Flex i Bison/Kalkulator z dynamicznymi zmiennymi - lekser

/* Lex input */
%{
    #include <stdlib.h>
    #include <stdio.h>
    #include "y.tab.h"
    void yyerror(char* );
    int varindex(char* );
%}

%%

[ \t]+ ;
(([0-9]+(\.[0-9]*)?)|([0-9]*\.[0-9]+)) { 
          yylval.dval = atof(yytext); return DOUBLE; }
[-+*/=] { return *yytext; }
"("     { return *yytext; }
")"     { return *yytext; }
[a-z][a-z0-9]*  { 
          yylval.ivar = varindex(yytext); return NAME; }
\n      { return *yytext;}
.       { char msg[25];
          sprintf(msg,"%s <%s>","invalid character",yytext);
          yyerror(msg); }

%%

int yywrap(void) 
{
    return 1;
}