I have the following code for lex and yacc. I am getting kind of extra values in the printed statement can anyone tell. whats wrong with the code?
Lex code:
%{
#include <stdio.h>
#include "y.tab.h"
%}
%%
[ \t] ;
[+-] { yylval=yytext; return Sym;}
(s|c|t)..x { yylval=yytext; return Str;}
[a-zA-Z]+ { printf("Invalid");}
%%
int yywrap()
{
return 1;
}
yacc code:
%{
#include<stdio.h>
%}
%start exps
%token Sym Str
%%
exps: exps exp
| exp
;
exp : Str Sym Str {printf("%s",$1); printf("%s",$2); printf("%s",$3);}
;
%%
int main (void)
{
while(1){
return yyparse();
}
}
yyerror(char *err) {
fprintf(stderr, "%s\n",err);
}
Input: sinx+cosx
output: sinx+cosx+cosxcosx
look at the output of the code!!!