From 517fe14667f0e5e62df8835c23eeaf97d8e04fbd Mon Sep 17 00:00:00 2001
From: Ron Pedde <ron@pedde.com>
Date: Tue, 2 Aug 2005 03:17:22 +0000
Subject: [PATCH] what will eventually be the smart playlist parser

---
 src/parser-driver.c | 19 ++++++++++
 src/parser.mk       |  8 ++++
 src/smart-parser.c  | 91 +++++++++++++++++++++++++++++++++++++++++++++
 src/smart-parser.h  | 16 ++++++++
 4 files changed, 134 insertions(+)
 create mode 100644 src/parser-driver.c
 create mode 100644 src/parser.mk
 create mode 100644 src/smart-parser.c
 create mode 100644 src/smart-parser.h

diff --git a/src/parser-driver.c b/src/parser-driver.c
new file mode 100644
index 00000000..0c71ac62
--- /dev/null
+++ b/src/parser-driver.c
@@ -0,0 +1,19 @@
+/*
+ * Test harness for the parser
+ */
+
+#include <stdio.h>
+#include "smart-parser.h"
+
+int main(int argc, char *argv[]) {
+    PARSETREE pt;
+
+    printf("Parsing %s\n",argv[1]);
+
+    pt=sp_init();
+    sp_parse(pt,argv[1]);
+    sp_dispose(pt);
+
+    printf("Done!\n");
+    return 0;
+}
diff --git a/src/parser.mk b/src/parser.mk
new file mode 100644
index 00000000..72dde0a8
--- /dev/null
+++ b/src/parser.mk
@@ -0,0 +1,8 @@
+CC=gcc
+CFLAGS := $(CFLAGS) -g -I/sw/include -DHAVE_CONFIG_H -I. -I.. -Wall
+TARGET=parser
+OBJECTS=parser-driver.o smart-parser.o err.o
+
+$(TARGET):	$(OBJECTS)
+	$(CC) -o $(TARGET) $(LDFLAGS) $(OBJECTS)
+
diff --git a/src/smart-parser.c b/src/smart-parser.c
new file mode 100644
index 00000000..b88b9277
--- /dev/null
+++ b/src/smart-parser.c
@@ -0,0 +1,91 @@
+/*
+ * $Id$
+ *
+ * This is really two parts -- the lexer and the parser.  Converting
+ * a parse tree back to a format that works with the database backend
+ * is left to the db backend.
+ *
+ * Oh, and this is called "smart-parser" because it parses terms for
+ * specifying smart playlists, not because it is particularly smart.  :)
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "err.h"
+
+typedef struct tag_parsetree {
+    char *term;
+    int token;
+    int next_token;
+} PARSESTRUCT, *PARSETREE;
+
+#define SP_TOK_EOF     0
+
+
+
+/**
+ * set up the initial parse tree
+ * 
+ * @returns opaque parsetree struct
+ */
+PARSETREE sp_init(void) {
+    PARSETREE ptree;
+
+    ptree = (PARSETREE)malloc(sizeof(PARSESTRUCT));
+    if(!ptree) 
+	DPRINTF(E_FATAL,L_PARSE,"Alloc error\n");
+
+    memset(ptree,0,sizeof(PARSESTRUCT));
+    return ptree;
+}
+
+/**
+ * parse a term or phrase into a tree.
+ *
+ * @param tree parsetree previously created with sp_init
+ * @param term term or phrase to parse
+ * @returns 1 if successful, 0 if not
+ */
+int sp_parse(PARSETREE tree, char *term) {
+    tree->term = strdup(term); /* will be destroyed by parsing */
+    while(sp_scan(tree)) {
+	if(tree->token == SP_TOK_EOF)
+	    return 1; /* valid tree! */
+
+	/* otherwise, keep scanning until done or error */
+    }
+}
+
+/**
+ * dispose of an initialized tree
+ *
+ * @param tree tree to dispose
+ * @returns 1
+ */
+int sp_dispose(PARSETREE tree) {
+    if(tree->term)
+	free(tree->term);
+
+    free(tree);
+    return 1;
+}
+
+
+/**
+ * if there was an error in a previous action (parsing?)
+ * then return that error to the client.  This does not 
+ * clear the error condition -- multiple calls to sp_geterror
+ * will return the same value.
+ *
+ * memory handling is done on the smart-parser side.
+ *
+ * @param tree tree that generated the last error
+ * @returns text of the last error
+ */
+char *sp_geterror(PARSETREE tree) {
+    return "blah";
+}
+
diff --git a/src/smart-parser.h b/src/smart-parser.h
new file mode 100644
index 00000000..a335a8c5
--- /dev/null
+++ b/src/smart-parser.h
@@ -0,0 +1,16 @@
+/*
+ * $Id$
+ */
+
+#ifndef _SMART_PARSER_H_
+#define _SMART_PARSER_H_
+
+typedef void* PARSETREE;
+
+extern PARSETREE sp_init(void);
+extern int sp_parse(PARSETREE *tree, char *term);
+extern int sp_dispose(PARSETREE tree);
+extern char *sp_geterror(PARSETREE tree);
+
+#endif /* _SMART_PARSER_H_ */
+