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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
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  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,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  
21  package org.apache.directory.api.ldap.model.subtree;
22  
23  
24  import org.apache.directory.api.ldap.model.subtree.AntlrSubtreeSpecificationParser;
25  
26  import antlr.TokenStream;
27  
28  
29  /**
30   * A reusable parser class extended from antlr generated parser for an LDAP
31   * subtree specification as defined by <a
32   * href="http://www.faqs.org/rfcs/rfc3672.html"> RFC 3672</a>. This class
33   * enables the reuse of the antlr parser without having to recreate the it every
34   * time as stated in <a
35   * href="http://www.antlr.org:8080/pipermail/antlr-interest/2003-April/003631.html">
36   * a Antlr Interest Group mail</a> .
37   * 
38   * @see <a href="http://www.faqs.org/rfcs/rfc3672.html">RFC 3672</a>
39   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
40   */
41  class ReusableAntlrSubtreeSpecificationParser extends AntlrSubtreeSpecificationParser
42  {
43      /**
44       * Creates a ReusableAntlrSubtreeSpecificationParser instance.
45       */
46      public ReusableAntlrSubtreeSpecificationParser( TokenStream lexer )
47      {
48          super( lexer );
49      }
50  
51  
52      /**
53       * Resets the state of an antlr parser.
54       */
55      public void resetState()
56      {
57          // no set method for this protected field.
58          this.traceDepth = 0;
59  
60          this.getInputState().reset();
61      }
62  }