Parser


Yet another example:
   | for '(' expr_opt   ';' expr_opt ';' expr_opt ')'  statement 
     {
         $$ = createFor ($1, $3 , $5 , $7, $9 );
     }
where
ast *createFor (op, ast *init_expr, ast *cond_expr,
                ast *terminate_expr, ast *for_body);