Created
November 27, 2017 12:30
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Sample lex+yacc program
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| %{ | |
| #include <stdlib.h> | |
| #include "y.tab.h" | |
| %} | |
| %% | |
| [0-9]+ { | |
| yylval = atoi(yytext); | |
| return ENTIER; | |
| } | |
| [-+\n] return *yytext; | |
| [ \t] ; /* skip whitespace */ | |
| . yyerror("invalid character"); | |
| %% |
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| %{ | |
| #include <stdio.h> | |
| #include <string.h> | |
| void yyerror(const char *str) | |
| { | |
| fprintf(stderr,"Erreur: %s\n",str); | |
| } | |
| yywrap() | |
| { | |
| return 1; | |
| } | |
| main() | |
| { | |
| return yyparse(); | |
| } | |
| %} | |
| %start program | |
| %token ENTIER | |
| %left '+' | |
| %% | |
| program: | |
| program expr '\n' { printf("%d\n", $2); } | |
| | | |
| ; | |
| expr: | |
| ENTIER { $$ = $1;} | |
| | expr '+' expr { $$ = $1 + $3; } | |
| ; | |
| %% |
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