KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > apache > commons > jxpath > ri > compiler > CoreOperationSubtract


1 /*
2  * Copyright 2002-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.apache.commons.jxpath.ri.compiler;
17
18 import org.apache.commons.jxpath.ri.EvalContext;
19 import org.apache.commons.jxpath.ri.InfoSetUtil;
20
21 /**
22  * Implementation of Expression for the operation "-".
23  *
24  * @author Dmitri Plotnikov
25  * @version $Revision: 1.3 $ $Date: 2004/02/29 14:17:39 $
26  */
27 public class CoreOperationSubtract extends CoreOperation {
28
29     public CoreOperationSubtract(Expression arg1, Expression arg2) {
30         super(new Expression[] { arg1, arg2 });
31     }
32
33     public Object JavaDoc computeValue(EvalContext context) {
34         double l = InfoSetUtil.doubleValue(args[0].computeValue(context));
35         double r = InfoSetUtil.doubleValue(args[1].computeValue(context));
36         return new Double JavaDoc(l - r);
37     }
38     
39     protected int getPrecedence() {
40         return 4;
41     }
42
43     protected boolean isSymmetric() {
44         return false;
45     }
46     
47     public String JavaDoc getSymbol() {
48         return "-";
49     }
50 }
51
Popular Tags