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1 /*
2  * Copyright 1999-2004 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 /*
17  * $Id: And.java,v 1.9 2004/02/17 04:35:12 minchau Exp $
18  */
19 package org.apache.xpath.operations;
20
21 import org.apache.xpath.XPathContext;
22 import org.apache.xpath.objects.XBoolean;
23 import org.apache.xpath.objects.XObject;
24
25 /**
26  * The 'and' operation expression executer.
27  */
28 public class And extends Operation
29 {
30
31   /**
32    * AND two expressions and return the boolean result. Override
33    * superclass method for optimization purposes.
34    *
35    * @param xctxt The runtime execution context.
36    *
37    * @return {@link org.apache.xpath.objects.XBoolean#S_TRUE} or
38    * {@link org.apache.xpath.objects.XBoolean#S_FALSE}.
39    *
40    * @throws javax.xml.transform.TransformerException
41    */
42   public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException JavaDoc
43   {
44
45     XObject expr1 = m_left.execute(xctxt);
46
47     if (expr1.bool())
48     {
49       XObject expr2 = m_right.execute(xctxt);
50
51       return expr2.bool() ? XBoolean.S_TRUE : XBoolean.S_FALSE;
52     }
53     else
54       return XBoolean.S_FALSE;
55   }
56   
57   /**
58    * Evaluate this operation directly to a boolean.
59    *
60    * @param xctxt The runtime execution context.
61    *
62    * @return The result of the operation as a boolean.
63    *
64    * @throws javax.xml.transform.TransformerException
65    */
66   public boolean bool(XPathContext xctxt)
67           throws javax.xml.transform.TransformerException JavaDoc
68   {
69     return (m_left.bool(xctxt) && m_right.bool(xctxt));
70   }
71
72 }
73
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