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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  }