/* Mini Calculator */
/* calc.y */


%{
#include <stdlib.h>
#include <string.h>
#include "heading.h"

int yyerror(char *s);
int yylex(void);

%}

%union{
  int		int_val;
  char*		str_val;
  int		int_list[4];
}

%start	input 

%token	<int_val>	INTEGER_LITERAL
%token  <int_val>   MNEMONIC
%token  <str_val> 	SYMBOL

%type 	<int_val>	operand
%type 	<int_list>	opseq


%%

input:	/* empty */
		| codebl { printf("input-codebl\n") }
		;

codebl: statem 	{ printf("codebl--statem\n") }
        | codebl '\n' statem 
        ;

statem:	instruction { printf("statem-instruction\n"); }
		;
		
instruction: SYMBOL opseq { printf("instruction-SYMBOL-opseq\n"); }
		;
		
opseq:   /* empty */ { printf("opseq-empty\n"); }
        | opseq1 { printf("opseq-opseq1\n"); }
        ;

opseq1:  operand { printf("opseq1-operand\n"); }
        | opseq ',' operand { printf("opseq1-wcomma\n"); }
        ;

operand: MNEMONIC { $$ = $1; }
		| INTEGER_LITERAL { printf("int-lit\n"); }
		| offaddr { printf("operand-offaddr\n"); }
		;
		
offaddr: INTEGER_LITERAL '(' operand ')' { printf("offaddr\n"); }
		;

%%

int yyerror(char *s)
{
	extern int yylineno;
	extern char *yytext;
  
	fprintf(stderr, "error: %s at symbol %s on line %d.\n", s, yytext,yylineno);
	exit(1);

}