leafnode.java

jakarta-oro-2.0.8 正则表达式 引擎 源代码

/*
 * $Id: LeafNode.java,v 1.7 2003/11/07 20:16:24 dfs Exp $
 *
 * ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation", "Jakarta-Oro" 
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache" 
 *    or "Jakarta-Oro", nor may "Apache" or "Jakarta-Oro" appear in their 
 *    name, without prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */


package org.apache.oro.text.awk;

import java.util.*;

/**
 * @version @version@
 * @since 1.0
 */
abstract class LeafNode extends SyntaxNode {
  static final int _NUM_TOKENS                    = 256;
  static final int _END_MARKER_TOKEN              = _NUM_TOKENS;

  protected int _position;
  protected BitSet _positionSet;

  LeafNode(int position){
    _position = position;
    _positionSet = new BitSet(position + 1);
    _positionSet.set(position);
  }

  abstract boolean _matches(char token);
  final boolean _nullable()     { return false; }
  final BitSet _firstPosition() { return _positionSet; }
  final BitSet _lastPosition()  { return _positionSet; }
  final void _followPosition(BitSet[] follow, SyntaxNode[] nodes) {
    nodes[_position] = this;
  }
}