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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.jexl.parser;
17  
18  import org.apache.commons.jexl.JexlContext;
19  import org.apache.commons.jexl.util.Coercion;
20  
21  /***
22   *   Not :   'not' or '!'
23   *
24   *  @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
25   *  @version $Id: ASTNotNode.java,v 1.3 2004/02/28 13:45:20 yoavs Exp $
26   */
27  
28  public class ASTNotNode extends SimpleNode
29  {
30      public ASTNotNode(int id)
31      {
32      super(id);
33      }
34  
35      public ASTNotNode(Parser p, int id)
36      {
37          super(p, id);
38      }
39  
40  
41      /*** Accept the visitor. **/
42      public Object jjtAccept(ParserVisitor visitor, Object data)
43      {
44          return visitor.visit(this, data);
45      }
46  
47      public Object value(JexlContext jc)
48          throws Exception
49      {
50          Object val = ((SimpleNode) jjtGetChild(0)).value(jc);
51  
52          /*
53           * coercion rules
54           */
55  
56          Boolean b = Coercion.coerceBoolean(val);
57  
58          if (b != null)
59              return b.booleanValue() ? Boolean.FALSE : Boolean.TRUE;
60  
61          throw new Exception("expression not boolean valued");
62      }
63  
64  }