1public
2class UnaryMinus extends UnaryExpr {
3
4
5
6 public
7 UnaryMinus(Expr operand) {
8 super(operand);
9 }
10
11
12
13
14
15
16 protected
17 Object op1(Object v1) {
18
19
20
21 if ( v1 instanceof Integer ) {
22 return
23 new Integer(- ((Integer)v1).intValue());
24 }
25
26
27
28 if ( v1 instanceof Double ) {
29 return
30 new Double(- ((Double)v1).doubleValue());
31 }
32
33
34
35 throw
36 new IllegalArgumentException("unary - : illegal operand type");
37 }
38
39
40
41 public
42 String op1ToString() {
43 return
44 "-";
45 }
46}
47
48
49
