+++ /dev/null
-// 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; :}
- ;