xpression evaluator (no actions)

import java_cup.runtime.*;

/* Preliminaries to set up and use the scanner.  */
init with {: scanner.init();              :};
scan with {: return scanner.next_token(); :};

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

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

/* Precedenc