1 /*
2 * This file is part of flex.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE.
22 */
23
24 /* Accepts html-like input.
25 How to compile:
26 bison --defines --output-file="parser.c" --name-prefix="test" parser.y
27 */
28 %parse-param { void* scanner }
29 %lex-param { void* scanner }
30 %{
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include "config.h"
35 #include "bison_yylval_parser.h"
36 #include "bison_yylval_scanner.h"
37
38 #define YYERROR_VERBOSE 1
39
40 int yyerror(void* scanner, const char* msg);
41
42 /* A dummy function. A check against seg-faults in yylval->str. */
process_text(char * s)43 static int process_text(char* s) {
44 int total =0;
45 while(*s) {
46 total += (int) *s;
47 ++s;
48 }
49 return total;
50 }
51
52
53 %}
54
55 %pure-parser
56
57 %union {
58 long unused;
59 char * str;
60 }
61
62 %token <str> TAGNAME TEXT
63 %token LT
64 %token GT
65 %token LTSLASH "</"
66
67 %%
68
69 html:
70 TEXT { process_text($1); free($1);}
71 | starttag html endtag
72 | html TEXT { process_text($2); free($2);}
73 | html starttag html endtag
74 ;
75
76 starttag: LT TAGNAME GT { process_text($2); free($2);} ;
77 endtag: LTSLASH TAGNAME GT { process_text($2);free($2);} ;
78 %%
79
80 int yyerror(void* scanner, const char* msg) {
81 (void)scanner;
82 fprintf(stderr,"%s\n",msg);
83 return 0;
84 }
85