1 // JavaCup specification for a simple expression evaluator (w/ actions)
3 package java_cup.simple_calc;
5 import java_cup.runtime.*;
7 /* Terminals (tokens returned by the scanner). */
8 terminal SEMI, PLUS, MINUS, TIMES, DIVIDE, MOD;
9 terminal UMINUS, LPAREN, RPAREN;
10 terminal Integer NUMBER;
13 non terminal Object expr_list, expr_part;
14 non terminal Integer expr;
17 precedence left PLUS, MINUS;
18 precedence left TIMES, DIVIDE, MOD;
19 precedence left UMINUS, LPAREN;
22 expr_list ::= expr_list expr_part
27 {: System.out.println("= " + e); :}
31 expr ::= expr:e1 PLUS expr:e2
32 {: RESULT = new Integer(e1.intValue() + e2.intValue()); :}
35 {: RESULT = new Integer(e1.intValue() - e2.intValue()); :}
38 {: RESULT = new Integer(e1.intValue() * e2.intValue()); :}
40 expr:e1 DIVIDE expr:e2
41 {: RESULT = new Integer(e1.intValue() / e2.intValue()); :}
44 {: RESULT = new Integer(e1.intValue() % e2.intValue()); :}
50 {: RESULT = new Integer(0 - e.intValue()); :}