
+
+
+ Scaling Django Admin Date Hierarchy
+Haki Benita 05 10 2017
+The date hierarchy is a great feature but it comes at a price. On very large tables, the way date hierarchy is implemented can make an admin page nearly unusable. In this article we describe the limitations of the date hierarchy, and suggest a way to overcome them.
+
+
+ Yo conozco mi fauna
+Andanzas de una ambientóloga . . . 04 10 2017
+
+
+ Moving Forward by Letting Go
+(iterate think thoughts) 03 10 2017
+Lisps are famous for having powerful metaprogramming facilities derived from their homoiconic nature. Core language consists of a small set of built in primitives, and the rest is implemented using macros and functions in the standard library.
Since these same tools are available to the users, anybody can easily extend the language to add semantics for their problem domain. This is the aspect of macros that's discussed most often.
While this is certainly the case, Clojure community tends to discourage using macros if they can be avoided. The rationale behind this being that macros introduce additional complexity, and Clojure values simplicity. I generally agree with this sentiment, and I find that I tend to use macros sparingly myself. However, saying that macros shouldn’t be overused is not the same as saying they shouldn’t be used at all.
One place where macros work well is library APIs. Libraries that express a particular domain can create a DSL in their API that cleanly maps to that domain. Compojure, Specter, and Clara Rules are great examples of effective macro use. Such libraries are a powerful demonstration of users extending semantics of the language.
Since most ideas can be expressed via libraries, it becomes possible to experiment with different approaches to solving problems without modifying the core language. Extending the language through libraries has the advantage of keeping these extensions contained. It also lets them fade away when you no longer use them.
Clojure has been around for a decade now, and the core language hasn't changed much in that time. Some new features have been added, most notably reducers and transducers, but overall the language has stayed small and focused. In fact, I've even seen concerns that Clojure is stagnating because features aren't being added at the rate of other languages.
The idea of using libraries to add features is used by the Clojure core team as well. Consider the example of the core.async library that brings Go channel semantics and the CSP programming model to Clojure.
Perhaps, in time a better idea will come along, and core.async library will become deprecated. At that point developers would stop using the library and move on to use whatever happens to replace it.
Meanwhile, existing projects will not be affected as they can continue using the library. The community will move on, and most people won't have to learn about core.async semantics. This cycle may happen many times with many different ideas, without any baggage being accumulate by the language itself.
Unfortunately, mainstream languages are designed in a way where it's not practical to add new features without updating the language specification to accommodate them. Popular languages such as Java, Python, and JavaScript have accumulated a lot of complexity over the years.
As usage patterns change, new features are being added, while existing features become deprecated. Removing features is difficult since many projects in the wild end up relying on them, so they're typically left in place.
Having lots of features in a language can seem like a positive at first glance, but in practice, features often turn into a mental burden for the developer. Eventually languages become too large to understand fully, and developers settle on a subset of the features considered to be the current best practice.
In my opinion, this is the real power of homoiconicity. A language that can be extended in user space can evolve without accumulating baggage. New ideas can be implemented as libraries, and later discarded when better ideas come along. The end result is a small and focused language that doesn't sacrifice flexibility.
+
+ 
+
+
+ Visualized Codebase
+MonkeyUser 03 10 2017
+
+ 
+
+
+ Design Patterns - Bureaucracy
+MonkeyUser 26 09 2017
+
+ 
+
+
+ Instapaper is now optimized for iOS 11
+Instapaper 20 09 2017
+Today we’re launching our iOS 11-tailored update with drag and drop support for iPad and iPad Pro as well as performance improvements for Instapaper across all iOS devices.
+Drop to save
iOS 11 makes saving articles and videos to Instapaper more seamless. To save from another app, first multitask Instapaper using Slide Over or Split View. From there, long-press on a link in another app, such as Safari, and drag it into Instapaper to save it. If you drag a link into an open folder, it will save directly to that folder.
Drag into other apps
+
It’s now easier to share articles from your Instapaper account to other apps. Just long-press on an article entry and drop it into a compatible app, like Mail or a browser. Dragging from Instapaper also works from search results, so it’s simple to find and share anything in your account, regardless of whether it’s synced to your device. Article highlights and notes can be shared by dragging from the Notes section.
iOS 11 Password AutoFill
We added support for iOS 11’s new Password AutoFill feature. If your Instapaper credentials are stored in your iCloud Keychain, you’ll now see the option to use your saved password above the keyboard when logging in on iOS.
Bug fixes
This update addresses a variety of user-reported issues from the last release. We’ve improved our handling of embedded video content, particularly for poor connection scenarios, to ensure better and faster opening of saves in all conditions.
We also fixed a recent issue where exiting an article with a swipe gesture could result in your current reading position not saving.
Lastly, we made several search UI improvements, including a fix for a small line that would occasionally appear across the search tab.
We hope these updates make reading, sharing and multitasking with Instapaper better than ever.
If you’ve got any questions or feedback, just let us know via support@help.instapaper.com or @InstapaperHelp on Twitter.
+
+ 
+
+
+ Web App - Visualized
+MonkeyUser 19 09 2017
+
+ 
+
+
+ Productive Scrum Meetings
+MonkeyUser 12 09 2017
+
+
+ RITA LEVI-MONTALCINI
+Andanzas de una ambientóloga . . . 09 09 2017
+
+
+ Volvemos!!! Septiembre mi mes favorito
+Andanzas de una ambientóloga . . . 03 09 2017
+
+
+ Gap Buffers: a data structure for editable text
+Posts on James Routley 01 09 2017
+
+
+ Why do we have to wait one month for Quicklisp updates ?
+Lisp journey 31 08 2017
+If you didn’t know that, now you do. Quicklisp releases software +updates once a month (see +Quicklisp’s blog). I didn’t know why, it +isn’t explained on its website, so I asked +(issue #148). I +found the discussion very insightful, everybody being constructive, +existing solutions being discussed and architectural choices +explained. But it ended up brutally with one more Common Lisp oddity.
+ +My first impression was that this fact is annoying, because it already +prevented me a couple of times to use my own library and its most +recent updates into other projects. They would pull the lib from +Quicklisp but wouldn’t benefit from its latest features.
+ +This way of doing was also not the package management model I was most +used to (pip, npm,…), but by wording things differently it makes more +sense to me. As an user says:
+ +++ +I think it is a very unique to quicklisp, making sure that everything compiles together. I can’t think of any other libraries/frameworks system on other languages/platforms that would go as far. Really great work.
+
So Quicklisp is more than a package manager, it is a “dist” builder +ensuring everything works together, closer to apt than to pip.
+ +The situation and shortcomings is well described by axity on +his blog post (now showing a +404):
+ +++ +Zach Beane has done an excellent job with Quicklisp, and it is far better than what we previously had available, but still has a few problems. Zach puts a lot of effort into curating a list of compatible software together into the form of a “Quicklisp dist” rolled out approximately every month. While this is great and puts near-zero maintenance on developers, it poses a few problems.
+ +Firstly, Zach is a single point of failure. Yes, anyone can maintain their very own Quicklisp dist, but it isn’t going to see the masses, and the Quicklisp internals are not very well understood by anyone other than Zach.
+ +Also the fact that the official dists are rolled out so far apart (a month or longer in the software world is an eternity), means developers cannot push hot-fixes or address user-reported bugs in a timely manner, without pushing maintenance onto the users by having them checkout upstream sources.
+ +Modern languages such as Julia and Racket offer central repositories where a developer can register their software projects, and will be automatically indexed periodically, so that users can continue to install and update software without any maintenance, and still receive updates quickly when needed. Additionally, they push managing version dependencies onto the developer, which I do not believe to be a bad thing. In contrast, Common Lisp libraries are rarely versioned, and all of that maintenance is forced upon the Quicklisp dist curator.
+
I also like /u/ruricolist’s explanations +(on reddit):
+ +++ +Quicklisp provides more assurance than you might expect. The criterion for inclusion, and maintenance, of a project in Quicklisp is that the project successfully load in SBCL alongside all the libraries in that Quicklisp distribution, and load without any errors or warnings. SBCL has extensive type inference and can catch and warn about many potential issues at compile time. And because of the pervasive use of macros in CL, successfully loading a library usually exercises a lot of code paths in its dependencies. To a surprising extent, “if it loads, it runs.”
+ +Qlot isn’t something a library would use. You use it to set up the dependencies for an application. My approach (with TBRSS) is this. Obviously, every time I upgrade to a new Quicklisp dist, I run a test suite to make sure everything is working together. On the rare occasion there’s a problem, I either pin the offending library to an older version (with Qlot) or I fork it and fix it, again using Qlot to pull from the fork until the fix makes it into the next Quicklisp dist. And of course I also use Qlot for dependencies that are not, for whatever reason, available in Quicklisp.
+
+ +
So Quicklisp’s author answers:
+ +++ +The work relying on me is that I build everything in Quicklisp to make sure they build together before making a release. This covers a useful class of bugs. I’d love to incorporate more tests in the process to catch release problems that don’t manifest at build time.
+ +I hope to make it easier for people to learn how to make their own dists. Then people will have the opportunity to make new software sets following the policies that are most important to them. I think there’s also plenty of room for other package managers for Common Lisp - maybe something styled more like clbuild would suit people who want instant access to updates.
+
Why a month ?
+ +++ +A month between updates is a compromise between chaos and stability.
+ +I don’t think shorter release cycles are an unqualified good. In my experience, short release cycles can lead to instability and unpredictability, and I chose one month as a balance between getting timely updates and having a reliable, stable base.
+ +The most labor-intensive part of making releases is monitoring daily failures and reporting bugs to the right people. The daily failure report is automated, but reporting bugs (and following up) can be a slog.
+
Then the discussion began. When voices support more frequent releases, +Zach advertises again +quicklisp-controller; +I read one (and only one) small but direct criticism towards the +maintainer:
+ +++ +@Hexstream I don’t think a fork will be required. I think this is less of an issue with @xach not willing to make changes required by the community and more of lack of manpower that’s willing and able to take up the burden of building and maintaining an automated Quicklisp dist/repository.
+
A one month update has its supporters, of course:
+ +++ +I have benefited multiple times from the 1 month release cycle and the due diligence that Xach and others put in every month. Even if they had a team of 50 I’d still vote to keep it as it is now. Making a separate dist is far more sensible if you need extra control over delivery times and it will still play well with quicklisp and your other projects.
+
I asked whether it would be possible to specify a git version, and I had an explanation:
+ +++ +Regarding pulling from git in the client, Quicklisp doesn’t work like that. I did not want to rely on external processes in order to be portable to all Common Lisp implementations and platforms. This was a real issue in clbuild and asdf-install.
+ +If you want to update a bugfix of your library, fix it, and wait a month.
+
and the reminder to try Qlot, +which allows exactly that (and to set dependencies locally).
+ +++ +Qlot will not help if you are writing a library and want to push fixes to its users quickly. It only helps for end-user application development. It works similar to virtualenv + pip (requirements.txt) from Python’s world, for example.
+
Phoe summed up the situation:
+ +++ +This thread is turning into a discussion about “why X approach is better than Quicklisp approach” which leads to a fruitful, but dead point.
+ +If someone is not satisfied with the way the current Quicklisp dist works and would rather have a more automated solution, then they are free to extend the quicklisp-controller to their liking and implement the required functionality for:
+ ++
+ +- creating a centralized service that acts as a QL repository and dist manager,
+- allowing the authors to upload and/or update their projects on that service,
+- setting up a CI test loop on that service for verifying that the packages build,
+- automatically updating the service’s dists with new releases,
+- maintaining all of the above.
+Until such a person or group of people appears, nothing is going to be be achieved and nothing in Quicklisp is going to change.
+ +Talk is cheap - @xach has at least built something that works and can act as a foundation.
+
And now, after only 17 messages to the thread, Zach Beane closes the thread:
+ +++ +I can appreciate there are other approaches that have advantages over how Quicklisp works. I hope this thread has helped shed some light on why it works the way it does, and my hopes for the future. I’m not against requests for changes, but not all of them can or will be accommodated. I’m also fully in favour of people doing their own thing if they have other priorities, experiences, and preferences - I think it would be great if there were even more options for Common Lisp project management.
+ +Closing this for now - thanks for the discussion.
+
Hexstream had just the time to disagree
+ +++ +Generally agree with your last comment, but I just wanted to express my discontent at the premature closing of this thread, it seemed pretty fruitful to me and I don’t think it had yet reached a point of serious diminishing returns.
+ +(Your project, your rules, though.)
+
and this is it.
+ ++ +
I think, and I’m not the only one, that the thread was fruitful.
+ +Indeed, we had explanations (that don’t appear in the doc), we had +presentation of means to the resolution (in no doc), we had the +presentation of how to fix the mentioned problem for library +developers (Qlot, comprehensibly not referenced in Quicklisp doc, and little talked +about over here), we had questions regarding the lack of documentation +that could be tracked from this thread (Zach too said he wanted to +write more doc). And I think the discussion was professional, with no +animosity. So we could have tracked some progress, maybe we would have +received more tips, but more importantly we’d have been done with this +question.
+ +But the thread is closed O_o Preventing people from communicating +means preventing people from learning from each +other, and thus makes the CL world evolving slower. Or people +quitting, or simply be very surprised and not staying here. Indeed, +it’s a negative feeling to see that. Why did Zach close the thread ? +Is he bored of this discussion ? He can ignore it. Bored of being +asked that ? It’s a recurrent question in reddit and in blogs. But +this issue is the only mention of the subject on Quicklisp’s website and +repository. Closing it makes it much less visible.
+ +Thus it is more likely newcomers will ask again. It’s sure newcomers +won’t learn why Quicklisp works like it does, which appears in good +light in that issue (and below in reddit). What happened is again a +thing that makes the CL world impenetrable (or with great effort) and +subject to rants. It doesn’t need more reasons, seriously.
+ +I wouldn’t bother if this subject was documented, but it is not. The +issue about documenting Quicklisp, which Zach wanted to fix “soon”, +stalls since 2014. It’s still open, at least.
+ ++ +
Final links, with a glimpse of light:
+ +-
+
- + +
Qi, a Common Lisp package +manager in the making - more traditional, no surprises - didn’t try.
+
+ 
+
+
+ Testing - in a nutshell
+MonkeyUser 22 08 2017
+
+
+ Analyse and test C with Python
+Posts on James Routley 16 08 2017
+
+
+ How We Replaced Dozens of Test Fixtures With One Simple Function
+Haki Benita 15 08 2017
+We had a large codebase and a lot of tests. Unfortunately, a lot of our tests were a relic from when we were using fixtures extensively. In this article, we describe a different approach that reduced the number of fixtures we maintain.
+
+
+ Life after the Recurse Center
+Posts on James Routley 15 08 2017
+
+ 
+
+
+ Interview vs. Reality
+MonkeyUser 15 08 2017
+
+
+ Improve Python testing with parameterisation
+Posts on James Routley 09 08 2017
+
+
+ Flavours of prayer
+James Sinclair 08 08 2017
+
+ 
+
+
+ Future Self
+MonkeyUser 08 08 2017
+
+ 
+
+
+ Refactor Man
+MonkeyUser 01 08 2017
+
+
+ How to do Functional Programming in Common Lisp ?
+Lisp journey 28 07 2017
+or “Common Lisp is not very functional-programming oriented”. What are the options ?
+ +I mean, map is uncommon and there is no short words like take etc
+for functional composition. Right ?
edit see those snippets.
+ +edit january, 2019: see this SO answer and the modf library.
+ +Map and filter
+ +Indeed, there are 8 or so map functions. The one we’re used to is
+mapcar. The simple map needs a second argument to specify its return
+type: (map 'list (lambda…. “filter” is named remove-if-not.
mapcan can also be useful. It concatenates the items into one
+list. So with mapcar we get a list of lists with our items, with
+mapcan simply a list of our items.
=> improved in cl21. It defines the usual map
+and keep-if and more functional verbs: take, drop, take-while,
+drop-while, butlast, sum,… in addition to fill, last,
+find-if[-not], remove-if[-not], delete[-if[-not]], reverse,
+reduce, sort, remove-duplicates, every, some,…
Note: remember that we still have access to cl symbols in CL21.
Functional composition
+ +Lack of functional composition ? There is the +Series library since 1989 +that seems great, it lets us “write our program in a functional style +without any runtime penalty at all !” +[malisper +on his blog post]
+ +But yes again, it has not the modern vocabulary we expect +and it seems abandonware (and its documentation is an old pdf paper +but now hopefully this wiki is better).
+ +edit 2021: GTWIWTG is a “generators” library similar in scope from Series, with modern idioms, but probably not as efficient. BTW, there are now lots of Series example snippets in the Cookbook/iteration page.
+ +CL21 has an operator to compose functions: https://github.com/cl21/cl21/wiki/Language-Difference-between-CL21-and-Common-Lisp#function
+ +Threading macros (pipes)
+ +We have two packages in Quicklisp:
+ +-
+
- cl-arrows defines
->, +->>and the generalized ones-<>and-<>>. At the time of +writing it has two unanswered PRs to add more, like the +“when-guarded”-“nil shortcuting diamond wand”some->.
+ - arrow-macros is a bit more
+complete but has more dependencies (it needs a code walker) which
+are not portable (failed on ECL, Allegro, ABCL, Clisp). It has the
+
some->,cond->andas->ones.
+
Data structures
+ +We have the nice FSet, the functional collection for Common Lisp.
+ +Anaphoric macros (for shorter lambdas)
+ +I like anaphoric macros but I didn’t find one ready to use in a library to write shorter lambdas. The first macro I wrote was directly to mimick elisp’s dash.el excellent library:
(defmacro --map (form list)
+ `(mapcar (lambda (it) ,form) ,list))
+so than we can write
+ +(--map (* it 2) '(2 3))
+instead of (mapcar (lambda (it) (* it 2) '(2 3))).
+This macro is very simple. It should be in a library, I don’t want to copy-paste it in every project of mine. => in CL21 ? In Anaphora ?
=> Personnally I’m very happy with +cl21’s short lambdas +(that were not documented…):
+ +(map ^(foo-bar %) items)
+or with (lm (x)…. Unused arguments will be ignored automatically.
I also quite like the Arc way of doing, that I found in the +Clamp project. Arc is another +language and Clamp is more of a POC I guess.
+ +For shorter lambdas we also have +f-underscore, that I see used +in the wild. It defines some macros to write shorter lambdas:
+ +-
+
fis a synonym for lambda
+f0is a lambda that takes 0 arguments
+f_takes one, accessible in_(underscore)
+f_ntakes one&restargument
+f_%ignores its rest argument
+mis a lambda “that has a macro-lambda-list instead of an ordinary lambda-list”.
+
You might like Trivia for pattern matching too.
+ +Hope this helps !
+ +
+
+ Data Structures
+Lisp journey 27 07 2017
+What the heck are alists and plists exactly, how do we manipulate data +structures ? It seems tedious sometimes, are there helpers ?
+ +Best read in the Cookbook.
+ +We hope to give here a clear reference of the common data +structures. To really learn the language, you should take the time to +read other resources. The following ones, which we relied upon, +have many more details:
+ +-
+
- Practical CL, by Peter Seibel +
- CL Recipes, by E. Weitz, full of explanations and tips, +
- the +CL standard +with a nice TOC, functions reference, extensive descriptions, more +examples and warnings (i.e: everything). +
- a Common Lisp quick reference +
Table of Contents
+ +-
+
- Building lists. Cons cells, lists.
+
+
-
+
- car/cdr or first/rest (and second… to tenth) +
- last, butlast, nbutlast (&optional n) +
- reverse, nreverse +
- append +
- push (item, place) +
- pop +
- nthcdr (index, list) +
- car/cdr and composites (cadr, caadr…) - accessing lists inside lists +
- destructuring-bind (parameter*, list) +
- Predicates: null, listp +
- ldiff, tailp, list*, make-list, fill, revappend, nreconc, consp, atom +
+ - Sequences
+
+
-
+
- Predicates: every, some,… +
- Functions
+
+
-
+
- length (sequence) +
- member (elt, sequence) +
- elt (sequence, index) +
- count (foo sequence) +
- subseq (sequence start, [end]) +
- sort, stable-sort (sequence, test [, key function]) +
- find, position (foo, sequence) +
- search (sequence-a, sequence-b) +
- substitute, nsubstitute[if,if-not] +
- sort, stable-sort, merge +
- replace (sequence-a, sequence-b) +
- remove, delete (foo sequence) +
+ - mapping (map, mapcar, remove-if[-not],…) +
- Flatten a list (Alexandria) +
- Creating lists with variables +
- Comparing lists +
+ - Set +
- Fset - immutable data structure +
- Arrays and vectors + + +
- Hash Table + + +
- Alist +
- Plist +
- Tree + + +
Lists
+ +Building lists. Cons cells, lists.
+ +A list is also a sequence, so we can use the functions shown below.
+ +The list basic element is the cons cell. We build lists by assembling +cons cells.
+ +(cons 1 2)
+;; => (1 . 2) ;; representation with a point, a dotted pair.
+It looks like this:
+ +[o|o]--- 2
+ |
+ 1
+If the cdr of the first cell is another cons cell, and if the cdr of
+this last one is nil, we build a list:
(cons 1 (cons 2 nil))
+;; => (1 2)
+It looks like this:
+ +[o|o]---[o|/]
+ | |
+ 1 2
+(ascii art by draw-cons-tree).
+ +See that the representation is not a dotted pair ? The Lisp printer +understands the convention.
+ +Finally we can simply build a literal list with list:
(list 1 2)
+;; => (1 2)
+or by calling quote:
+ +'(1 2)
+;; => (1 2)
+which is shorthand notation for the function call (quote (1 2)).
car/cdr or first/rest (and second… to tenth)
+ +(car (cons 1 2)) ;; => 1
+(cdr (cons 1 2)) ;; => 2
+(first (cons 1 2)) ;; => 1
+(first '(1 2 3)) ;; => 1
+(rest '(1 2 3)) ;; => (2 3)
+We can assign any new value with setf.
last, butlast, nbutlast (&optional n)
+ +return the last cons cell in a list (or the nth last cons cells).
+ +(last '(1 2 3))
+;; => (3)
+(car (last '(1 2 3)) )
+;; => 3
+(butlast '(1 2 3))
+;; => (1 2)
+reverse, nreverse
+ +reverse and nreverse return a new sequence.
nreverse is destructive. The N stands for non-consing, meaning
+it doesn’t need to allocate any new cons cells. It might (but in
+practice, does) reuse and modify the original sequence:
(defparameter mylist '(1 2 3))
+;; => (1 2 3)
+(reverse mylist)
+;; => (3 2 1)
+mylist
+;; => (1 2 3)
+(nreverse mylist)
+;; => (3 2 1)
+mylist
+;; => (1) in SBCL but implementation dependant.
+append
+ +append takes any number of list arguments and returns a new list
+containing the elements of all its arguments:
(append (list 1 2) (list 3 4))
+;; => (1 2 3 4)
+The new list shares some cons cells with the (3 4):
http://gigamonkeys.com/book/figures/after-append.png
+ +Note: cl21’s append is generic (for strings, lists, vectors and
+its abstract-sequence).
nconc is the recycling equivalent.
push (item, place)
+ +push prepends item to the list that is stored in place, stores
+the resulting list in place, and returns the list.
(defparameter mylist '(1 2 3))
+(push 0 mylist)
+;; => (0 1 2 3)
+(defparameter x ’(a (b c) d))
+;; => (A (B C) D)
+(push 5 (cadr x))
+;; => (5 B C)
+x
+;; => (A (5 B C) D)
+push is equivalent to (setf place (cons item place )) except that
+the subforms of place are evaluated only once, and item is evaluated
+before place.
There is no built-in function to add to the end of a list. It is a
+more costly operation (have to traverse the whole list). So if you
+need to do this: either consider using another data structure, either
+just reverse your list when needed.
pop
+ +a destructive operation.
+ +nthcdr (index, list)
+ +Use this if first, second and the rest up to tenth are not
+enough.
car/cdr and composites (cadr, caadr…) - accessing lists inside lists
+ +They make sense when applied to lists containing other lists.
+ +(caar (list 1 2 3)) ==> error
+(caar (list (list 1 2) 3)) ==> 1
+(cadr (list (list 1 2) (list 3 4))) ==> (3 4)
+(caadr (list (list 1 2) (list 3 4))) ==> 3
+destructuring-bind (parameter*, list)
+ +It binds the parameter values to the list elements. We can destructure +trees, plists and even provide defaults.
+ +Simple matching:
+ +(destructuring-bind (x y z) (list 1 2 3)
+ (list :x x :y y :z z))
+;; => (:X 1 :Y 2 :Z 3)
+Matching inside sublists:
+ +(destructuring-bind (x (y1 y2) z) (list 1 (list 2 20) 3)
+ (list :x x :y1 y1 :y2 y2 :z z))
+;; => (:X 1 :Y1 2 :Y2 20 :Z 3)
+The parameter list can use the usual &optional, &rest and &key
+parameters.
(destructuring-bind (x (y1 &optional y2) z) (list 1 (list 2) 3)
+ (list :x x :y1 y1 :y2 y2 :z z))
+;; => (:X 1 :Y1 2 :Y2 NIL :Z 3)
+(destructuring-bind (&key x y z) (list :z 1 :y 2 :x 3)
+ (list :x x :y y :z z))
+;; => (:X 3 :Y 2 :Z 1)
+The &whole parameter is bound to the whole list. It must be the
+first one and others can follow.
(destructuring-bind (&whole whole-list &key x y z) (list :z 1 :y 2 :x 3)
+ (list :x x :y y :z z :whole whole-list))
+;; => (:X 3 :Y 2 :Z 1 :WHOLE-LIST (:Z 1 :Y 2 :X 3))
+Destructuring a plist, giving defaults:
+ +(example from Common Lisp Recipes, by E. Weitz, Apress, 2016)
+ +(destructuring-bind (&key a (b :not-found) c
+ &allow-other-keys)
+ ’(:c 23 :d "D" :a #\A :foo :whatever)
+ (list a b c))
+;; => (#\A :NOT-FOUND 23)
+If this gives you the will to do pattern matching, see +pattern matching.
+ +Predicates: null, listp
+ +null is equivalent to not, but considered better style.
listp tests wether an object is a cons cell or nil.
and sequences’ predicates.
+ +ldiff, tailp, list*, make-list, fill, revappend, nreconc, consp, atom
+ +(make-list 3 :initial-element "ta")
+;; => ("ta" "ta" "ta")
+(make-list 3)
+;; => (NIL NIL NIL)
+(fill * "hello")
+;; => ("hello" "hello" "hello")
+Sequences
+ +lists and vectors (and thus strings) are sequences.
+ +Note: see also the strings page.
+ +Many of the sequence functions take keyword arguments. All keyword +arguments are optional and, if specified, may appear in any order.
+ +Pay attention to the :test argument. It defaults to eql (for
+strings, use :equal).
The :key argument should be passed either nil, or a function of one
+argument. This key function is used as a filter through which the
+elements of the sequence are seen. For instance, this:
(find x y :key 'car)
+is similar to (assoc* x y): It searches for an element of the list
+whose car equals x, rather than for an element which equals x
+itself. If :key is omitted or nil, the filter is effectively the
+identity function.
Example with an alist (see definition below):
+ +(defparameter my-alist (list (cons 'foo "foo")
+ (cons 'bar "bar")))
+;; => ((FOO . "foo") (BAR . "bar"))
+(find 'bar my-alist)
+;; => NIL
+(find 'bar my-alist :key 'car)
+;; => (BAR . "bar")
+For more, use a lambda that takes one parameter.
(find 'bar my-alist :key (lambda (it) (car it)))
+Note: and cl21 has short lambdas:
+ +(find 'bar my-alist :key ^(car %))
+(find 'bar my-alist :key (lm (it) (car it)))
+Predicates: every, some,…
+ +every, notevery (test, sequence): return nil or t, respectively, as
+soon as one test on any set of the corresponding elements of sequences
+returns nil.
(defparameter foo '(1 2 3))
+(every #'evenp foo)
+;; => NIL
+(some #'evenp foo)
+;; => T
+with a list of strings:
+ +(defparameter str '("foo" "bar" "team"))
+(every #'stringp str)
+;; => T
+(some #'(lambda (it) (= 3 (length it))) str)
+;; => T
+(some ^(= 3 (length %)) str) ;; in CL21
+;; => T
+some, notany (test, sequence): return either the value of the test, or nil.
mismatch (sequence-a, sequence-b): Return position in sequence-a where
+sequence-a and sequence-b begin to mismatch. Return NIL if they match
+entirely. Other parameters: :from-end bool, :start1, :start2 and
+their :end[1,2].
Functions
+ +See also sequence functions defined in
+Alexandria:
+starts-with, ends-with, ends-with-subseq, length=, emptyp,…
length (sequence)
+ +member (elt, sequence)
+ +elt (sequence, index)
+ +beware, here the sequence comes first.
+ +count (foo sequence)
+ +Return the number of elements in sequence that match foo.
+ +Additional paramaters: :from-end, :start, :end.
See also count-if, count-not (test-function sequence).
subseq (sequence start, [end])
+ +It is “setf”able, but only works if the new sequence has the same +length of the one to replace.
+ +sort, stable-sort (sequence, test [, key function])
+ +find, position (foo, sequence)
+ +also find-if, find-if-not, position-if, position-if-not (test
+sequence). See :key and :test parameters.
search (sequence-a, sequence-b)
+ +Search sequence-b for a subsequence matching sequence-a. Return
+position in sequence-b, or NIL. Has the from-end, end1/2 and others
+parameters.
substitute, nsubstitute[if,if-not]
+ +sort, stable-sort, merge
+ +replace (sequence-a, sequence-b)
+ +Replace elements of sequence-a with elements of +sequence-b.
+ +remove, delete (foo sequence)
+ +Make a copy of sequence without elements matching foo. Has
+:start/end, :key and :count parameters.
delete is the recycling version of remove.
(remove "foo" '("foo" "bar" "foo") :test 'equal)
+;; => ("bar")
+see also remove-if[-not] below.
mapping (map, mapcar, remove-if[-not],…)
+ +If you’re used to map and filter in other languages, you probably want
+mapcar. But it only works on lists, so to iterate on vectors (and
+produce either a vector or a list, use (map 'list function vector).
mapcar also accepts multiple lists with &rest more-seqs. The
+mapping stops as soon as the shortest sequence runs out.
Note: cl21’s map is a generic mapcar for lists and vectors.
map takes the output-type as first argument ('list, 'vector or
+'string):
(defparameter foo '(1 2 3))
+(map 'list (lambda (it) (* 10 it)) foo)
+reduce (function, sequence). Special parameter: :initial-value.
(reduce '- '(1 2 3 4))
+;; => -8
+(reduce '- '(1 2 3 4) :initial-value 100)
+;; => 90
+Filter is here called remove-if-not.
Flatten a list (Alexandria)
+ +With
+Alexandria,
+we have the flatten function.
Creating lists with variables
+ +That’s one use of the backquote:
(defparameter *var* "bar")
+;; First try:
+'("foo" *var* "baz") ;; no backquote
+;; => ("foo" *VAR* "baz") ;; nope
+Second try, with backquote interpolation:
+ +`("foo" ,*var* "baz") ;; backquote, comma
+;; => ("foo" "bar" "baz") ;; good
+The backquote first warns we’ll do interpolation, the comma introduces +the value of the variable.
+ +If our variable is a list:
+ +(defparameter *var* '("bar" "baz"))
+;; First try:
+`("foo" ,*var*)
+;; => ("foo" ("bar" "baz")) ;; nested list
+`("foo" ,@*var*) ;; backquote, comma-@ to
+;; => ("foo" "bar" "baz")
+E. Weitz warns that “objects generated this way will very likely share +structure (see Recipe 2-7)“.
+ +Comparing lists
+ +We can use sets functions.
+ +Set
+ +intersection
What elements are both in list-a and list-b ?
+ +(defparameter list-a '(0 1 2 3))
+(defparameter list-b '(0 2 4))
+(intersection list-a list-b)
+;; => (2 0)
+set-difference
Remove the elements of list-b from list-a:
+ +(set-difference list-a list-b)
+;; => (3 1)
+(set-difference list-b list-a)
+;; => (4)
+union
join the two lists:
+ +(union list-a list-b)
+;; => (3 1 0 2 4) ;; order can be different in your lisp
+set-exclusive-or
Remove the elements that are in both lists:
+ +(set-exclusive-or list-a list-b)
+;; => (4 3 1)
+and their recycling “n” counterpart (nintersection,…).
See also functions in
+Alexandria:
+setp, set-equal,…
Fset - immutable data structure
+ +You may want to have a look at the +FSet +library (in Quicklisp).
+ +Arrays and vectors
+ +Arrays have constant-time access characteristics.
+ +They can be fixed or adjustable. A simple array is neither displaced
+(using :displaced-to, to point to another array) nor adjustable
+(:adjust-array), nor does it have a fill pointer (fill-pointer,
+that moves when we add or remove elements).
A vector is an array with rank 1 (of one dimension). It is also a +sequence (see above).
+ +A simple vector is a simple array that is also not specialized (it
+doesn’t use :element-type to set the types of the elements).
Create an array, one or many dimensions
+ +make-array (sizes-list :adjustable bool)
adjust-array (array, sizes-list, :element-type, :initial-element)
Access: aref (array i [j …])
+ +aref (array i j k …) or row-major-aref (array i) equivalent to
+(aref i i i …).
The result is setfable.
(defparameter myarray (make-array '(2 2 2) :initial-element 1))
+myarray
+;; => #3A(((1 1) (1 1)) ((1 1) (1 1)))
+(aref myarray 0 0 0)
+;; => 1
+(setf (aref myarray 0 0 0) 9)
+;; => 9
+(row-major-aref myarray 0)
+;; => 9
+Sizes
+ +array-total-size (array): how many elements will fit in the array ?
array-dimensions (array): list containing the length of the array’s dimensions.
array-dimension (array i): length of the *i*th dimension.
array-rank number of dimensions of the array.
(defparameter myarray (make-array '(2 2 2)))
+;; => MYARRAY
+myarray
+;; => #3A(((0 0) (0 0)) ((0 0) (0 0)))
+(array-rank myarray)
+;; => 3
+(array-dimensions myarray)
+;; => (2 2 2)
+(array-dimension myarray 0)
+;; => 2
+(array-total-size myarray)
+;; => 8
+Vectors
+ +Create with vector or the reader macro #(). It returns a simple
+vector.
(vector 1 2 3)
+;; => #(1 2 3)
+#(1 2 3)
+;; => #(1 2 3)
+vector-push (foo vector): replace the vector element pointed to by
+the fill pointer by foo. Can be destructive.
vector-push-extend *(foo vector [extension-num])*t
vector-pop (vector): return the element of vector its fill pointer
+points to.
fill-pointer (vector). setfable.
and see also the sequence functions.
+ +Transforming a vector to a list.
+ +If you’re mapping over it, see the map function whose first parameter
+is the result type.
Or use (coerce vector 'list).
Hash Table
+ +Hash Tables are a powerful data structure, associating keys with +values in a very efficient way. Hash Tables are often preferred over +association lists whenever performance is an issue, but they introduce +a little overhead that makes assoc lists better if there are only a +few key-value pairs to maintain.
+ +Alists can be used sometimes differently though:
+ +-
+
- they can be ordered +
- we can push cons cells that have the same key, remove the one in +front and we have a stack +
- they have a human-readable printed representation +
- they can be easily (de)serialized +
- because of RASSOC, keys and values in alists are essentially +interchangeable; whereas in hash tables, keys and values play very +different roles (as usual, see CL Recipes for more). +
Creating a Hash Table
+ +Hash Tables are created using the function
+make-hash-table. It
+has no required argument. Its most used optional keyword argument is
+:test, specifying the function used to test the equality of keys.
If we are using the cl21 extension library, we can
+create a hash table and add elements in the same time with the new
+#H reader syntax:
(defparameter *my-hash* #H(:name "Eitaro Fukamachi"))
+then we access an element with
+ +(getf *my-hash* :name)
+Getting a value from a Hash Table
+ +The function
+gethash
+takes two required arguments: a key and a hash table. It returns two
+values: the value corresponding to the key in the hash table (or nil
+if not found), and a boolean indicating whether the key was found in
+the table. That second value is necessary since nil is a valid value
+in a key-value pair, so getting nil as first value from gethash
+does not necessarily mean that the key was not found in the table.
Getting a key that does not exist with a default value
+ +gethash has an optional third argument:
(gethash 'bar *my-hash* "default-bar")
+;; => "default-bar"
+;; NIL
+Getting all keys or all values of a hash table
+ +The
+Alexandria
+library (in Quicklisp) has the functions hash-table-keys and
+hash-table-values for that.
(ql:quickload :alexandria)
+;; […]
+(alexandria:hash-table-keys *my-hash*)
+;; => (BAR)
+Adding an Element to a Hash Table
+ +If you want to add an element to a hash table, you can use gethash,
+the function to retrieve elements from the hash table, in conjunction
+with
+setf.
CL-USER> (defparameter *my-hash* (make-hash-table))
+*MY-HASH*
+CL-USER> (setf (gethash 'one-entry *my-hash*) "one")
+"one"
+CL-USER> (setf (gethash 'another-entry *my-hash*) 2/4)
+1/2
+CL-USER> (gethash 'one-entry *my-hash*)
+"one"
+T
+CL-USER> (gethash 'another-entry *my-hash*)
+1/2
+T
+Testing for the Presence of a Key in a Hash Table
+ +The first value returned by gethash is the object in the hash table
+that’s associated with the key you provided as an argument to
+gethash or nil if no value exists for this key. This value can act
+as a
+generalized boolean if you want to test for the presence of keys.
CL-USER> (defparameter *my-hash* (make-hash-table))
+*MY-HASH*
+CL-USER> (setf (gethash 'one-entry *my-hash*) "one")
+"one"
+CL-USER> (if (gethash 'one-entry *my-hash*)
+ "Key exists"
+ "Key does not exist")
+"Key exists"
+CL-USER> (if (gethash 'another-entry *my-hash*)
+ "Key exists"
+ "Key does not exist")
+"Key does not exist"
+But note that this does not work if nil is amongst the values that
+you want to store in the hash.
CL-USER> (setf (gethash 'another-entry *my-hash*) nil)
+NIL
+CL-USER> (if (gethash 'another-entry *my-hash*)
+ "Key exists"
+ "Key does not exist")
+"Key does not exist"
+In this case you’ll have to check the second return value of gethash which will always return nil if no value is found and T otherwise.
CL-USER> (if (nth-value 1 (gethash 'another-entry *my-hash*))
+ "Key exists"
+ "Key does not exist")
+"Key exists"
+CL-USER> (if (nth-value 1 (gethash 'no-entry *my-hash*))
+ "Key exists"
+ "Key does not exist")
+"Key does not exist"
+Deleting from a Hash Table
+ +Use
+remhash
+to delete a hash entry. Both the key and its associated value will be
+removed from the hash table. remhash returns T if there was such an
+entry, nil otherwise.
CL-USER> (defparameter *my-hash* (make-hash-table))
+*MY-HASH*
+CL-USER> (setf (gethash 'first-key *my-hash*) 'one)
+ONE
+CL-USER> (gethash 'first-key *my-hash*)
+ONE
+T
+CL-USER> (remhash 'first-key *my-hash*)
+T
+CL-USER> (gethash 'first-key *my-hash*)
+NIL
+NIL
+CL-USER> (gethash 'no-entry *my-hash*)
+NIL
+NIL
+CL-USER> (remhash 'no-entry *my-hash*)
+NIL
+CL-USER> (gethash 'no-entry *my-hash*)
+NIL
+NIL
+Traversing a Hash Table
+ +If you want to perform an action on each entry (i.e., each key-value +pair) in a hash table, you have several options:
+ +You can use
+maphash
+which iterates over all entries in the hash table. Its first argument
+must be a function which accepts two arguments, the key and the
+value of each entry. Note that due to the nature of hash tables you
+can’t control the order in which the entries are provided by
+maphash (or other traversing constructs). maphash always returns
+nil.
CL-USER> (defparameter *my-hash* (make-hash-table))
+*MY-HASH*
+CL-USER> (setf (gethash 'first-key *my-hash*) 'one)
+ONE
+CL-USER> (setf (gethash 'second-key *my-hash*) 'two)
+TWO
+CL-USER> (setf (gethash 'third-key *my-hash*) nil)
+NIL
+CL-USER> (setf (gethash nil *my-hash*) 'nil-value)
+NIL-VALUE
+CL-USER> (defun print-hash-entry (key value)
+ (format t "The value associated with the key ~S is ~S~%" key value))
+PRINT-HASH-ENTRY
+CL-USER> (maphash #'print-hash-entry *my-hash*)
+The value associated with the key FIRST-KEY is ONE
+The value associated with the key SECOND-KEY is TWO
+The value associated with the key THIRD-KEY is NIL
+The value associated with the key NIL is NIL-VALUE
+You can also use
+with-hash-table-iterator,
+a macro which turns (via
+macrolet)
+its first argument into an iterator that on each invocation returns
+three values per hash table entry - a generalized boolean that’s true
+if an entry is returned, the key of the entry, and the value of the
+entry. If there are no more entries, only one value is returned -
+nil.
;;; same hash-table as above
+CL-USER> (with-hash-table-iterator (my-iterator *my-hash*)
+ (loop
+ (multiple-value-bind (entry-p key value)
+ (my-iterator)
+ (if entry-p
+ (print-hash-entry key value)
+ (return)))))
+The value associated with the key FIRST-KEY is ONE
+The value associated with the key SECOND-KEY is TWO
+The value associated with the key THIRD-KEY is NIL
+The value associated with the key NIL is NIL-VALUE
+NIL
+Note the following caveat from the HyperSpec: “It is unspecified what
+happens if any of the implicit interior state of an iteration is
+returned outside the dynamic extent of the with-hash-table-iterator
+form such as by returning some closure over the invocation form.”
And there’s always loop:
;;; same hash-table as above
+CL-USER> (loop for key being the hash-keys of *my-hash*
+ do (print key))
+FIRST-KEY
+SECOND-KEY
+THIRD-KEY
+NIL
+NIL
+CL-USER> (loop for key being the hash-keys of *my-hash*
+ using (hash-value value)
+ do (format t "The value associated with the key ~S is ~S~%" key value))
+The value associated with the key FIRST-KEY is ONE
+The value associated with the key SECOND-KEY is TWO
+The value associated with the key THIRD-KEY is NIL
+The value associated with the key NIL is NIL-VALUE
+NIL
+CL-USER> (loop for value being the hash-values of *my-hash*
+ do (print value))
+ONE
+TWO
+NIL
+NIL-VALUE
+NIL
+CL-USER> (loop for value being the hash-values of *my-hash*
+ using (hash-key key)
+ do (format t "~&~A -> ~A" key value))
+FIRST-KEY -> ONE
+SECOND-KEY -> TWO
+THIRD-KEY -> NIL
+NIL -> NIL-VALUE
+NIL
+Last, we also have cl21’s (doeach ((key val) *hash*) …).
Traversign keys or values
+ +To map over keys or values we can again rely on Alexandria with
+maphash-keys and maphash-values.
Counting the Entries in a Hash Table
+ +No need to use your fingers - Common Lisp has a built-in function to
+do it for you:
+hash-table-count.
CL-USER> (defparameter *my-hash* (make-hash-table))
+*MY-HASH*
+CL-USER> (hash-table-count *my-hash*)
+0
+CL-USER> (setf (gethash 'first *my-hash*) 1)
+1
+CL-USER> (setf (gethash 'second *my-hash*) 2)
+2
+CL-USER> (setf (gethash 'third *my-hash*) 3)
+3
+CL-USER> (hash-table-count *my-hash*)
+3
+CL-USER> (setf (gethash 'second *my-hash*) 'two)
+TWO
+CL-USER> (hash-table-count *my-hash*)
+3
+CL-USER> (clrhash *my-hash*)
+#<EQL hash table, 0 entries {48205F35}>
+CL-USER> (hash-table-count *my-hash*)
+0
+Performance Issues: The Size of your Hash Table
+ +The make-hash-table function has a couple of optional parameters
+which control the initial size of your hash table and how it’ll grow
+if it needs to grow. This can be an important performance issue if
+you’re working with large hash tables. Here’s an (admittedly not very
+scientific) example with CMUCL pre-18d on
+Linux:
CL-USER> (defparameter *my-hash* (make-hash-table))
+*MY-HASH*
+CL-USER> (hash-table-size *my-hash*)
+65
+CL-USER> (hash-table-rehash-size *my-hash*)
+1.5
+CL-USER> (time (dotimes (n 100000) (setf (gethash n *my-hash*) n)))
+Compiling LAMBDA NIL:
+Compiling Top-Level Form:
+
+Evaluation took:
+ 0.27 seconds of real time
+ 0.25 seconds of user run time
+ 0.02 seconds of system run time
+ 0 page faults and
+ 8754768 bytes consed.
+NIL
+CL-USER> (time (dotimes (n 100000) (setf (gethash n *my-hash*) n)))
+Compiling LAMBDA NIL:
+Compiling Top-Level Form:
+
+Evaluation took:
+ 0.05 seconds of real time
+ 0.05 seconds of user run time
+ 0.0 seconds of system run time
+ 0 page faults and
+ 0 bytes consed.
+NIL
+The values for
+hash-table-size
+and
+hash-table-rehash-size
+are implementation-dependent. In our case, CMUCL chooses and initial
+size of 65, and it will increase the size of the hash by 50 percent
+whenever it needs to grow. Let’s see how often we have to re-size the
+hash until we reach the final size…
CL-USER> (log (/ 100000 65) 1.5)
+18.099062
+CL-USER> (let ((size 65)) (dotimes (n 20) (print (list n size)) (setq size (* 1.5 size))))
+(0 65)
+(1 97.5)
+(2 146.25)
+(3 219.375)
+(4 329.0625)
+(5 493.59375)
+(6 740.3906)
+(7 1110.5859)
+(8 1665.8789)
+(9 2498.8184)
+(10 3748.2275)
+(11 5622.3413)
+(12 8433.512)
+(13 12650.268)
+(14 18975.402)
+(15 28463.104)
+(16 42694.656)
+(17 64041.984)
+(18 96062.98)
+(19 144094.47)
+NIL
+The hash has to be re-sized 19 times until it’s big enough to hold +100,000 entries. That explains why we saw a lot of consing and why it +took rather long to fill the hash table. It also explains why the +second run was much faster - the hash table already had the correct +size.
+ +Here’s a faster way to do it: +If we know in advance how big our hash will be, we can start with the right size:
+ +CL-USER> (defparameter *my-hash* (make-hash-table :size 100000))
+*MY-HASH*
+CL-USER> (hash-table-size *my-hash*)
+100000
+CL-USER> (time (dotimes (n 100000) (setf (gethash n *my-hash*) n)))
+Compiling LAMBDA NIL:
+Compiling Top-Level Form:
+
+Evaluation took:
+ 0.04 seconds of real time
+ 0.04 seconds of user run time
+ 0.0 seconds of system run time
+ 0 page faults and
+ 0 bytes consed.
+NIL
+That’s obviously much faster. And there was no consing involved
+because we didn’t have to re-size at all. If we don’t know the final
+size in advance but can guess the growth behaviour of our hash table
+we can also provide this value to make-hash-table. We can provide an
+integer to specify absolute growth or a float to specify relative
+growth.
CL-USER> (defparameter *my-hash* (make-hash-table :rehash-size 100000))
+*MY-HASH*
+CL-USER> (hash-table-size *my-hash*)
+65
+CL-USER> (hash-table-rehash-size *my-hash*)
+100000
+CL-USER> (time (dotimes (n 100000) (setf (gethash n *my-hash*) n)))
+Compiling LAMBDA NIL:
+Compiling Top-Level Form:
+
+Evaluation took:
+ 0.07 seconds of real time
+ 0.05 seconds of user run time
+ 0.01 seconds of system run time
+ 0 page faults and
+ 2001360 bytes consed.
+NIL
+Also rather fast (we only needed one re-size) but much more consing +because almost the whole hash table (minus 65 initial elements) had to +be built during the loop.
+ +Note that you can also specify the rehash-threshold while creating a
+new hash table. One final remark: Your implementation is allowed to
+completely ignore the values provided for rehash-size and
+rehash-threshold…
Alist
+ +An association list is a list of cons cells.
+ +This simple example:
+ +(defparameter my-alist (list (cons 'foo "foo")
+ (cons 'bar "bar")))
+;; => ((FOO . "foo") (BAR . "bar"))
+looks like this:
+ +[o|o]---[o|/]
+ | |
+ | [o|o]---"bar"
+ | |
+ | BAR
+ |
+[o|o]---"foo"
+ |
+FOO
+The constructor pairlis associates a list of keys and a list of values:
(pairlis '(:foo :bar)
+ '("foo" "bar"))
+;; => ((:BAR . "bar") (:FOO . "foo"))
+To get a key, we have assoc (use :test 'equal when your keys are
+strings, as usual). It returns the whole cons cell, so you may want to
+use cdr or second to get the value. There is assoc-if, and
+rassoc to get a cons cell by its value.
To add a key, we push another cons cell:
(push (cons 'team "team") my-alist)
+;; => ((TEAM . "team") (FOO . "foo") (BAR . "bar"))
+We can use pop and other functions that operate on lists, like remove:
(remove :team my-alist)
+;; => ((:TEAM . "team") (FOO . "foo") (BAR . "bar")) ;; didn't remove anything
+(remove :team my-alist :key 'car)
+;; => ((FOO . "foo") (BAR . "bar")) ;; returns a copy
+Remove only one element with :count:
(push (cons 'bar "bar2") my-alist)
+;; => ((BAR . "bar2") (TEAM . "team") (FOO . "foo") (BAR . "bar")) ;; twice the 'bar key
+(remove 'bar my-alist :key 'car :count 1)
+;; => ((TEAM . "team") (FOO . "foo") (BAR . "bar"))
+;; because otherwise:
+(remove 'bar my-alist :key 'car)
+;; => ((TEAM . "team") (FOO . "foo")) ;; no more 'bar
+In the
+Alexandria
+library, see some functions like remove-from-plist, alist-plist,…
Plist
+ +A property list is simply a list that alternates a key, a value, and
+so on, where its keys are symbols (we can not set its :test). More
+precisely, it first has a cons cell whose car is the key, whose
+cdr points to the following cons cell whose car is the
+value.
For example this plist:
+ +(defparameter my-plist (list 'foo "foo" 'bar "bar"))
+looks like this:
+ +[o|o]---[o|o]---[o|o]---[o|/]
+ | | | |
+FOO "foo" BAR "bar"
+
+We access an element with getf (list elt) (it returns the value)
+(the list comes as first element),
we remove an element with remf.
(defparameter my-plist (list 'foo "foo" 'bar "bar"))
+;; => (FOO "foo" BAR "bar")
+(setf (getf my-plist 'foo) "foo!!!")
+;; => "foo!!!"
+Tree
+ +tree-equal, copy-tree. They descend recursively into the car and
+the cdr of the cons cells they visit.
Sycamore - purely functional weight-balanced binary trees
+ +https://github.com/ndantam/sycamore
+ +Features:
+ +-
+
- Fast, purely functional weight-balanced binary trees.
+
+
-
+
- Leaf nodes are simple-vectors, greatly reducing tree height. +
+ - Interfaces for tree Sets and Maps (dictionaries). +
- Ropes +
- Purely functional pairing heaps +
- Purely functional amortized queue. +
See more in other resources !
+ +
+ 
+
+
+ A Programmer Walks Into A Bar
+MonkeyUser 26 07 2017
+
+
+
+
+ Fingerprinting
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ How facebook knows exactly what turns you on
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ Tracker Categories
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ Where does the data come from?
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ Tracking Pixel
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ What is a tracker?
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ Cookies
+WhoTracksMe blog 21 07 2017
+
+
+
+
+ How Cliqz anti-tracking protects users
+WhoTracksMe blog 21 07 2017
+
+
+ Simplify Golang test fixtures with this one weird trick
+Posts on James Routley 20 07 2017
+
+
+ PSA: cp -r behaves differently on linux and macOS
+Posts on James Routley 20 07 2017
+
+ 
+
+
+ Bottom of the backlog
+MonkeyUser 18 07 2017
+
+
+ Investigating tries: writing a spell-checking algorithm
+Posts on James Routley 16 07 2017
+
+ 
+
+
+ Big Decisions
+MonkeyUser 10 07 2017
+
+
+ How to Manage Concurrency in Django Models
+Haki Benita 06 07 2017
+The days of desktop systems serving single users are long gone. Web applications nowadays are serving millions of users at the same time. With many users comes a wide range of new problems: concurrency problems. In this article we describe two approaches for managing concurrency in Django models.
+
+
+ Microplásticos, enemigos del mar (III)
+Andanzas de una ambientóloga . . . 04 07 2017
+
+ 
+
+
+ NPM Delivery
+MonkeyUser 04 07 2017
+
+ 
+
+
+ Cuentidubi: la app de los cuentos infantiles
+Legión del Espacio 03 07 2017
+
+
+ Common Lisp Async Web Scraping
+Lisp journey 29 06 2017
+The set of tools to do web scraping in Common Lisp is pretty complete +and pleasant. In this short tutorial we’ll see how to make http +requests, parse html, extract content and do asynchronous requests.
+ +Our simple task will be to extract the list of links on the CL +Cookbook’s index page and check if they are reachable.
+ +Best read in the Cookbook !
+ +We’ll use the following libraries:
+ +-
+
- Dexador - an HTTP client +(that aims at replacing the venerable Drakma), +
- Plump - a markup parser, that works on malformed HTML, +
- Lquery - a DOM manipulation +library, to extract content from our Plump result, +
- lparallel - a library for parallel programming (read more in the process section). +
Before starting let’s install those libraries with Quicklisp:
+ +(ql:quickload '(:dexador :plump :lquery :lparallel))
+Table of Contents
+ + + + + +HTTP Requests
+ +Easy things first. Install Dexador. Then we use the get function:
(defvar *url* "https://lispcookbook.github.io/cl-cookbook/")
+(defvar *request* (dex:get *url*))
+This returns a list of values: the whole page content, the return code +(200), the response headers, the uri and the stream.
+ +"<!DOCTYPE html>
+ <html lang=\"en\">
+ <head>
+ <title>Home – the Common Lisp Cookbook</title>
+ […]
+ "
+200
+#<HASH-TABLE :TEST EQUAL :COUNT 19 {1008BF3043}>
+#<QURI.URI.HTTP:URI-HTTPS https://lispcookbook.github.io/cl-cookbook/>
+#<CL+SSL::SSL-STREAM for #<FD-STREAM for "socket 192.168.0.23:34897, peer: 151.101.120.133:443" {100781C133}>>
+
+Remember, in Slime we can inspect the objects with a right-click on +them.
+ +Parsing and extracting content with CSS selectors
+ +We’ll use Plump to parse the html and Lquery to extract
+content. They have nice documentation:
(defvar *parsed-content* (plump:parse *request*))
+;; => *PARSED-CONTENT**
+*parsed-content**
+;; => #<PLUMP-DOM:ROOT {1009EE5FE3}>
+Now we’ll extract the links with CSS selectors.
+ +Note: to find out what should be the CSS selector of the element +I’m interested in, I right click on an element in the browser and I +choose “Inspect element”. This opens up the inspector of my browser’s +web dev tool and I can study the page structure.
+ +So the links I want to extract are in a page with an id of value
+“content”, and they are in regular list elements (li).
Let’s try something:
+ +(lquery:$ *parsed-content* "#content li")
+;; => #(#<PLUMP-DOM:ELEMENT li {100B3263A3}> #<PLUMP-DOM:ELEMENT li {100B3263E3}>
+;; #<PLUMP-DOM:ELEMENT li {100B326423}> #<PLUMP-DOM:ELEMENT li {100B326463}>
+;; #<PLUMP-DOM:ELEMENT li {100B3264A3}> #<PLUMP-DOM:ELEMENT li {100B3264E3}>
+;; #<PLUMP-DOM:ELEMENT li {100B326523}> #<PLUMP-DOM:ELEMENT li {100B326563}>
+;; #<PLUMP-DOM:ELEMENT li {100B3265A3}> #<PLUMP-DOM:ELEMENT li {100B3265E3}>
+;; #<PLUMP-DOM:ELEMENT li {100B326623}> #<PLUMP-DOM:ELEMENT li {100B326663}>
+;; […]
+Wow it works ! We get here a vector of plump elements.
+ +Since it is a vector we could map over them with (map 'vector (lambda
+(elt) (…)) *).
But I’d like to easily check what those elements are. To see their textual
+content we can append (text) to our lquery form:
(lquery:$ *parsed-content* "#content" (text))
+#("License" "Editor support" "Strings" "Dates and Times" "Hash Tables"
+ "Pattern Matching / Regular Expressions" "Functions" "Loop" "Input/Output"
+ "Files and Directories" "Packages" "Macros and Backquote"
+ "CLOS (the Common Lisp Object System)" "Sockets" "Interfacing with your OS"
+ "Foreign Function Interfaces" "Threads" "Defining Systems"
+ "Using the Win32 API" "Testing" "Miscellaneous" "License" "Marco Antoniotti"
+ "Zach Beane" "Pierpaolo Bernardi" "Christopher Brown" "Frederic Brunel"
+ "Jeff Caldwell" "Bill Clementson" "Martin Cracauer" "Gerald Doussot"
+ "Paul Foley" "Jörg-Cyril
+ […]
+ "Edi Weitz" "Fernando Borretti" "lisp-lang.org" "The Awesome-cl list"
+ "The Common Lisp HyperSpec by Kent M. Pitman" "The Common Lisp UltraSpec"
+ "Practical Common Lisp by Peter Seibel"
+ "Common Lisp Recipes by Edmund Weitz, published in 2016,"
+ […]
+ "A Tutorial on Good Lisp Style by Peter Norvig and Kent Pitman"
+ "Lisp and Elements of Style by Nick Levine"
+ "Pascal Costanza’s Highly Opinionated Guide to Lisp"
+ "Loving Lisp - the Savy Programmer’s Secret Weapon by Mark Watson"
+ "FranzInc, a company selling Common Lisp and Graph Database solutions.")
+Allright, so we see we are manipulating what we want. Now to get their +href, a quick look at lquery’s doc and:
+ +(lquery:$ *parsed-content* "#content li a" (attr :href))
+;; => #("license.html" "editor-support.html" "strings.html" "dates_and_times.html"
+;; "hashes.html" "pattern_matching.html" "functions.html" "loop.html" "io.html"
+;; "files.html" "packages.html" "macros.html"
+;; "/cl-cookbook/clos-tutorial/index.html" "sockets.html" "os.html" "ffi.html"
+;; "process.html" "systems.html" "win32.html" "testing.html" "misc.html"
+;; "license.html" "mailto:xach@xach.com" "mailto:skeptomai@mac.com"
+;; "mailto:brunel@mail.dotcom.fr" "mailto:jdcal@yahoo.com"
+;; "mailto:bill_clementson@yahoo.com" "mailto:gdoussot@yahoo.com"
+;; […]
+;; "mailto:matthieu@matthieu-villeneuve.net" "mailto:edi@agharta.de"
+;; "http://lisp-lang.org/" "https://github.com/CodyReichert/awesome-cl"
+;; "http://www.lispworks.com/documentation/HyperSpec/Front/index.htm"
+;; "http://phoe.tymoon.eu/clus/doku.php" "http://www.gigamonkeys.com/book/"
+;; […]
+;; "http://www.nicklevine.org/declarative/lectures/"
+;; "http://www.p-cos.net/lisp/guide.html" "https://leanpub.com/lovinglisp/"
+;; "https://franz.com/")
+Nice, we now have the list (well, a vector) of links of the +page. We’ll now write an async program to check and validate they are +reachable.
+ +External resources:
+ + + +Async requests
+ +In this example we’ll take the list of url from above and we’ll check +if they are reachable. We want to do this asynchronously, but to see +the benefits we’ll first do it synchronously !
+ +We need a bit of filtering first to exclude the email adresses (maybe +that was doable in the CSS selector ?).
+ +We put the vector of urls in a variable:
+ +(defvar *urls* (lquery:$ *parsed-content* "#content li a" (attr :href)))
+We remove the elements that start with “mailto:”: (a quick look at the +strings page will help)
+ +(remove-if (lambda (it) (string= it "mailto:" :start1 0 :end1 (length "mailto:"))) *urls*)
+;; => #("license.html" "editor-support.html" "strings.html" "dates_and_times.html"
+;; […]
+;; "process.html" "systems.html" "win32.html" "testing.html" "misc.html"
+;; "license.html" "http://lisp-lang.org/"
+;; "https://github.com/CodyReichert/awesome-cl"
+;; "http://www.lispworks.com/documentation/HyperSpec/Front/index.htm"
+;; […]
+;; "https://franz.com/")
+Actually before writting the remove-if (which works on any sequence,
+including vectors) I tested with a (map 'vector …) to see that the
+results where indeed nil or t.
As a side note, there is a handy starts-with-p function in
+cl-strings (disclainer: that’s our lib),
+available in Quicklisp. So we could do:
(map 'vector (lambda (it) (str:starts-with-p "mailto:" it)) *urls*)
+it also has an option to ignore or respect the case.
+ +While we’re at it, we’ll only consider links starting with “http”, in +order not to write too much stuff irrelevant to web scraping:
+ +(remove-if-not (lambda (it) (string= it "http" :start1 0 :end1 (length "http"))) *) ;; note the remove-if-NOT
+Allright, we put this result in another variable:
+ +(defvar *filtered-urls* *)
+and now to the real work. For every url, we want to request it and +check that its return code is 200. We have to ignore certain +errors. Indeed, a request can timeout, be redirected (we don’t want +that) or return an error code.
+ +To be in real conditions we’ll add a link that times out in our list:
+ +(setf (aref *filtered-urls* 0) "http://lisp.org") ;; too bad indeed
+We’ll take the simple approach to ignore errors and return nil in
+that case. If all goes well, we return the return code, that should be
+200.
As we saw at the beginning, dex:get returns many values, including
+the return code. We’ll catch only this one with nth-value (instead
+of all of them with multiple-value-bind) and we’ll use
+ignore-errors, that returns nil in case of an error. We could also
+use handler-case and catch specific error types (see examples in
+dexador’s documentation) or (better yet ?) use handler-bind to catch
+any condition.
(ignore-errors has the caveat that when there’s an error, we can not +return the element it comes from. We’ll get to our ends though.)
+ +(map 'vector (lambda (it)
+ (ignore-errors
+ (nth-value 1 (dex:get it))))
+ *filtered-urls*)
+we get:
+ +#(NIL 200 200 200 200 200 200 200 200 200 200 NIL 200 200 200 200 200 200 200
+ 200 200 200 200)
+update: we could write something like the following with
+handler-case to be more flexible:
(handler-case ( <code> )
+ (error (c)
+ ( <return sthg> )))
+it works, but it took a very long time. How much time precisely ?
+with (time …):
Evaluation took:
+ 21.554 seconds of real time
+ 0.188000 seconds of total run time (0.172000 user, 0.016000 system)
+ 0.87% CPU
+ 55,912,081,589 processor cycles
+ 9,279,664 bytes consed
+21 seconds ! Obviously this synchronous method isn’t efficient. We +wait 10 seconds for links that time out. It’s time to write and +measure and async version.
+ +After installing lparallel and looking at
+its documentation, we see that the parallel
+map pmap seems to be what we
+want. And it’s only a one word edit. Let’s try:
(time (lparallel:pmap 'vector
+ (lambda (it)
+ (ignore-errors (let ((status (nth-value 1 (dex:get it)))) status)))
+ *filtered-urls*)
+;; Evaluation took:
+;; 11.584 seconds of real time
+;; 0.156000 seconds of total run time (0.136000 user, 0.020000 system)
+;; 1.35% CPU
+;; 30,050,475,879 processor cycles
+;; 7,241,616 bytes consed
+;;
+;;#(NIL 200 200 200 200 200 200 200 200 200 200 NIL 200 200 200 200 200 200 200
+;; 200 200 200 200)
+Bingo. It still takes more than 10 seconds because we wait 10 seconds +for one request that times out. But otherwise it proceeds all the http +requests in parallel and so it is much faster.
+ +Shall we get the urls that aren’t reachable, remove them from our list +and measure the execution time in the sync and async cases ?
+ +What we do is: instead of returning only the return code, we check it +is valid and we return the url:
+ +... (if (and status (= 200 status)) it) ...
+(defvar *valid-urls* *)
+we get a vector of urls with a couple of nils: indeed, I thought I
+would have only one unreachable url but I discovered another
+one. Hopefully I have pushed a fix before you try this tutorial.
But what are they ? We saw the status codes but not the urls :S We +have a vector with all the urls and another with the valid ones. We’ll +simply treat them as sets and compute their difference. This will show +us the bad ones. We must transform our vectors to lists for that.
+ +(set-difference (coerce *filtered-urls* 'list)
+ (coerce *valid-urls* 'list))
+;; => ("http://lisp-lang.org/" "http://www.psg.com/~dlamkins/sl/cover.html")
+Gotcha !
+ +BTW it takes 8.280 seconds of real time to me to check the list of +valid urls synchronously, and 2.857 seconds async.
+ +Have fun doing web scraping in CL !
+ +More helpful libraries:
+ +-
+
- we could use VCR, a store and +replay utility to set up repeatable tests or to speed up a bit our +experiments in the REPL. +
- cl-async, +carrier and others +network, parallelism and concurrency libraries to see on the +awesome-cl list, +Cliki or +Quickdocs. +
- Mockingbird is nice to mock +network requests in unit tests. +
+ 
+
+
+ // TODO
+MonkeyUser 27 06 2017
+
+ 
+
+
+ AdLitteram 30
+MonkeyUser 23 06 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ Seeking Answer
+MonkeyUser 20 06 2017
+
+
+ A system time bug with Vagrant and Make
+Posts on James Routley 19 06 2017
+
+
+ Natas wargame walkthrough, levels 1-20
+Posts on James Routley 17 06 2017
+
+
+ How to Get a File Size (and others Posix Attributes like its mtime) in Common Lisp
+Lisp journey 16 06 2017
+There is nothing built-in since CL predates the posix standard.
+ +After a look at
+Awesome CL, the
+Osicat library
+was my go-to package to look for such functionnality. There is its
+osicat-posix package indeed, even though it is undocumented
+(issue)…
Now a look at the Cookbook is ok.
+ +osicat, osicat-posix
+ +osicat-posix is included in osicat.
(ql:quickload :osicat)
+(describe (osicat-posix:stat #P"/tmp/file"))
+
+#<OSICAT-POSIX:STAT {1004F20C93}>
+ [standard-object]
+
+Slots with :INSTANCE allocation:
+ DEV = 2065
+ INO = 7349974
+ MODE = 33204
+ NLINK = 1
+ UID = 1000
+ GID = 1000
+ RDEV = 0
+ SIZE = 4304
+ BLKSIZE = 4096
+ BLOCKS = 16
+ ATIME = 1497626097
+ MTIME = 1497347216
+ CTIME = 1497347216
+; No value
+and so we can access the slots with their related functions:
+ +osicat-posix:stat-dev
+osicat-posix:stat-gid
+osicat-posix:stat-ino
+osicat-posix:stat-uid
+osicat-posix:stat-mode
+osicat-posix:stat-rdev
+osicat-posix:stat-size
+osicat-posix:stat-atime
+osicat-posix:stat-ctime
+osicat-posix:stat-mtime
+osicat-posix:stat-nlink
+osicat-posix:stat-blocks
+osicat-posix:stat-blksize
+so for example:
+ +(let ((stat (osicat-posix:stat #P"./files.md")))
+ (osicat-posix:stat-size stat)) ;; => 10629
+Trivial-file-size
+ +Now for the size there’s also the lightweight (and portable) +trivial-file-size.
+ +++ +This library exports a single function, file-size-in-octets. It returns the size of a file in bytes, using system calls when possible.
+ +The canonical way to determine the size of a file in bytes, using Common Lisp, is to open the file with an element type of (unsigned-byte 8) and then calculate the length of the stream. This is less than ideal. In most cases it would be better to get the size of the file from its metadata, using a system call.
+
The author new about osicat-posix.
+ +
+ 
+
+
+ AdLitteram 29
+MonkeyUser 16 06 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ Keep Up To Date
+MonkeyUser 13 06 2017
+
+
+ Slingshot: an interplanetary physics game
+Posts on James Routley 12 06 2017
+
+ 
+
+
+ AdLitteram 28
+MonkeyUser 09 06 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ 5 Ways to Make Django Admin Safer
+Haki Benita 08 06 2017
+With great power comes great responsibility. The more powerful your Django admin is, the safer it should be. Making a Django admin safer and more secure doesn't have to be hard - you just have to pay attention. In this article I present 5 ways to protect the Django Admin from human errors and attackers.
+
+
+ FELIZ DÍA MUNDIAL DEL MEDIO AMBIENTE!!
+Andanzas de una ambientóloga . . . 06 06 2017
+
+ 
+
+
+ Open Source Issues
+MonkeyUser 06 06 2017
+
+
+ Tail recursion for imperative programmers
+Posts on James Routley 04 06 2017
+
+
+ A guide to installing Cordova on Windows 10
+Blogs on Tom Spencer 30 05 2017
+
+
+ A guide to installing Cordova on Windows 10
+Blogs on Tom Spencer 30 05 2017
+
+ 
+
+
+ Angular vs. React
+MonkeyUser 30 05 2017
+
+
+ A guide to installing Cordova on your Mac
+Blogs on Tom Spencer 29 05 2017
+
+
+ A guide to installing Cordova on your Mac
+Blogs on Tom Spencer 29 05 2017
+
+
+
+
+ Alternativas minimalistas a Bootstrap: Frameworks CSS (III)
+Emezeta blog 27 05 2017
+
+
+ Faster, Better, Cheaper—The art of making software
+James Sinclair 26 05 2017
+
+
+ Faster, Better, Cheaper—The art of making software
+Web Development - James Sinclair 26 05 2017
+
+ 
+
+
+ AdLitteram 27
+MonkeyUser 26 05 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+
+
+ Alternativas ligeras a Bootstrap: Frameworks CSS (II)
+Emezeta blog 23 05 2017
+
+
+ Starting at the Recurse Center
+Posts on James Routley 23 05 2017
+
+ 
+
+
+ Code Review Stages
+MonkeyUser 23 05 2017
+
+
+
+
+ Alternativas a Bootstrap: Frameworks CSS (I)
+Emezeta blog 19 05 2017
+
+ 
+
+
+ AdLitteram 26
+MonkeyUser 19 05 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ Code Progression
+MonkeyUser 16 05 2017
+
+
+ ROSALIND FRANKLIN
+Andanzas de una ambientóloga . . . 12 05 2017
+
+ 
+
+
+ AdLitteram 25
+MonkeyUser 12 05 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ The Many Faces of DISTINCT in PostgreSQL
+Haki Benita 10 05 2017
+I started my programming career as an Oracle DBA. It took a few years but eventually I got fed up with the corporate world and I went about doing my own thing. After I gotten over not having proper partitions and MERGE statement, I found some nice unique features in PostgreSQL. Oddly enough, a lot of them contained the word DISTINCT.
+
+ 
+
+
+ Unit Tests Coverage Degradation
+MonkeyUser 09 05 2017
+
+ 
+
+
+ AdLitteram 24
+MonkeyUser 05 05 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ How to access url query parameters in Clack, Lucerne or Caveman
+Lisp journey 04 05 2017
+edit: I found Snooze (by +Sly and Yasnippet’s author) easier and cleaner in this regard. It also +has built-in settings to choose where to catch errors: with Slime’s +debugger, with a full stacktrace in the browser or displaying a custom +error page.
+ +If you’re using Lucerne don’t search more like I did, its
+with-params macro works with url query parameters (as well as POST
+parameters).
If you’re accessing the url hello?search=kw, this works:
@route app "/hello"
+(defview index (name)
+ (with-params (search)
+ (render-template (+index+)
+ :search search)))
+An illustration with a POST parameter from the “utweet” example:
+ +@route app (:post "/tweet")
+(defview tweet ()
+ (if (lucerne-auth:logged-in-p)
+ (let ((user (current-user)))
+ (with-params (tweet)
+ (utweet.models:tweet user tweet))
+ (redirect "/"))
+ (render-template (+index+)
+ :error "You are not logged in.")))
+The macro is implemented like this:
+ +;; https://github.com/eudoxia0/lucerne/blob/master/src/http.lisp
+(defmacro with-params (params &body body)
+ "Extract the parameters in @cl:param(param) from the @c(*request*), and bind
+them for use in @cl:param(body)."
+ `(let ,(loop for param in params collecting
+ `(,param (let ((str (parameter *request*
+ ,(intern (string-downcase
+ (symbol-name param))
+ :keyword))))
+ (if (equal str "")
+ nil
+ str))))
+ ,@body))
+For Caveman it is possible but a bit awkward and inconsistent.
+ +There’s an example for Ningle +on the related StackOverflow question.
+ +And in Clack generally ?
+ +It is only scarcely documented on Clack’s +api documentation.
+ +We can access the parameters with (clack.request:query-parameter
+lucerne:*request*). So to get the value of a given param:
(assoc "a-param" (clack.request:query-parameter lucerne:*request*) :test 'string=)
+and this returns the key and the value, so we need another cdr to get the value…
(defun query-param (param)
+ (cdr (assoc param (clack.request:query-parameter lucerne:*request*) :test #'string=)))
+See also:
+ + + +
+
+ Is There Something Like Clojure's Figwheel for interactive web dev with the browser in Common Lisp ?
+Lisp journey 04 05 2017
+Looks like there is: +trident-mode, an +“Emacs minor mode for live Parenscript interaction”, based on +skewer but: trident-mode +doesn’t seem to be used in the wild (while skewer-mode is) and I don’t +know Figwheel so all I can say is that it seems a bit different: +instead of letting us selectively evaluate and send code to the +browser, Figwheels seems to rebuild the entire project and send the +result when we write a file.
+ +I tried trident-mode quickly, it works and the author was +responsive. It offers commands and shortcuts to see the Javascript +code produced by Parenscript forms and (optionally) send them to the +browser.
+ +An example use:
+ +((@ document write)
+ (ps-html ((:a :href "foobar") "blorg")))
+to evaluate with trident-eval-dwim, which generates
document.write("<A HREF=\"foobar\">blorg</A>")
+so it uses js to insert html into the DOM. +It doesn’t leverage Skewer’s capacity to send only html.
+ +I’ll update this post if/when I can.
+ ++ + + +
++ +builds your ClojureScript code and hot loads it into the + browser as you are coding!
+
Skewer
+ +++ +Provides live interaction with JavaScript, CSS, and HTML in a web browser. Expressions are sent on-the-fly from an editing buffer to be evaluated in the browser, just like Emacs does with an inferior Lisp process in Lisp modes.
+
and we can also connect to sites on servers we don’t control.
+ +They have demo videos.
+ +
+
+ Getting started: how to install a Common Lisp development environment
+Lisp journey 03 05 2017
+or “could not find recent and easy installation steps [fixed]“.
+ +When I started I was a bit confused by old instructions (google is not +good at CL), so hopefully this post will help show up recent and easy +steps and most of all, help every CL enthousiast discover +Portacle.
+ +(and this post is editable through its Gitlab repository)
+ +Portable, a multiplatform development environment
+ +The productive Shinmera was waiting for the last details to be fixed +before showing Portacle but it was +already great. On GNU/Linux, MacOs or Windows, just download an +archive and click an icon to open Emacs ready to use for CL +development. It is that easy.
+ +It ships: Emacs (customized), the SBCL implementation, Slime (Emacs +IDE), Quicklisp (package manager) and Git. Emacs comes with a nice +theme, autocompletion in drop-downs (company-mode) and +Magit.
+ +Manual install
+ +Lisp implementation
+ +Install a CL implementation:
+ +apt-get install sbcl
+Now you can run sbcl and write lisp at the prompt:
(print "hello lisp!")
+(quit) ;; or C-d
+More are packaged for Debian and probably for your distro, notably +ECL, and note that +you can install more easily with Roswell.
+ +If you find the prompt horribly unfriendly (no history, no navigation…) use rlwrap:
+ +apt-get install rlwrap
+and now this will be slightly better:
+ +rwrap sbcl
+Even better, a slight wrapper around the SBCL REPL with readline +support (Emacs and Vim modes, history, etc): +sbcli, straightforward to use.
+ +But still, we really need an editor.
+ +Editors support
+ +You’re not bound to Emacs, there’s good support for Vim, Sublime Text +(via the SublimeREPL package) and Atom.
+ +See the Cookbook#editors.
+ +For Emacs, Slime is the de-facto +solution (there’s also the Sly fork). It is in the GNU Elpa default +Emacs package repository, so:
+ +M-x package-install RET slime RET
+(you may need a M-x package-refresh-content).
Now start Slime with M-x slime and wait a few seconds that it starts
+its backend (Swank server).
Might help:
+ +-
+
- using Emacs (and other instructions): https://www.darkchestnut.com/2017/getting-started-with-common-lisp/#using-emacs +
- http://wikemacs.org/wiki/Common_Lisp +
- Slime manual: https://common-lisp.net/project/slime/doc/html/ (see
+the Emacs menu). In very short: compile a file with
C-c C-k, +compile one function withC-c C-cand use it at the REPL.
+
Quicklisp package manager
+ +To install Quicklisp:
+ +from anywhere, download this file:
+ + wget https://beta.quicklisp.org/quicklisp.lisp
+start a Lisp and load this file:
+ +sbcl --load quicklisp.lisp
+we get in the sbcl prompt. We have one Quicklisp command to type to +install it:
+ +(quicklisp-quickstart:install)
+it will install itself in ~/quicklisp/quicklisp/.
it should output something like this, showing the basic commands:
+ +==================================================
+2,846 bytes in 0.001 seconds (2779.30KB/sec)
+Upgrading ASDF package from version 2.004 to version 2.009
+; Fetching #<URL "http://beta.quicklisp.org/dist/quicklisp.txt">
+; 0.40KB
+==================================================
+408 bytes in 0.003 seconds (132.81KB/sec)
+
+ ==== quicklisp installed ====
+
+ To load a system, use: (ql:quickload "system-name")
+
+ To find systems, use: (ql:system-apropos "term")
+
+ To load Quicklisp every time you start Lisp, use: (ql:add-to-init-file)
+
+ For more information, see http://www.quicklisp.org/beta/
+
+NIL
+Does it work ? Let’s try to install something:
+ +(ql:quickload "dexador")
+It is installed but we want to have Quicklisp available everytime we
+start sbcl. Otherwise we’d have to load the file located at
+~/quicklisp/quicklisp/setup.lisp.
Each implementation uses a startup file, like our shells, so we can
+add this into our ~/.sbclrc:
;;; The following lines added by ql:add-to-init-file:
+ #-quicklisp
+ (let ((quicklisp-init (merge-pathnames "quicklisp/setup.lisp"
+ (user-homedir-pathname))))
+ (when (probe-file quicklisp-init)
+ (load quicklisp-init)))
+To quit sbcl, (quit) or C-d.
Quicklisp is a bit different than others package managers and it is +not the only solution. That’s for another post.
+ +Starting a project
+ +I advise cl-project which, +unlike others (quickproject) also sets up tests.
+ +Now we can C-c C-k the .asd file and (ql:quickload "my-app") our
+app in the Slime REPL. But this is for another post.
Managing implementations and installing libraries in the command line: Roswell
+ +This is done together with Roswell.
+ +Roswell is in brew for MacOS, in linuxbrew, and it has a Debian package.
+ +It allows to install pinned versions of SBCL or of other +implementations (Embedable CL, Clozure CL,…) easily:
+ +ros install sbcl/1.2.14
+ros install sbcl # the latest
+ros install ccl-bin
+what’s available ?
+ +ros list versions
+change the current lisp:
+ +ros use sbcl/1.2.14
+Install scripts:
+ +ros install qlot
+Install packages:
+ +ros install dexador # http client
+and it does more to help scripting and distributing software. See its wiki !
+ +See also
+ +-
+
- a Debian package for CCL (2016): http://mr.gy/blog/clozure-cl-deb.html +
+
+ String manipulation is frustrating [fixed]
+Lisp journey 02 05 2017
+One of the first things I wanted to do in the REPL was some string +manipulation. But it was tedious.
+ +To trim whitespace, and I mean all whitespaces, we had to define
+#\Space #\Newline #\Backspace #\Tab #\Linefeed #\Page #\Return
+#\Rubout.
To concatenate two strings: either giving an unusual 'string argument to
+concatenate, like this:
(concatenate 'string "fo" "o")
+either we had to use a format construct, which is another source of
+frustration for (impatient) beginners, and sure isn’t straightforward
+and self-explanatory.
Many common stuff was split in various external libraries
+(cl-ppcre), and many common stuff was made more difficult than
+necessary (weird format construct again, entering a regexp, thus
+esaping what’s necessary, when all you want to do is simple search and
+replace, dealing with strings’ lengths and corner cases, lack of
+verbs,… see below).
And all of that with many inconsistencies (the string as first +argument, then as the last, etc).
+ +So I just joined everything in a little library, which has now more +features. Let’s see its code and its tests to learn at the canonical +way to do stuff, their shortcomings, and the library api at the same +time.
+ +I just don’t know how come this lib didn’t exist yet.
+ +str
+
+You can install it with
+ +(ql:quickload "str")
+See on https://github.com/vindarel/cl-str.
+ +Package definition
+ +(in-package #:asdf-user)
+
+(defsystem :str
+ :source-control (:git "git@github.com:vindarel/cl-s.git")
+ :description "Modern, consistent and terse Common Lisp string manipulation library."
+ :depends-on (:prove :cl-ppcre) ;; <= depends only on cl-ppcre.
+ :components ((:file "str"))
+ )
+Trim
+ +(defvar *whitespaces* '(#\Space #\Newline #\Backspace #\Tab
+ #\Linefeed #\Page #\Return #\Rubout))
+
+(defun trim-left (s)
+ "Remove whitespaces at the beginning of s. "
+ (string-left-trim *whitespaces* s))
+
+(defun trim-right (s)
+ "Remove whitespaces at the end of s."
+ (string-right-trim *whitespaces* s))
+
+
+(defun trim (s)
+ (string-trim *whitespaces* s))
+
+Concat
+ +(defun concat (&rest strings)
+ "Join all the string arguments into one string."
+ (apply #'concatenate 'string strings))
+Join
+ +Snippets on the old cookbook or stackoverflow advised to use a
+format construct. Which is weird, and causes problems if your
+separator contains the ~ symbol.
(defun join (separator strings)
+ (let ((separator (replace-all "~" "~~" separator)))
+ (format nil
+ (concatenate 'string "~{~a~^" separator "~}")
+ strings)))
+Now:
+ +(is "foo~bar"
+ (join "~" '("foo" "bar")))
+Split
+ +cl-ppcre takes a regexp, but we don’t need this for the basic cases
+of split. And disabling this regexp was not straightforward:
(defun split (separator s &key omit-nulls)
+ "Split s into substring by separator (cl-ppcre takes a regex, we do not)."
+ ;; cl-ppcre:split doesn't return a null string if the separator appears at the end of s.
+ (let* ((val (concat s
+ (string separator)
+ ;; so we need an extra character, but not the user's.
+ (if (string-equal separator #\x) "y" "x")))
+ (res (butlast (cl-ppcre:split (cl-ppcre:quote-meta-chars (string separator)) val))))
+ (if omit-nulls
+ (remove-if (lambda (it) (empty? it)) res)
+ res)))
+Now: (split "." "foo.bar") just works.
Repeat
+ +(defun repeat (count s)
+ "Make a string of S repeated COUNT times."
+ (let ((result nil))
+ (dotimes (i count)
+ (setf result (cons s result)))
+ (apply #'concat result)))
+Replace-all
+ +This required to use cl-ppcre and one switch of it to avoid regexps.
+ +(defun replace-all (old new s)
+ "Replace `old` by `new` in `s`. Arguments are not regexs."
+ (let* ((cl-ppcre:*allow-quoting* t)
+ (old (concatenate 'string "\\Q" old))) ;; treat metacharacters as normal.
+ (cl-ppcre:regex-replace-all old s new)))
+starts-with? start string
+ +The Lisp way was to check if the beginning of “string” contains +“start”, taking its length, dealing with corner cases,…
+ +(defun starts-with? (start s &key (ignore-case nil))
+ "Return t if s starts with the substring 'start', nil otherwise."
+ (when (>= (length s) (length start))
+ (let ((fn (if ignore-case #'string-equal #'string=)))
+ (funcall fn s start :start1 0 :end1 (length start)))))
+
+;; An alias:
+;; Serapeum defines a "defalias".
+(setf (fdefinition 'starts-with-p) #'starts-with?)
+
+(defun ends-with? (end s &key (ignore-case nil))
+ "Return t if s ends with the substring 'end', nil otherwise."
+ (when (>= (length s) (length end))
+ (let ((fn (if ignore-case #'string-equal #'string=)))
+ (funcall fn s end :start1 (- (length s) (length end))))))
+
+(setf (fdefinition 'ends-with-p) #'ends-with?)
+Usage illustrated by the tests:
+ +(subtest "starts-with?"
+ (ok (starts-with? "foo" "foobar") "default case")
+ (ok (starts-with? "" "foo") "with blank start")
+ (ok (not (starts-with? "rs" "")) "with blank s")
+ (ok (not (starts-with? "foobar" "foo")) "with shorter s")
+ (ok (starts-with? "" "") "with everything blank")
+ (ok (not (starts-with? "FOO" "foobar")) "don't ignore case")
+ (ok (starts-with-p "f" "foo") "starts-with-p alias")
+ (ok (starts-with? "FOO" "foobar" :ignore-case t) "ignore case"))
+Predicates: empty? blank?
+ +There was no built-in to make those differences.
+ +(defun empty? (s)
+ "Is s nil or the empty string ?"
+ (or (null s) (string-equal "" s)))
+
+(defun emptyp (s)
+ "Is s nil or the empty string ?"
+ (empty? s))
+
+(defun blank? (s)
+ "Is s nil or only contains whitespaces ?"
+ (or (null s) (string-equal "" (trim s))))
+
+(defun blankp (s)
+ "Is s nil or only contains whitespaces ?"
+ (blank? s))
+words, unwords, lines, unlines
+ +Classic stuff:
+ +(defun words (s &key (limit 0))
+ "Return list of words, which were delimited by white space. If the optional limit is 0 (the default), trailing empty strings are removed from the result list (see cl-ppcre)."
+ (if (not s)
+ nil
+ (cl-ppcre:split "\\s+" (trim-left s) :limit limit)))
+
+(defun unwords (strings)
+ "Join the list of strings with a whitespace."
+ (join " " strings))
+
+(defun lines (s &key omit-nulls)
+ "Split the string by newline characters and return a list of lines."
+ (split #\NewLine s :omit-nulls omit-nulls))
+
+(defun unlines (strings)
+ "Join the list of strings with a newline character."
+ (join (make-string 1 :initial-element #\Newline) strings))
+Substring
+ +The builtin subseq is much poorer compared to what we have in other languages.
Take Python, we can do:
+ +"foo"[:-1] # negative index and starting from the end
+"foo"[0:100] # end is too large, thus it returns the entire array.
+This was not possible with subseq, it throws a condition. Nothing
+found in Alexandria or other helper libraries.
(defun substring (start end s)
+ "Return the substring of `s' from `start' to `end'.
+
+It uses `subseq' with differences:
+- argument order, s at the end
+- `start' and `end' can be lower than 0 or bigger than the length of s.
+
+- for convenience `end' can be nil or t to denote the end of the string.
+"
+ (let* ((s-length (length s))
+ (end (cond
+ ((null end) s-length)
+ ((eq end t) s-length)
+ (t end))))
+ (setf start (max 0 start))
+ (if (> start s-length)
+ ""
+ (progn
+ (setf end (min end s-length))
+ (when (< end (- s-length))
+ (setf end 0))
+ (when (< end 0)
+ (setf end (+ s-length end)))
+ (if (< end start)
+ ""
+ (subseq s start end))))))
+Usage:
+ +(subtest "substring"
+ (is "abcd" (substring 0 4 "abcd") "normal case")
+ (is "ab" (substring 0 2 "abcd") "normal case substing")
+ (is "bc" (substring 1 3 "abcd") "normal case substing middle")
+ (is "" (substring 4 4 "abcd") "normal case")
+ (is "" (substring 0 0 "abcd") "normal case")
+ (is "d" (substring 3 4 "abcd") "normal case")
+ (is "abcd" (substring 0 t "abcd") "end is t")
+ (is "abcd" (substring 0 nil "abcd") "end is nil")
+ (is "abcd" (substring 0 100 "abcd") "end is too large")
+ (is "abc" (substring 0 -1 "abcd") "end is negative")
+ (is "b" (substring 1 -2 "abcd") "end is negative")
+ (is "" (substring 2 1 "abcd") "start is bigger than end")
+ (is "" (substring 0 -100 "abcd") "end is too low")
+ (is "" (substring 100 1 "abcd") "start is too big")
+ (is "abcd" (substring -100 4 "abcd") "start is too low")
+ (is "abcd" (substring -100 100 "abcd") "start and end are too low and big")
+ (is "" (substring 100 -100 "abcd") "start and end are too big and low")
+ )
+See also
+ +and afterwards I saw +cl-strings which +does help but can have its shortcomings.
+ +The Cookbook is updated: https://lispcookbook.github.io/cl-cookbook/strings.html
+ +
+ 
+
+
+ Shady Logic Gates
+MonkeyUser 02 05 2017
+
+
+ All You Need To Know About Prefetching in Django
+Haki Benita 28 04 2017
+A rundown of all the ways you can use Prefetch to speed up queries in Django.
+
+ 
+
+
+ AdLitteram 23
+MonkeyUser 28 04 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ Prevención de riesgos laborales PRL
+Andanzas de una ambientóloga . . . 24 04 2017
+
+ 
+
+
+ QA Engineer - Bed Shopping
+MonkeyUser 24 04 2017
+
+ 
+
+
+ AdLitteram 22
+MonkeyUser 21 04 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ Easter Eggs
+MonkeyUser 18 04 2017
+
+
+ Why is there no generic operators ?
+Lisp journey 14 04 2017
+TLDR; because the object system came afterwards (and it was not the + intention to make CL entirely object oriented).
+ +As a CL enthousiast coming from Python, I feel the pain not to have +generic or polymorphic operators but having to learn about many +specialized operators instead. Why is it so and are there solutions ?
+ ++ +
I asked on SO.
+ +In CL, there are many operators to check for equality that depend on
+the data type: =, string-equal, char=, then equal, eql and
+whatnot, so on for other data types, and the same for comparison
+operators. There are no generic and extendible operators. For our
+own types, we define its own functions.
As a reminder for those equality operators: equal does work on
+integers, strings and characters and equalp also works for lists,
+vectors and hash tables an other Common Lisp types but objects. See
+the SO answers
+for precisions and experienced lispers debatting of the inner
+subtilities and traps of those functions.
The language has mechanisms to create generics though, see +generics (defgeneric, defmethod) +as described in Practical Common Lisp.
+ +There have been work in that direction (https://common-lisp.net/project/cdr/document/8/cleqcmp.html) but no library as of today.
+ +It’s a recurrent concern, also +this blog post +(“Not a monad tutorial”, great serie) points to this. The guy moved +to Clojure, for other reasons too of course, where there are only one (or +two?) equality operators.
+ +So it seems that the reason is mostly historical, the object system +(CLOS) appearing afterwards. Of course the generics would be +slower. But how much slower ? I really don’t care, as a beginner and +for web stuff.
+ +++ +Generic CLOS functions were added several years after CL was originally designed (82-84). The variant with CLOS was widely published with CLtL2 (1990) and then ANSI CL. The language was only slightly updated. It was not the intention to make Common Lisp fully object oriented. Also performance of CLOS for relatively low-level functions is kind of problematic. Dylan, which is something like Scheme + CLOS - s-expression syntax, did this: it defines more of the language in terms of generic functions. [Rainer Joswig on SO]
+
The CL21 way
+ +Fortunately CL21 introduces (more) generic
+operators, particularly for sequences it defines length, append,
+setf, getf, first, rest, subseq, replace, take, drop, fill,
+take-while, drop-while, last, butlast, find-if, search,
+remove-if, delete-if, reverse, reduce, sort, split,
+join, remove-duplicates, every, some, map, sum (and some
+more). Those should work at least for strings, lists,
+vectors and extend the new abstract-sequence type.
Now CL21 is something worth presenting and debatting in another post.
+ +More:
+ + + +
+
+ Example of interactively changing the current executed Lisp code in the debugger
+Lisp journey 14 04 2017
+The awesome example we will read comes from a comment by user lispm +inside a discussion on this reddit thread: +https://www.reddit.com/r/programming/comments/65ct5j/a_pythonist_finds_a_new_home_at_clojure_land/.
+ +The article it discusses is a
+“Not a monad tutorial”
+post, where the interviewee is experienced in C++, Java, Javascript and Python and
+turns into Clojure. He wrote about his first impressions with Common
+Lisp
+here,
+where he raises usual concerns that I agree with but IMO that stay
+supercifial (“not readable” because of stuff like (format t
+"~{~{~a:~10t~a~%~}~%~}" *db*), “huge operators set”, “macros look
+promising”…).
Here starts the discussion.
+ ++ +
dzecniv On Common Lisp, I agree with the criticisms except
++ +the code was very difficult to read
+
I find it very easy, always well expressed, with concise
+functions. And I find Clojure’s harder, with more
+[, { and the same number of other symbols (#, *).
Anyway, I’m in the process of trying to go from python to CL. +The CL ecosystem is quite good nowadays (equivalents of pip, venvs, pyenv, implementations (even +for the JVM or iOS), CI, sphinx, readthedocs, wsgi, setup.py,,…), it’s moving, we can do quite a +lot (awesome list), +it has unique features but yeah, the ecosystem is tiny compared to +clojure’s…
+ +ps: interested ? http://lisp-lang.org/ !
+ +lispm
++ +tiny compared to clojure
+
In many ways is it much broader than Clojure, since there is much more +choice. Interpreters, compilers, native code compilers, batch +compilers, compilers targeting +C/LLVM/JVM/ARM/ARM64/x86/x86-64/SPARC64/POWER/…
+ +Clojure on the JVM uses a relatively simple and not very user-friendly +compiler to the JVM. No Interpreter. No mixed use of interpreted and +compiled code. Functions need to be declared before used. Error +messages are exposing the underlying JVM. No TCO. No images. Slow +startup.
+ +The Roomba cleans your home with a CL program.
+ +MagicMurderBagYT
++ +No Interpreter.
+
Hol up. What about the REPL?
+ +lispm
That’s not an interpreter. A REPL is not the same as a Lisp +interpreter. REPL means read eval print loop. EVAL can be implemented +by a compiler or an interpreter. Common Lisp has both and mixed +implementations with both compiler and interpreter.
+ +A Lisp interpreter is executing Lisp code directly. Clojure does not have an Interpreter.
+ +++ +https://clojure.org/reference/evaluation
+ +Clojure has no interpreter.
+
Example in LispWorks, which uses the Interpreter in the REPL:
+ +CL-USER 29 > (let ((f (lambda (a b)
+ (+ (prog1 2 (break)) ; we have a break here
+ (* a b)))))
+ (funcall f 2 3))
+
+Break.
+ 1 (continue) Return from break.
+ 2 (abort) Return to level 0.
+ 3 Return to top loop level 0.
+
+Type :b for backtrace or :c <option number> to proceed.
+Type :bug-form "<subject>" for a bug report template or :? for other options.
+As you see Lisp comes with a sub-repl in the break. The sub-repl is +just another repl, but in the context of the break. The break could be +done by the debugger when it sees an error or by user code - as above.
+ +Now we ask the interpreter for the current lambda expression:
+ +CL-USER 30 : 1 > :lambda
+(LAMBDA (A B) (+ (PROG1 2 (BREAK)) (* A B)))
+Above is actually Lisp data. Code as data.
+ +Now I’m changing the + function in the code to be expt, +exponentiation. To be clear: I’m changing in the debugger the current +executed Lisp function on the Lisp level. We take the third element of +the list, and then the first one of that. This is the + symbol. We +change it to be expt. * holds the last evaluation result of the REPL.
+ +CL-USER 31 : 1 > (setf (first (third *)) 'expt)
+EXPT
+Then I’m restarting the current stack frame:
+ +CL-USER 32 : 1 > :res
+We get another break, which we just continue from:
+ +Break.
+ 1 (continue) Return from break.
+ 2 (abort) Return to level 0.
+ 3 Return to top loop level 0.
+
+Type :b for backtrace or :c <option number> to proceed.
+Type :bug-form "<subject>" for a bug report template or :? for other options.
+
+CL-USER 33 : 1 > :c 1
+64 ; we computed 2^(2*3) instead of 2+(2*3)
+What did we see? We saw that the interpreter uses actual Lisp +code. Lisp code we can change with Lisp code in the debugger.
+ +A second example.
+ +What can we do with that for debugging? Well, we can for example write +our own evaluation tracer. The Evaluator prints each expression and +its result nicely indented, while walking the expression tree and +evaluating subexpressions. Remember: this is now user-level code. The +example is from CLtL2. You will also see that LispWorks can freely mix +compiled and interpreted functions. The function COMPILE takes a +function name and compiles its Lisp code to machine code.
+ +CL-USER 1 > (defvar *hooklevel* 0)
+*HOOKLEVEL*
+
+CL-USER 2 > (defun hook (x)
+ (let ((*evalhook* 'eval-hook-function))
+ (eval x)))
+HOOK
+
+CL-USER 3 > (compile 'hook)
+HOOK
+NIL
+NIL
+
+CL-USER 4 > (defun eval-hook-function (form &rest env)
+ (let ((*hooklevel* (+ *hooklevel* 1)))
+ (format *trace-output* "~%~V@TForm: ~S"
+ (* *hooklevel* 2) form)
+ (let ((values (multiple-value-list
+ (evalhook form
+ #'eval-hook-function
+ nil
+ env))))
+ (format *trace-output* "~%~V@TValue:~{ ~S~}"
+ (* *hooklevel* 2) values)
+ (values-list values))))
+EVAL-HOOK-FUNCTION
+
+CL-USER 5 > (compile 'eval-hook-function)
+EVAL-HOOK-FUNCTION
+NIL
+NIL
+Now we can trace the evaluation of expressions on the Lisp level:
+ +CL-USER 6 > (hook '(cons (floor *print-base* 2) 'b))
+
+ Form: (CONS (FLOOR *PRINT-BASE* 2) (QUOTE B))
+ Form: (FLOOR *PRINT-BASE* 2)
+ Form: *PRINT-BASE*
+ Value: 10
+ Form: 2
+ Value: 2
+ Value: 5 0
+ Form: (QUOTE B)
+ Value: B
+ Value: (5 . B)
+(5 . B)
+dzecniv
that’s an awesome example and tutorial that I’d love to see on a blog +post or just a gist or something for further reference and better +archiving, this will be buried too quickly on reddit !
+ ++ +
So here it is.
+ +Epilogue: the Roomba robot vacuums.
+ +
+ 
+
+
+ AdLitteram 21
+MonkeyUser 14 04 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ Steps to reproduce
+MonkeyUser 11 04 2017
+
+
+ Persistent Undo in Vim
+Jovica Ilic 07 04 2017
+As you already saw in the chapter on Undo/redo, Vim is pretty powerful when it comes to these features. However, there’s one more feature which I didn’t mention, as it takes a bit of configuration. In Vim, like in every other text editor, you can perform undo/redo in your current session. Once the session is... Continue reading
+The post Persistent Undo in Vim appeared first on Jovica Ilic.
+ +
+ 
+
+
+ AdLitteram 20
+MonkeyUser 07 04 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ MARGARITA SALAS
+Andanzas de una ambientóloga . . . 04 04 2017
+
+ 
+
+
+ Different Perspectives
+MonkeyUser 04 04 2017
+
+ 
+
+
+ AdLitteram 19
+MonkeyUser 31 03 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ How to Turn Django Admin Into a Lightweight Dashboard
+Haki Benita 30 03 2017
+Django Admin is a powerful tool for managing data in your app. However, it was not designed with summary tables and charts in mind. Luckily, the developers of Django Admin made it easy for us to customize. We are going to turn Django Admin into a dashboard by adding a chart and a summary table.
+
+ 
+
+
+ Product Stages
+MonkeyUser 28 03 2017
+
+ 
+
+
+ Comparing Reagent to React.js and Vue.js for dynamic tabular data
+(iterate think thoughts) 26 03 2017
+I recently ran across a comparison of React.js to Vue.js for rendering dynamic tabular data, and I got curious to see how Reagent would stack up against them.
The benchmark simulates a view of football games represented by a table. Each row in the table represents the state of a particular game. The game states are updated once a second triggering UI repaints.
I structured the application similarly to the way that React.js version was structured in the original benchmark. The application has a football.data namespace to handle the business logic, and a football.core namespace to render the view.
Implementing the Business Logic
Let's start by implementing the business logic in the football.data namespace. First, we'll need to provide a container to hold the state of the games. To do that we'll create a Reagent atom called games:
(ns football.data
+ (:require [reagent.core :as reagent]))
+
+(defonce games (reagent/atom nil))
+Next, we'll add a function to generate the fake players:
(defn generate-fake-player []
+ {:name (-> js/faker .-name (.findName))
+ :effort-level (rand-int 10)
+ :invited-next-week? (> (rand) 0.5)})
+You can see that we're using JavaScript interop to leverage the Faker.js library for generating the player names. One nice aspect of working with ClojureScript is that JavaScript interop tends to be seamless as seen in the code above.
Now that we have a way to generate the players, let's add a function to generate fake games:
(defn generate-fake-game []
+ {:id (-> js/faker .-random (.uuid))
+ :clock 0
+ :score {:home 0 :away 0}
+ :teams {:home (-> js/faker .-address (.city))
+ :away (-> js/faker .-address (.city))}
+ :outrageous-tackles 0
+ :cards {:yellow 0 :read 0}
+ :players (mapv generate-fake-player (range 4))})
+With the functions to generate the players and the games in place, we'll now add a function to generate a set of initial game states:
(defn generate-games [game-count]
+ (reset! games (mapv generate-fake-game (range game-count))))
+The next step is to write the functions to update the games and players to simulate the progression of the games. This code translates pretty much directly from the JavaScript version:
(defn maybe-update [game prob path f]
+ (if (< (rand-int 100) prob)
+ (update-in game path f)
+ game))
+
+(defn update-rand-player [game idx]
+ (-> game
+ (assoc-in [:players idx :effort-level] (rand-int 10))
+ (assoc-in [:players idx :invited-next-week?] (> (rand) 0.5))))
+
+(defn update-game [game]
+ (-> game
+ (update :clock inc)
+ (maybe-update 5 [:score :home] inc)
+ (maybe-update 5 [:score :away] inc)
+ (maybe-update 8 [:cards :yellow] inc)
+ (maybe-update 2 [:cards :red] inc)
+ (maybe-update 10 [:outrageous-tackles] inc)
+ (update-rand-player (rand-int 4))))
+The last thing we need to do is to add the functions to update the game states at a specified interval. The original code uses Rx.js to accomplish this, but it's just as easy to do using the setTimeout function with Reagent:
(defn update-game-at-interval [interval idx]
+ (swap! games update idx update-game)
+ (js/setTimeout update-game-at-interval interval interval idx))
+
+(def event-interval 1000)
+
+(defn update-games [game-count]
+ (dotimes [i game-count]
+ (swap! games update i update-game)
+ (js/setTimeout #(update-game-at-interval event-interval i)
+ (* i event-interval))))
+The update-games function updates the state of each game, then sets up a timeout for the recurring updates using the update-game-at-interval function.
Implementing the View
We're now ready to write the view portion of the application. We'll start by referencing the football.data namespace in the football.core namespace:
(ns football.core
+ (:require
+ [football.data :as data]
+ [reagent.core :as reagent]))
+Next, we'll write the components to display the players and the games:
(defn player-component [{:keys [name invited-next-week? effort-level]}]
+ [:td
+ [:div.player
+ [:p.player__name
+ [:span name]
+ [:span.u-small (if invited-next-week? "Doing well" "Not coming again")]]
+ [:div {:class-name (str "player__effort "
+ (if (< effort-level 5)
+ "player__effort--low"
+ "player__effort--high"))}]]])
+
+(defn game-component [game]
+ [:tr
+ [:td.u-center (:clock game)]
+ [:td.u-center (-> game :score :home) "-" (-> game :score :away)]
+ [:td.cell--teams (-> game :teams :home) "-" (-> game :teams :away)]
+ [:td.u-center (:outrageous-tackles game)]
+ [:td
+ [:div.cards
+ [:div.cards__card.cards__card--yellow (-> game :cards :yellow)]
+ [:div.cards__card.cards__card--red (-> game :cards :red)]]]
+ (for [player (:players game)]
+ ^{:key player}
+ [player-component player])])
+
+(defn games-component []
+ [:tbody
+ (for [game @data/games]
+ ^{:key game}
+ [game-component game])])
+
+(defn games-table-component []
+ [:table
+ [:thead
+ [:tr
+ [:th {:width "50px"} "Clock"]
+ [:th {:width "50px"} "Score"]
+ [:th {:width "200px"} "Teams"]
+ [:th "Outrageous Tackles"]
+ [:th {:width "100px"} "Cards"]
+ [:th {:width "100px"} "Players"]
+ [:th {:width "100px"} ""]
+ [:th {:width "100px"} ""]
+ [:th {:width "100px"} ""]
+ [:th {:width "100px"} ""]]]
+ [games-component]])
+You can see that HTML elements in Reagent components are represented using Clojure vectors and maps. Since s-expressions cleanly map to HTML, there's no need to use an additional DSL for that. You'll also notice that components can be nested within one another same way as plain HTML elements.
Noe thing to note is that the games-component dereferences the data/games atom using the @ notation. Dereferencing simply means that we'd like to view the current state of a mutable variable.
Reagent atoms are reactive, and listeners are created when the atoms are dereferenced. Whenever the state of the atom changes, any components that are observing the atom will be notified of the change.
In our case, changes in the state of the games atom will trigger the games-component function to be evaluated. The function will pass the current state of the games down to its child components, and this will trigger any necessary repaints in the UI.
Finally, we have a bit of code to create the root component represented by the home-page function, and initialize the application:
(defn home-page []
+ [games-table-component])
+
+(defn mount-root []
+ (reagent/render [home-page] (.getElementById js/document "app")))
+
+(def game-count 50)
+
+(defn init! []
+ (data/generate-games game-count)
+ (data/update-games game-count)
+ (mount-root))
+We now have a naive implementation of the benchmark using Reagent. The entire project is available on GitHub. Next, let's take a look at how it performs.
Profiling with Chrome
When we profile the app in Chrome, we'll see the following results:
Here are the results for React.js and Vue.js running in the same environment for comparison:
As you can see, the naive Reagent version spends about double the time scripting compared to React.js, and about four times as long rendering.
The reason is that we're dereferencing the games atom at top level. This forces the top level component to be reevaluated whenever the sate of any game changes.
Reagent provides a mechanism for dealing with this problem in the form of cursors. A cursor allows subscribing to changes at a specified path within the atom. A component that dereferences a cursor will only be updated when the data the cursor points to changes. This allows us to granularly control what components will be repainted when a particular piece of data changes in the games atom. Let's update the view logic as follows:
(defn player-component [player]
+ [:td
+ [:div.player
+ [:p.player__name
+ [:span (:name @player)]
+ [:span.u-small
+ (if (:invited-next-week? @player)
+ "Doing well" "Not coming again")]]
+ [:div {:class-name (str "player__effort "
+ (if (< (:effort-level @player) 5)
+ "player__effort--low"
+ "player__effort--high"))}]]])
+
+(defn game-component [game]
+ [:tr
+ [:td.u-center (:clock @game)]
+ [:td.u-center (-> @game :score :home) "-" (-> @game :score :away)]
+ [:td.cell--teams (-> @game :teams :home) "-" (-> @game :teams :away)]
+ [:td.u-center (:outrageous-tackles @game)]
+ [:td
+ [:div.cards
+ [:div.cards__card.cards__card--yellow (-> @game :cards :yellow)]
+ [:div.cards__card.cards__card--red (-> @game :cards :red)]]]
+ (for [idx (range (count (:players @game)))]
+ ^{:key idx}
+ [player-component (reagent/cursor game [:players idx])])])
+
+(def game-count 50)
+
+(defn games-component []
+ [:tbody
+ (for [idx (range game-count)]
+ ^{:key idx}
+ [game-component (reagent/cursor data/games [idx])])])
+
+(defn games-table-component []
+ [:table
+ [:thead
+ [:tr
+ [:th {:width "50px"} "Clock"]
+ [:th {:width "50px"} "Score"]
+ [:th {:width "200px"} "Teams"]
+ [:th "Outrageous Tackles"]
+ [:th {:width "100px"} "Cards"]
+ [:th {:width "100px"} "Players"]
+ [:th {:width "100px"} ""]
+ [:th {:width "100px"} ""]
+ [:th {:width "100px"} ""]
+ [:th {:width "100px"} ""]]]
+ [games-component]])
+
+(defn home-page []
+ [games-table-component])
+The above version creates a cursor for each game in the games-components. The game-component in turn creates a cursor for each player. This way only the components that actually need updating end up being rendered as the state of the games is updated. Let's profile the application again to see how much impact this has on its performance:
The performance of the Reagent code using cursors now looks similar to that of the Vue.js implementation. You can see the entire source for the updated version here.
Conclusion
In this post we saw that ClojureScript with Reagent provides a compelling alternative to JavaScript offerings such as React.js and Vue.js.
Reagent allows writing succinct solutions that perform as well as those implemented using native JavaScript libraries. It also provides us with tools to intuitively reason about what parts of the view are going to be updated.
Likewise, we get many benefits by simply switching from using JavaScript to ClojureScript.
For example, We already saw that we didn't need any additional syntax, such as JSX, to represent HTML elements. Since HTML templates are represented using regular data structures, they follows the same rules as any other code. This allows us to transform them just like we would any other data in our project.
In general, I find ClojureScript to be much more consistent and less noisy than equivalent JavaScript code. Consider the implementation of the updateGame function in the original JavaScript version:
function updateGame(game) {
+ game = game.update("clock", (sec) => sec + 1);
+
+ game = maybeUpdate(5, game, () => game.updateIn(["score", "home"], (s) => s + 1));
+ game = maybeUpdate(5, game, () => game.updateIn(["score", "away"], (s) => s + 1));
+
+ game = maybeUpdate(8, game, () => game.updateIn(["cards", "yellow"], (s) => s + 1));
+ game = maybeUpdate(2, game, () => game.updateIn(["cards", "red"], (s) => s + 1));
+
+ game = maybeUpdate(10, game, () => game.update("outrageousTackles", (t) => t + 1));
+
+ const randomPlayerIndex = randomNum(0, 4);
+ const effortLevel = randomNum();
+ const invitedNextWeek = faker.random.boolean();
+
+ game = game.updateIn(["players", randomPlayerIndex], (player) => {
+ return player.set("effortLevel", effortLevel).set("invitedNextWeek", invitedNextWeek);
+ });
+
+ return game;
+}
+Compare it with the equivalent ClojureScript code:
(defn update-rand-player [game idx]
+ (-> game
+ (assoc-in [:players idx :effort-level] (rand-int 10))
+ (assoc-in [:players idx :invited-next-week?] (> (rand) 0.5))))
+
+(defn update-game [game]
+ (-> game
+ (update :clock inc)
+ (maybe-update 5 [:score :home] inc)
+ (maybe-update 5 [:score :away] inc)
+ (maybe-update 8 [:cards :yellow] inc)
+ (maybe-update 2 [:cards :red] inc)
+ (maybe-update 10 [:outrageous-tackles] inc)
+ (update-rand-player (rand-int 4))))
+ClojureScript version has a lot less syntactic noise, and I find this has direct impact on my ability to reason about the code. The more quirks there are, the more likely I am to misread the intent. Noisy syntax results in situations where code looks like it's doing one thing, while it's actually doing something subtly different.
Another advantage is that ClojureScript is backed by immutable data structures by default. My experience is that immutability is crucial for writing large maintainable projects, as it allows safely reasoning about parts of the code in isolation.
Since immutability is pervasive as opposed to opt-in, it allows for tooling to be designed with it in mind. For example, Figwheel plugin relies on this property to provide live hot reloading in the browser.
Finally, ClojureScript compiler can do many optimizations, such as dead code elimination, that are difficult to do with JavaScript. I highly recommend the Now What? talk by David Nolen that goes into more details regarding this.
Overall, I'm pleased to see that ClojureScript and Reagent perform so well when stacked up against native JavaScript libraries. It's hard to overstate the fact that a ClojureScript library built on top of React.js can outperform React.js itself.
+
+
+ JavaScript. But less iffy.
+James Sinclair 24 03 2017
+
+
+ JavaScript. But less iffy.
+Web Development - James Sinclair 24 03 2017
+
+ 
+
+
+ AdLitteram 18
+MonkeyUser 24 03 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ Testing Vs Production Environment
+MonkeyUser 21 03 2017
+
+ 
+
+
+ AdLitteram 17
+MonkeyUser 17 03 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+
+
+ 10 juegos Indie gratuitos estilo pixel art
+Emezeta blog 16 03 2017
+
+ 
+
+
+ Trivial Bug
+MonkeyUser 16 03 2017
+
+ 
+
+
+ Shared DB
+MonkeyUser 14 03 2017
+
+
+ CARNAVALES Y RESIDUOS
+Andanzas de una ambientóloga . . . 13 03 2017
+
+ 
+
+
+ AdLitteram 16
+MonkeyUser 10 03 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+Suggested by: @jaivalis
+
+
+ 
+
+
+ Bugshots
+MonkeyUser 07 03 2017
+
+ 
+
+
+ AdLitteram 15
+MonkeyUser 03 03 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ SHA-1 Collision
+MonkeyUser 28 02 2017
+
+ 
+
+
+ Static vs. Dynamic Linking
+MonkeyUser 27 02 2017
+
+ 
+
+
+ AdLitteram 14
+MonkeyUser 24 02 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ Mastering Vim Quickly: Introduction
+Jovica Ilic 23 02 2017
+This post presents a chapter from my upcoming book Mastering Vim Quickly: From WTF to OMG in no time Introduction There’s so much you want to do in life, and so little time. The story of our modern lives. Take a moment and consider how many things you want to learn. Since you’re reading... Continue reading
+The post Mastering Vim Quickly: Introduction appeared first on Jovica Ilic.
+ +
+ 
+
+
+ Tales of RegEx: #42
+MonkeyUser 21 02 2017
+
+
+ How to Test Django Signals Like a Pro
+Haki Benita 17 02 2017
+Django signals are extremely useful for decoupling modules. They allow a low-level Django app to send events for other apps to handle without creating a direct dependency. Signals are easy to set up, but harder to test. In this article we implement a context manager for testing Django signals, step by step.
+
+ 
+
+
+ AdLitteram 13
+MonkeyUser 17 02 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+ 
+
+
+ DevOps Life
+MonkeyUser 16 02 2017
+
+
+ Instapaper Service Fully Restored
+Instapaper 14 02 2017
+After suffering from an extended outage on Wednesday, February 9 at 12:30PM PT through Thursday, February 10 at 7:30PM PT, we brought the Instapaper service back up with limited access to archives as a short-term solution while we worked to restore the service completely.
Today at 1AM PT we completely restored the Instapaper service, including access to all archives. We performed the restoration without losing any of your older articles, changes made to more recent articles or articles saved after recovering from the outage.
We apologize for the extended downtime and the time it took to regain access to your complete archives. Instapaper has operated as a high availability service over the last nine years without many hiccups. The root cause of this outage was both difficult to predict and prevent, and the nature of the outage is extremely rare and unlikely to recur. We appreciate your patience during this time.
We’d like to thank the Pinterest Site Reliability Engineering team for guiding us through the recovery, and the Amazon Relational Database Service team for working with us throughout the weekend to dramatically expedite the recovery process.
Lastly, if you’re interested in a more detailed overview of the issue that caused the outage and our process to recover the service, you can learn more on our Engineering Blog.
– Instapaper Team
+
+ 
+
+
+ Hotfix
+MonkeyUser 14 02 2017
+
+
+ ¿Han sido los Reyes Magos Sostenibles?
+Andanzas de una ambientóloga . . . 13 02 2017
+
+
+ MUJERES Y CIENCIA
+Andanzas de una ambientóloga . . . 13 02 2017
+
+
+
+
+ Navegadores web: ¿Cuál es el mejor navegador para mi?
+Emezeta blog 12 02 2017
+
+
+ Instapaper Restored, Access to Archives Limited
+Instapaper 10 02 2017
+As we shared earlier today, Instapaper is experiencing an extended outage. After 31 hours of downtime, we were able to rebuild a database instance to get Instapaper back online! In the interest of coming back up as soon as possible, this instance only has the last six weeks of articles. For now, anything you’ve saved since December 20, 2016 is accessible.
We’re working on getting the rest of your articles restored, but wanted to give you access to your most recently saved articles in the meantime. Again, there hasn’t been any data loss. The full database exports are taking much longer than anticipated.
We’re aiming to get the full archives available by next Friday, February 17 at the latest. We appreciate your patience and understanding in the interim.
– Instapaper Team
+ 
+
+
+ AdLitteram 12
+MonkeyUser 10 02 2017
+Welcome to AdLitteram. The challenge is to guess the programming term that is represented in the image. (use the commenting section if you think you know the answer)
+ +
+
+ JavaScript Without Loops
+James Sinclair 09 02 2017
+
+
+ JavaScript Without Loops
+Web Development - James Sinclair 09 02 2017
+
+
+ Extended Outage
+Instapaper 09 02 2017
+Yesterday, February 8th, at 12:30PM PT Instapaper suffered from an outage that has extended through this morning.
After spending multiple hours on the phone with our cloud service provider, it appears we hit a system limit for our hosted database that’s preventing new articles from being saved. At this time, our only option is to export all data from our old database and import it into a new one. We expect the service to be fully recovered today, February 9.
We pride ourselves on being a reliable service with minimal downtime (we were up for 99.93% of 2016), and know many of you rely on Instapaper every day. We apologize that this issue has resulted in an extended period of downtime.
We assure you we haven’t lost any data. While you may not have been able to save articles during the outage, anything you’ve already saved to Instapaper is safe. We appreciate your patience while we work diligently to get it resolved.
- Instapaper Team
+
+ 
+
+
+ Programming languages as humans
+MonkeyUser 07 02 2017
+
+
+
+
+ State of Common Lisp Web Development - an overview
+Lisp journey 05 02 2017
+Caution: this is a draft. I take notes and write more in other resources (the Cookbook, my blog).
+ +update july, 5th 2019: I put this content into the Cookbook: https://lispcookbook.github.io/cl-cookbook/web.html, fixing a long-standing request.
+ +new post: why and how to live-reload one’s running web application: https://lisp-journey.gitlab.io/blog/i-realized-that-to-live-reload-my-web-app-is-easy-and-convenient/
+ +new project skeleton: lisp-web-template-productlist: Hunchentoot + easy-routes + Djula templates + Bulma CSS + a Makefile to build the project
+ +See also the +Awesome CL list.
+ +Information is at the moment scarce and spread appart, Lisp web +frameworks and libraries evolve and take different approaches.
+ +I’d like to know what’s possible, what’s lacking, see how to +quickstart everything, see code snippets and, most of all, see how to +do things that I couldn’t do before such as hot reloading, building +self-contained executables, shipping a multiplatform web app.
+ + + +Table of Contents
+ +-
+
- Web application environments
+
+
-
+
- Clack, Lack +
+ - Web frameworks + + +
- Tasks
+
+
-
+
- Accessing url parameters +
- Session an cookies +
- Data storage +
- SQL + + +
- Forms + + +
- Debugging +
- Testing +
- Misc + + +
+ - Templating engines
+
+
-
+
- HTML-based +
- Lisp-based +
+ - Javascript + + +
- Shipping + + +
- Deployment + +
Web application environments
+ +Clack, Lack
+ +Clack is to Lisp what WSGI is to Python. However it is mostly undocumented and not as battle-proofed as Hunchentoot.
+ +Web frameworks
+ +Hunchentoot
+ +The de-facto web server, with the best documentation (cough looking old cough), +the most websites on production. Lower level than a web framework +(defining routes seems weird at first). I think worth knowing.
+ +Its terminology is different from what we are used to (“routes” are +not called routes but we create handlers), part I don’t know why and +part because the Lisp image-based development allows for more, and +thus needs more terminology. For example, we can run two applications +on different URLs on the same image.
+ +https://edicl.github.io/hunchentoot/
+ +edit: here’s a modern looking page: https://digikar99.github.io/common-lisp.readthedocs/hunchentoot/
+ +Caveman
+ +A popular web framework, or so it seems by the github stars, written by a super-productive lisper, with nice documentation for basic +stuff but lacking for the rest, based on Clack (webserver interface, +think Python’s WSGI), uses Hunchentoot by default.
+ +I feel like basic functions are too cumbersome (accessing url parameters).
+ +https://github.com/fukamachi/caveman
+ +Snooze
+ +By the maintainer of Sly, Emacs’ Yasnippet,…
+ +Defining routes is like defining functions. Built-in features that are +available as extensions in Clack-based frameworks (setting to get a +stacktrace on the browser, to fire up the debugger or to return a +404,…). Definitely worth exploring.
+ +https://github.com/joaotavora/snooze
+ +Radiance
+ +Radiance, with extensive tutorial and existing apps.
+ +It doesn’t look like a web framework to me. It has ready-to-use components:
+ +-
+
- admin page (but what does it do?) +
- auth system +
- user: provide user accounts and permissions +
- image hosting +
- there is an email marketing system in development… +
cl-rest-server
+ + + +++ +a library for writing REST Web APIs in Common Lisp.
+
Features: validation via schemas, Swagger support, authentication, logging, caching, permission checking…
+ +It seems complete, it is maintained, the author seems to be doing web development in CL for a living. Note to self: I want to interview him.
+ +Wookie
+ +https://github.com/orthecreedence/wookie
+ +An asynchronous web server, by an impressive lisper, who built many async +libraries. Used for the Turtl api +backend. Dealing with async brings its own set of problems (how will +be debugging ?).
+ +Nice api to build routes, good documentation: http://wookie.lyonbros.com/
+ +Weblocks (solving the Javascript problem)
+ +Weblocks allows to create dynamic pages without a line of JavaScript, +all in Lisp. It was started years ago and it saw a large update and +refactoring lately.
+ +It isn’t the easy path to web development in CL but there’s great potential IMO.
+ +It doesn’t do double data binding as in modern JS frameworks. But new projects are being developed…
+ +See our presentation below.
+ +http://40ants.com/weblocks/quickstart.html
+ +Tasks
+ +Accessing url parameters
+ +It is easy and well explained with Hunchentoot or easy-routes in the Cookbook.
Lucerne has a nice
+with-params macro that makes accessing post or url query parameters a breeze:
@route app (:post "/tweet")
+(defview tweet ()
+ (if (lucerne-auth:logged-in-p)
+ (let ((user (current-user)))
+ (with-params (tweet)
+ (utweet.models:tweet user tweet))
+ (redirect "/"))
+ (render-template (+index+)
+ :error "You are not logged in.")))
++ +
Snooze’s way is simple and +lispy: we define routes like methods and parameters as keys:
+ +(defroute lispdoc (:get :text/* name &key (package :cl) (doctype 'function))
+ ...
+matches /lispdoc, /lispdoc/foo and /lispdoc/foo?package=arg.
+ +
On the contrary, I find Caveman’s and Ningle’s ways cumbersome.
+ +Ningle:
+ +(setf (ningle:route *app* "/hello/:name")
+ #'(lambda (params)
+ (format nil "Hello, ~A" (cdr (assoc "name" params :test #'string=)))))
+++ +The above controller will be invoked when you access to “/hello/Eitaro” or “/hello/Tomohiro”, and then (cdr (assoc “name” params :test #‘string=)) will be “Eitaro” and “Tomohiro”.
+
and it doesn’t say about query parameters. I had to ask:
+ +(assoc "the-query-param" (clack.request:query-parameter lucerne:*request*) :test 'string=)
+Caveman:
+ +++ +Parameter keys contain square brackets (”[” & “]”) will be parsed as structured parameters. You can access the parsed parameters as _parsed in routers.
+
(defroute "/edit" (&key _parsed)
+ (format nil "~S" (cdr (assoc "person" _parsed :test #'string=))))
+;=> "((\"name\" . \"Eitaro\") (\"email\" . \"e.arrows@gmail.com\") (\"birth\" . ((\"year\" . 2000) (\"month\" . 1) (\"day\" . 1))))"
+Session an cookies
+ +Data storage
+ +SQL
+ +Mito works for MySQL, Postgres +and SQLite3 on SBCL and CCL.
+ +https://lispcookbook.github.io/cl-cookbook/databases.html
+ +We can define models with a regular class which has a mito:dao-table-class :metaclass:
(defclass user ()
+ ((name :col-type (:varchar 64)
+ :initarg :name
+ :accessor user-name)
+ (email :col-type (:varchar 128)
+ :initarg :email
+ :accessor user-email))
+ (:metaclass mito:dao-table-class)
+ (:unique-keys email))
+We create the table with ensure-table-exists:
(ensure-table-exists 'user)
+;-> ;; CREATE TABLE IF NOT EXISTS "user" (
+; "id" BIGSERIAL NOT NULL PRIMARY KEY,
+; "name" VARCHAR(64) NOT NULL,
+; "email" VARCHAR(128),
+; "created_at" TIMESTAMP,
+; "updated_at" TIMESTAMP
+; ) () [0 rows] | MITO.DAO:ENSURE-TABLE-EXISTS
+Persistent datastores
+ +Migrations
+ +Mito has migrations support and +DB schema versioning for MySQL, Postgres and SQLite3, on SBCL and +CCL. Once we have changed our model definition, we have commands to +see the generated SQL and to apply the migration.
+ +We inspect the SQL: (suppose we just added the email field into the user class above)
(mito:migration-expressions 'user)
+;=> (#<SXQL-STATEMENT: ALTER TABLE user ALTER COLUMN email TYPE character varying(128), ALTER COLUMN email SET NOT NULL>
+; #<SXQL-STATEMENT: CREATE UNIQUE INDEX unique_user_email ON user (email)>)
+and we can apply the migration:
+ +(mito:migrate-table 'user)
+;-> ;; ALTER TABLE "user" ALTER COLUMN "email" TYPE character varying(128), ALTER COLUMN "email" SET NOT NULL () [0 rows] | MITO.MIGRATION.TABLE:MIGRATE-TABLE
+; ;; CREATE UNIQUE INDEX "unique_user_email" ON "user" ("email") () [0 rows] | MITO.MIGRATION.TABLE:MIGRATE-TABLE
+;-> (#<SXQL-STATEMENT: ALTER TABLE user ALTER COLUMN email TYPE character varying(128), ALTER COLUMN email SET NOT NULL>
+; #<SXQL-STATEMENT: CREATE UNIQUE INDEX unique_user_email ON user (email)>)
+Crane advertises automatic
+migrations, i.e. it would run them after a C-c C-c. Unfortunately Crane has
+some issues, it doesn’t work with sqlite yet and the author is busy
+elsewhere. It didn’t work for me at first try.
Let’s hope the author comes back to work on this in a near future.
+ +Forms
+ +There are a few libraries, see the awesome-cl list. At least one is well active.
+ +Debugging
+ +On an error we are usually dropped into the interactive debugger by default.
+ +Snooze gives options:
+ +-
+
- use the debugger, +
- print the stacktrace in the browser (like clack-errors below, but built-in), +
- display a custom 404. +
clack-errors. Like a Flask +or Django stacktrace in the browser. For Caveman, Ningle and family.
+ +++ +By default, when Clack throws an exception when rendering a page, the server waits for the response until it times out while the exception waits in the REPL. This isn’t very useful. So now there’s this.
+
It prints the stacktrace along with some request details on the +browser. Can return a custom error page in production.
+ +++ +Are you tired of jumping to your web browser every time you need to test your work in Clack? Clack-pretend will capture and replay calls to your clack middleware stack. When developing a web application with clack, you will often find it inconvenient to run your code from the lisp REPL because it expects a clack environment, including perhaps, cookies or a logged-in user. With clack-pretend, you can run prior web requests from your REPL, moving development back where it belongs.
+
Testing
+ +Testing with a local DB: example of a testing macro.
+ +We would use envy to switch configurations.
+ +Misc
+ +Oauth, Job queues, etc
+ +Templating engines
+ +HTML-based
+ +Djula: as Django +templates. Good documentation. Comes by default in Lucerne and Caveman.
+ +We also use a dot to access attributes of dict-like variables (plists, +alists, hash-tables, arrays and CLOS objects), such a feature being +backed by the access +library.
+ +We wanted once to use structs and didn’t find how to it directly in +Djula, so we resorted in a quick helper function to transform the +struct in an alist.
+ +Defining custom template filters is straightforward in Djula, really a +breeze compared to Django.
+ +Eco - a mix of html with lisp expressions.
+ +Truncated example:
+ +<body>
+ <% if posts %>
+ <h1>Recent Posts</h1>
+ <ul id="post-list">
+ <% loop for (title . snippet) in posts %>
+ <li><%= title %> - <%= snippet %></li>
+ <% end %>
+ </ul>
+ ...
+Lisp-based
+ +I prefer the semantics of +Spinneret over cl-who. It +also has more features (like embeddable markdown, warns on malformed html, and more).
+ +Javascript
+ +Parenscript
+ +++ +Parenscript is a translator from an extended subset of Common Lisp to JavaScript. Parenscript code can run almost identically on both the browser (as JavaScript) and server (as Common Lisp). +Parenscript code is treated the same way as Common Lisp code, making the full power of Lisp macros available for JavaScript. This provides a web development environment that is unmatched in its ability to reduce code duplication and provide advanced meta-programming facilities to web developers.
+
https://common-lisp.net/project/parenscript/
+ +JSCL
+ +++ +A Lisp-to-Javascript compiler bootstrapped from Common Lisp and executed from the browser.
+
https://github.com/jscl-project/jscl
+ +https://t-cool.github.io/jscl-playground/
+ +Ajax
+ +Is it possible to write Ajax-based pages only in CL?
+ +The case Webblocks - Reblocks, 2017
+ +Weblocks is an “isomorphic” web frameworks that solves the “Javascript +problem”. It allows to write the backend and an interactive client +interface in Lisp, without a line of Javascript, in our usual Lisp +development environment.
+ +The framework evolves around widgets, that are updated server-side +and are automatically redisplayed with transparent ajax calls on the +client.
+ +It is being massively refactored, simplified, rewritten and documented +since 2017. See the new quickstart:
+ +http://40ants.com/weblocks/quickstart.html
+ +Writing a dynamic todo-app resolves in:
+ +-
+
- defining a widget class for a task: +
(defwidget task ()
+ ((title
+ :initarg :title
+ :accessor title)
+ (done
+ :initarg :done
+ :initform nil
+ :accessor done)))
+-
+
- doing the same for a list of tasks: +
(defwidget task-list ()
+ ((tasks
+ :initarg :tasks
+ :accessor tasks)))
+-
+
- saying how to render these widgets in html by extending the
rendermethod:
+
(defmethod render ((task task))
+ "Render a task."
+ (with-html
+ (:span (if (done task)
+ (with-html
+ (:s (title task)))
+ (title task)))))
+
+(defmethod render ((widget task-list))
+ "Render a list of tasks."
+ (with-html
+ (:h1 "Tasks")
+ (:ul
+ (loop for task in (tasks widget) do
+ (:li (render task))))))
+-
+
- telling how to initialize the Weblocks app: +
(defmethod weblocks/session:init ((app tasks))
+ (declare (ignorable app))
+ (let ((tasks (make-task-list "Make my first Weblocks app"
+ "Deploy it somewhere"
+ "Have a profit")))
+ (make-instance 'task-list :tasks tasks)))
+-
+
- and then writing functions to interact with the widgets, for example adding a task: +
(defmethod add-task ((task-list task-list) title)
+ (push (make-task title)
+ (tasks task-list))
+ (update task-list))
+Adding an html form and calling the new add-task function:
(defmethod render ((task-list task-list))
+ (with-html
+ (:h1 "Tasks")
+ (loop for task in (tasks task-list) do
+ (render task))
+ (with-html-form (:POST (lambda (&key title &allow-other-keys)
+ (add-task task-list title)))
+ (:input :type "text"
+ :name "title"
+ :placeholder "Task's title")
+ (:input :type "submit"
+ :value "Add"))))
+Shipping
+ +Building
+ +We can build an executable also for web apps. That makes for a simple deployment process.
+ +We can even get a Lisp REPL and interact with the running web app, +including installing new Quicklisp dependencies. That’s quite +incredible, and it’s very useful, if not to hot-reload a web app +(which I do anyways), at least to reload a user configuration file.
+ +This is the general way:
+ +(sb-ext:save-lisp-and-die #p"name-of-executable" :toplevel #'main :executable t)
+we need a step more for web apps:
+ +(defun main ()
+ ;; with bordeaux-threads. Also sb-ext: join-thread, thread-name, list-all-threads.
+ (bt:join-thread (find-if (lambda (th)
+ (search "hunchentoot" (bt:thread-name th)))
+ (bt:all-threads))))
+I can now build my web app, send it to my VPS and see it live.
+ +When I run it, Hunchentoot stays listening at the foreground:
+ +$ ./my-webapp
+Hunchentoot server is started.
+Listening on localhost:9003.
+I need to put it in the background (C-z bg), or use a tmux session
+(tmux, then C-b d to detach it).
To be complete, you’ll notice that we can not C-c our running app,
+we get trapped into the debugger (which responds only to C-z and
+kill). As with any command line, we have to catch the corresponding
+signal. We also stop our app. See
+our cl-torrents tutorial
+on how to build command-line applications.
(defun main ()
+ (start-app :port 9003)
+ ;; with bordeaux-threads
+ (handler-case (bt:join-thread (find-if (lambda (th)
+ (search "hunchentoot" (bt:thread-name th)))
+ (bt:all-threads)))
+ (#+sbcl sb-sys:interactive-interrupt
+ #+ccl ccl:interrupt-signal-condition
+ #+clisp system::simple-interrupt-condition
+ #+ecl ext:interactive-interrupt
+ #+allegro excl:interrupt-signal
+ () (progn
+ (format *error-output* "Aborting.~&")
+ (clack:stop *server*)
+ (uiop:quit 1)) ;; portable exit, included in ASDF, already loaded.
+ ;; for others, unhandled errors (we might want to do the same).
+ (error (c) (format t "Woops, an unknown error occured:~&~a~&" c)))))
+See also how to daemonize an application (below in Deployment).
+ +To see:
+ +-
+
- a Debian package for every Quicklisp system: http://margaine.com/2015/12/22/quicklisp-packagecloud-debian-packages.html. +
Multiplatform delivery with Electron (Ceramic)
+ +Ceramic makes all the work for us.
+ +It is as simple as this:
+ +;; Load Ceramic and our app
+(ql:quickload '(:ceramic :our-app))
+
+;; Ensure Ceramic is set up
+(ceramic:setup)
+(ceramic:interactive)
+
+;; Start our app (here based on the Lucerne framework)
+(lucerne:start our-app.views:app :port 8000)
+
+;; Open a browser window to it
+(defvar window (ceramic:make-window :url "http://localhost:8000/"))
+
+;; start Ceramic
+(ceramic:show-window window)
+and we can ship this on Linux, Mac and Windows.
+ +More:
+ +++ +Ceramic applications are compiled down to native code, ensuring both performance and enabling you to deliver closed-source, commercial applications.
+
(so no need to minify our JS)
+ +with one more line:
+ +(ceramic.bundler:bundle :ceramic-hello-world
+ :bundle-pathname #p"/home/me/app.tar")
+Copying resources...
+Compiling app...
+Compressing...
+Done!
+#P"/home/me/app.tar"
+This last line was buggy for us.
+ +Deployment
+ +When you build a self-contained binary, deployment gets easy.
+ +Radiance’s tutorial talks about deployment. https://github.com/Shirakumo/radiance-tutorial/blob/master/Part%207.md
+ +Running the app on a web server
+ +Manually
+ +sbcl --load <my-app> --eval (start-my-app)
+For example, a run Makefile target:
run:
+ sbcl --load my-app.asd \
+ --eval '(ql:quickload :my-app)' \
+ --eval '(my-app:start-app)' ;; given this function starts clack or hunchentoot.
+this keeps sbcl in the foreground. Can use tmux or just C-z bg to put it in background.
Then, we need of a task supervisor, that will restart our app on failures, start it after a reboot, handle logging. See the section below and example projects (such as Quickutil).
+ +with Clack
+ +$ clackup app.lisp
+Hunchentoot server is started.
+Listening on localhost:5000.
+with Docker
+ +So we have various implementations ready to use: sbcl, ecl, ccl… with Quicklisp well configured.
+ +https://lispcookbook.github.io/cl-cookbook/testing.html#gitlab-ci
+ +On Heroku
+ +See heroku-buildpack-common-lisp and the Awesome CL#deploy section.
+ +Daemonizing, restarting in case of crashes, handling logs (Systemd)
+ +Generally, this depends on your system. But most GNU/Linux distros now come with Systemd. Write a service file like this:
+ +$ /etc/systemd/system/my-app.service
+[Unit]
+Description=stupid simple example
+
+[Service]
+WorkingDirectory=/path/to/your/app
+ExecStart=sbcl --load run.lisp # your command
+Type=simple
+Restart=always
+RestartSec=10
+run a command to start it:
+ +sudo systemctl start my-app.service
+a command to check its status:
+ +systemctl status my-app.service
+Systemd handles logging. We write to stdout or stderr, it writes logs:
+ +journalctl -f -u my-app.service
+and it handles crashes and restarts the app:
+ +Restart=always
+and it can start the app after a reboot:
+ +[Install]
+WantedBy=basic.target
+to enable it:
+ +sudo systemctl enable my-app.service
+Debugging SBCL error: ensure_space: failed to allocate n bytes
+ +If you get this error with SBCL on your server:
+ +mmap: wanted 1040384 bytes at 0x20000000, actually mapped at 0x715fa2145000
+ensure_space: failed to allocate 1040384 bytes at 0x20000000
+(hint: Try "ulimit -a"; maybe you should increase memory limits.)
+then disable ASLR:
+ +sudo bash -c "echo 0 > /proc/sys/kernel/randomize_va_space"
+Connecting to a remote Swank server
+ +Little example here: http://cvberry.com/tech_writings/howtos/remotely_modifying_a_running_program_using_swank.html.
+ +It defines a simple function that prints forever:
+ +;; a little common lisp swank demo
+;; while this program is running, you can connect to it from another terminal or machine
+;; and change the definition of doprint to print something else out!
+;; (ql:quickload '(:swank :bordeaux-threads))
+
+(require :swank)
+(require :bordeaux-threads)
+
+(defparameter *counter* 0)
+
+(defun dostuff ()
+ (format t "hello world ~a!~%" *counter*))
+
+(defun runner ()
+ (bt:make-thread (lambda ()
+ (swank:create-server :port 4006)))
+ (format t "we are past go!~%")
+ (loop while t do
+ (sleep 5)
+ (dostuff)
+ (incf *counter*)))
+
+(runner)
+On our server, we run it with
+ +sbcl --load demo.lisp
+we do port forwarding on our development machine:
+ +ssh -L4006:127.0.0.1:4006 username@example.com
+this will securely forward port 4006 on the server at example.com to +our local computer’s port 4006 (swanks accepts connections from +localhost).
+ +We connect to the running swank with M-x slime-connect, typing in
+port 4006.
We can write new code:
+ +(defun dostuff ()
+ (format t "goodbye world ~a!~%" *counter*))
+(setf *counter* 0)
+and eval it as usual with M-x slime-eval-region for instance. The output should change.
There are more pointers on CV Berry’s page.
+ +Hot reload
+ +When we run the app as a script we get a Lisp REPL, so we can +hot-reload the running web app. Here we demonstrate a recipe to update +it remotely.
+ +Example taken from Quickutil.
+ +It has a Makefile target:
+ +hot_deploy:
+ $(call $(LISP), \
+ (ql:quickload :quickutil-server) (ql:quickload :swank-client), \
+ (swank-client:with-slime-connection (conn "localhost" $(SWANK_PORT)) \
+ (swank-client:slime-eval (quote (handler-bind ((error (function continue))) \
+ (ql:quickload :quickutil-utilities) (ql:quickload :quickutil-server) \
+ (funcall (symbol-function (intern "STOP" :quickutil-server))) \
+ (funcall (symbol-function (intern "START" :quickutil-server)) $(start_args)))) conn)) \
+ $($(LISP)-quit))
+It has to be run on the server (a simple fabfile command can call this
+through ssh). Beforehand, a fab update has run git pull on the
+server, so new code is present but not running. It connects to the
+local swank server, loads the new code, stops and starts the app in a
+row.
+ +
(yes that currently helps, thanks!)
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Thanks Lionel
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Thanks /u/spartaboy
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Thanks @brampatelski
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Thanks @brampatelski
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