common/subtree/ReusableAntlrSubtreeSpecificationLexer.java

/*
 *   Copyright 2004 The Apache Software Foundation
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 *
 */


package org.apache.ldap.common.subtree;


import java.io.Reader;

import antlr.CharBuffer;
import antlr.LexerSharedInputState;


/**
 * A reusable lexer class extended from antlr generated lexer for an LDAP
 * subtree specification as defined by <a href="http://www.faqs.org/rfcs/rfc3672.html">
 * RFC 3672</a>.  This class enables the reuse of the antlr lexer without having to
 * recreate the it every time as stated in 
 * <a href="http://www.antlr.org:8080/pipermail/antlr-interest/2003-April/003631.html">
 * a Antlr Interest Group mail</a> .
 *
 * @see <a href="http://www.faqs.org/rfcs/rfc3672.html">RFC 3672</a>
 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
 * @version $Rev$
 */
public class ReusableAntlrSubtreeSpecificationLexer extends AntlrSubtreeSpecificationLexer
{
    private boolean savedCaseSensitive;
    private boolean savedCaseSensitiveLiterals;

    /**
     * Creates a ReusableAntlrSubtreeSpecificationLexer instance.
     *
     * @param in the input to the lexer
     */
    public ReusableAntlrSubtreeSpecificationLexer( Reader in )
    {
        super( in );
        savedCaseSensitive = getCaseSensitive();
        savedCaseSensitiveLiterals = getCaseSensitiveLiterals();
    }


    /**
     * Resets the state of an antlr lexer and initializes it with new input.
     *
     * @param in the input to the lexer
     */
    public void prepareNextInput( Reader in )
    {
        CharBuffer buf = new CharBuffer( in );
        LexerSharedInputState state = new LexerSharedInputState( buf );
        this.setInputState(state);
        
        this.setCaseSensitive(savedCaseSensitive);
        
        // no set method for this protected field.
        this.caseSensitiveLiterals = savedCaseSensitiveLiterals;
    }
}
1	/*
2	* Copyright 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	*/
17
18
19	package org.apache.ldap.common.subtree;
20
21
22	import java.io.Reader;
23
24	import antlr.CharBuffer;
25	import antlr.LexerSharedInputState;
26
27
28	/**
29	* A reusable lexer class extended from antlr generated lexer for an LDAP
30	* subtree specification as defined by <a href="http://www.faqs.org/rfcs/rfc3672.html">
31	* RFC 3672</a>. This class enables the reuse of the antlr lexer without having to
32	* recreate the it every time as stated in
33	* <a href="http://www.antlr.org:8080/pipermail/antlr-interest/2003-April/003631.html">
34	* a Antlr Interest Group mail</a> .
35	*
36	* @see <a href="http://www.faqs.org/rfcs/rfc3672.html">RFC 3672</a>
37	* @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
38	* @version $Rev$
39	*/
40	public class ReusableAntlrSubtreeSpecificationLexer extends AntlrSubtreeSpecificationLexer
41	{
42	private boolean savedCaseSensitive;
43	private boolean savedCaseSensitiveLiterals;
44
45	/**
46	* Creates a ReusableAntlrSubtreeSpecificationLexer instance.
47	*
48	* @param in the input to the lexer
49	*/
50	public ReusableAntlrSubtreeSpecificationLexer( Reader in )
51	{
52	super( in );
53	savedCaseSensitive = getCaseSensitive();
54	savedCaseSensitiveLiterals = getCaseSensitiveLiterals();
55	}
56
57
58	/**
59	* Resets the state of an antlr lexer and initializes it with new input.
60	*
61	* @param in the input to the lexer
62	*/
63	public void prepareNextInput( Reader in )
64	{
65	CharBuffer buf = new CharBuffer( in );
66	LexerSharedInputState state = new LexerSharedInputState( buf );
67	this.setInputState(state);
68
69	this.setCaseSensitive(savedCaseSensitive);
70
71	// no set method for this protected field.
72	this.caseSensitiveLiterals = savedCaseSensitiveLiterals;
73	}
74	}