1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements. See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership. The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the  "License");
7  * you may not use this file except in compliance with the License.
8  * You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing, software
13  * distributed under the License is distributed on an "AS IS" BASIS,
14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15  * See the License for the specific language governing permissions and
16  * limitations under the License.
17  */
18 /*
19  * $Id: Minus.java 468655 2006-10-28 07:12:06Z minchau $
20  */
21 package org.apache.xpath.operations;
22 
23 import org.apache.xpath.XPathContext;
24 import org.apache.xpath.objects.XNumber;
25 import org.apache.xpath.objects.XObject;
26 
27 /**
28  * The binary '-' operation expression executer.
29  */
30 public class Minus extends Operation
31 {
32     static final long serialVersionUID = -5297672838170871043L;
33 
34   /**
35    * Apply the operation to two operands, and return the result.
36    *
37    *
38    * @param left non-null reference to the evaluated left operand.
39    * @param right non-null reference to the evaluated right operand.
40    *
41    * @return non-null reference to the XObject that represents the
42    *         result of the operation.
43    *
44    * @throws javax.xml.transform.TransformerException
45    */
operate(XObject left, XObject right)46   public XObject operate(XObject left, XObject right)
47           throws javax.xml.transform.TransformerException
48   {
49     return new XNumber(left.num() - right.num());
50   }
51 
52   /**
53    * Evaluate this operation directly to a double.
54    *
55    * @param xctxt The runtime execution context.
56    *
57    * @return The result of the operation as a double.
58    *
59    * @throws javax.xml.transform.TransformerException
60    */
num(XPathContext xctxt)61   public double num(XPathContext xctxt)
62           throws javax.xml.transform.TransformerException
63   {
64 
65     return (m_left.num(xctxt) - m_right.num(xctxt));
66   }
67 
68 }
69