1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.jxpath.ri.compiler;
18
19 import org.apache.commons.jxpath.ri.EvalContext;
20 import org.apache.commons.jxpath.ri.InfoSetUtil;
21
22 /**
23 * Implementation of {@link Expression} for the operation "-".
24 *
25 * @author Dmitri Plotnikov
26 * @version $Revision: 652845 $ $Date: 2008-05-02 19:46:46 +0200 (Fr, 02 Mai 2008) $
27 */
28 public class CoreOperationSubtract extends CoreOperation {
29
30 /**
31 * Create a new CoreOperationSubtract.
32 * @param arg1 minuend
33 * @param arg2 subtrahend
34 */
35 public CoreOperationSubtract(Expression arg1, Expression arg2) {
36 super(new Expression[] { arg1, arg2 });
37 }
38
39 public Object computeValue(EvalContext context) {
40 double l = InfoSetUtil.doubleValue(args[0].computeValue(context));
41 double r = InfoSetUtil.doubleValue(args[1].computeValue(context));
42 return new Double(l - r);
43 }
44
45 protected int getPrecedence() {
46 return ADD_PRECEDENCE;
47 }
48
49 protected boolean isSymmetric() {
50 return false;
51 }
52
53 public String getSymbol() {
54 return "-";
55 }
56 }