001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *  
010     *    http://www.apache.org/licenses/LICENSE-2.0
011     *  
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License. 
018     *  
019     */
020    package org.apache.directory.shared.ldap.schema.parsers;
021    
022    import org.apache.directory.shared.ldap.schema.syntax.AntlrSchemaParser;
023    
024    import antlr.TokenStream;
025    
026    /**
027     * A reusable parser class extended from antlr generated parser for an LDAP
028     * schema as defined in RFC 4512. This class
029     * enables the reuse of the antlr parser without having to recreate the it every
030     * time as stated in <a
031     * href="http://www.antlr.org:8080/pipermail/antlr-interest/2003-April/003631.html">
032     * a Antlr Interest Group mail</a> .
033     * 
034     * @see <a href="http://www.faqs.org/rfcs/rfc3672.html">RFC 3672</a>
035     * @version $Rev$, $Date$
036     */
037    public class ReusableAntlrSchemaParser extends AntlrSchemaParser
038    {
039        /**
040         * Creates a ReusableAntlrSchemaParser instance.
041         */
042        public ReusableAntlrSchemaParser( TokenStream lexer )
043        {
044            super( lexer );
045        }
046    
047    
048        /**
049         * Resets the state of an antlr parser.
050         */
051        public void resetState()
052        {
053            // no set method for this protected field.
054            this.traceDepth = 0;
055    
056            this.getInputState().reset();
057        }
058    }