assigning ASCII values to variables in bison

I want my parser to handle case like:

a='A'; // a should be set with ASCII(A) i.e 65

My token declaration looks like :

%union {
  double dval;
  char *symbol;
}

%token <symbol> SYMBOL_NAME
%token <dval> NUMBER
%token BINARY
%token OCTAL
%token DECIMAL
%token HEXADECIMAL
%token UNSIGNED
%token <symbol>CHAR
%token SHORT
%token INT
%token LONG

my statement declaration looks like:

statement:      ';'
|       expression             { setp($1); print_universal_base($1, 0); }
|       expression BINARY      { setp($1); print_universal_base($1, 2); }
|       expression OCTAL       { setp($1); print_universal_base($1, 8); }
|       expression DECIMAL     { setp($1); print_universal_base($1, 10); }
|       expression HEXADECIMAL { setp($1); print_universal_base($1, 16); }

my expression declaration looks like this:

expression:     expression ',' expression { $$ = $3; }
|       SY开发者_开发技巧MBOL_NAME '=' expression { if(assign_value($1, $3, &$$)) YYABORT; }
|       NUMBER { $$ = $1; }
|       '\'' CHAR '\'' { if(set_ASCII($2, &$$)) YYABORT; }

shouldn't

'\'' CHAR '\'' { if(set_ASCII($2, &$$)) YYABORT; } 

handle my case? as I see that when I input like

a='A'; 

set_ASCII() is not being called. what is incorrect here?

---

what is incorrect here?

The answer almost certainly lies in the flex side of your parser: It is never returning a CHAR token.

You haven't shown us the flex side of your parser, but how are you making flex distinguish between a SYMBOL_NAME and a CHAR? Typically the code that detects a <single_quote> <char> <single_quote> sequence is implemented in flex, not bison. The <char> is stored in the union and the return value CHAR. On the bison side, change your '\'' CHAR '\'' pattern to CHAR.

Alternatively, just change your '\'' CHAR '\'' pattern to '\'' SYMBOL_NAME '\''.