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: Neg.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 unary '-' operation expression executer.
29  */
30 public class Neg extends UnaryOperation
31 {
32     static final long serialVersionUID = -6280607702375702291L;
33 
34   /**
35    * Apply the operation to two operands, and return the result.
36    *
37    *
38    * @param right non-null reference to the evaluated right operand.
39    *
40    * @return non-null reference to the XObject that represents the result of the operation.
41    *
42    * @throws javax.xml.transform.TransformerException
43    */
operate(XObject right)44   public XObject operate(XObject right) throws javax.xml.transform.TransformerException
45   {
46     return new XNumber(-right.num());
47   }
48 
49   /**
50    * Evaluate this operation directly to a double.
51    *
52    * @param xctxt The runtime execution context.
53    *
54    * @return The result of the operation as a double.
55    *
56    * @throws javax.xml.transform.TransformerException
57    */
num(XPathContext xctxt)58   public double num(XPathContext xctxt)
59           throws javax.xml.transform.TransformerException
60   {
61 
62     return -(m_right.num(xctxt));
63   }
64 
65 }
66