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 40int yyerror(void* scanner, const char* msg); 41 42/* A dummy function. A check against seg-faults in yylval->str. */ 43static 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 69html: 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 76starttag: LT TAGNAME GT { process_text($2); free($2);} ; 77endtag: LTSLASH TAGNAME GT { process_text($2);free($2);} ; 78%% 79 80int yyerror(void* scanner, const char* msg) { 81 (void)scanner; 82 fprintf(stderr,"%s\n",msg); 83 return 0; 84} 85