YACC program for Binary to Decimal Conversion

Problem: Write YACC program for Binary to Decimal Conversion.

Explanation:
Yacc (for “yet another compiler compiler.”) is the standard parser generator for the Unix operating system. An open source program, yacc generates code for the parser in the C programming language. The acronym is usually rendered in lowercase but is occasionally seen as YACC or Yacc.

Examples:

Input: 0101
Output: 5

Input: 1101
Output: 13

Input: 111001
Output: 57

Input: 1111111
Output: 127

Input: 100111000
Output: 312 

Lexical Analyzer Source Code:

%{
  /* Definition section */
  #include<stdio.h>
  #include<stdlib.h>
  #include"y.tab.h"
  extern int yylval;
%}

/* Rule Section */
 %%
 0 {yylval=0;return ZERO;}
 1 {yylval=1;return ONE;}

 [ \t] {;}
 \n return 0;
 . return yytext[0];
%%


int yywrap()
 {
  return 1;
 }

Parser Source Code:

%{
  /* Definition section */
  #include<stdio.h>
  #include<stdlib.h>
  void yyerror(char *s);
%}
%token ZERO ONE

/* Rule Section */
%%
N: L {printf("\n%d", $$);}
L: L B {$$=$1*2+$2;}
| B {$$=$1;}
B:ZERO {$$=$1;}
|ONE {$$=$1;};
%%

//driver code
int main()
{
 while(yyparse());
}

yyerror(char *s)
{
 fprintf(stdout, "\n%s", s);
}

Output: