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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.trigger;
22  
23  
24  import antlr.TokenStream;
25  
26  
27  /**
28   * A reusable lexer class extended from antlr generated parser for an LDAP
29   * Trigger Specification as defined at <a
30   * href="http://docs.safehaus.org/display/APACHEDS/Grammar+for+Triggers">
31   * The ABNF grammar for LDAP Triggers</a>.
32   * 
33   * <p>This class enables the reuse of the antlr lexer without having to recreate
34   * the it every time as stated in <a
35   * href="http://www.antlr.org:8080/pipermail/antlr-interest/2003-April/003631.html">
36   * an ANTLR Interest Group mail</a> .
37   * 
38   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
39   */
40  class ReusableAntlrTriggerSpecificationParser extends AntlrTriggerSpecificationParser
41  {
42      /**
43       * Creates a ReusableAntlrTriggerSpecificationParser instance.
44       */
45      ReusableAntlrTriggerSpecificationParser( TokenStream lexer )
46      {
47          super( lexer );
48      }
49  
50  
51      /**
52       * Resets the state of an antlr parser.
53       */
54      public void resetState()
55      {
56          // no set method for this protected field.
57          this.traceDepth = 0;
58  
59          this.getInputState().reset();
60      }
61  }