/*
 * This file is part of %PACKAGENAME%.
 *
 * %PACKAGENAME% is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * %PACKAGENAME% is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with %PACKAGENAME%. If not, see <http://www.gnu.org/licenses/>.
 *
 * For more information please see <http://www.%PACKAGENAME%.org>
 * or contact Peter Baumann via <baumann@rasdaman.com>.
 *
 * Copyright 2009 Jacobs University Bremen, Peter Baumann.
 */

// JavaCup specification for a simple expression evaluator (w/ actions)

package java_cup.simple_calc;

import java_cup.runtime.*;

/* Terminals (tokens returned by the scanner). */
terminal           SEMI, PLUS, MINUS, TIMES, DIVIDE, MOD;
terminal           UMINUS, LPAREN, RPAREN;
terminal Integer   NUMBER;

/* Non terminals */
non terminal Object     expr_list, expr_part;
non terminal Integer    expr;

/* Precedences */
precedence left PLUS, MINUS;
precedence left TIMES, DIVIDE, MOD;
precedence left UMINUS, LPAREN;

/* The grammar */
expr_list ::= expr_list expr_part 
	      | 
              expr_part;

expr_part ::= expr:e 
	      {: System.out.println("= " + e); :} 
              SEMI              
	      ;

expr      ::= expr:e1 PLUS expr:e2    
	      {: RESULT = new Integer(e1.intValue() + e2.intValue()); :} 
	      | 
              expr:e1 MINUS expr:e2    
              {: RESULT = new Integer(e1.intValue() - e2.intValue()); :} 
	      | 
              expr:e1 TIMES expr:e2 
	      {: RESULT = new Integer(e1.intValue() * e2.intValue()); :} 
	      | 
              expr:e1 DIVIDE expr:e2 
	      {: RESULT = new Integer(e1.intValue() / e2.intValue()); :} 
	      | 
              expr:e1 MOD expr:e2 
	      {: RESULT = new Integer(e1.intValue() % e2.intValue()); :} 
	      | 
              NUMBER:n                 
	      {: RESULT = n; :} 
	      | 
              MINUS expr:e             
	      {: RESULT = new Integer(0 - e.intValue()); :} 
	      %prec UMINUS
	      | 
              LPAREN expr:e RPAREN     
	      {: RESULT = e; :} 
	      ;