/*
 * ====================================================================
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 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999-2003 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:
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
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 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
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 * ====================================================================
 *
 * 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/>.
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 */
package org.apache.wicket.util.diff.myers;

/**
 * <p>
 * Title:
 * </p>
 * <p>
 * Description:
 * </p>
 * <p>
 * Copyright: Copyright (c) 2002
 * </p>
 * <p>
 * Company:
 * </p>
 * 
 * @author not attributable
 * @version 1.0
 */

/**
 * A diffnode in a diffpath.
 * <p>
 * A DiffNode and its previous node mark a delta between two input sequences, that is, two differing
 * subsequences between (possibly zero length) matching sequences.
 * 
 * {@link DiffNode DiffNodes} and {@link Snake Snakes} allow for compression of diffpaths, as each
 * snake is represented by a single {@link Snake Snake} node and each contiguous series of
 * insertions and deletions is represented by a single {@link DiffNode DiffNodes}.
 * 
 * @version $Revision: 1.1 $ $Date: 2006/03/12 00:24:21 $
 * @author <a href="mailto:juanco@suigeneris.org">Juanco Anez</a>
 * 
 */
public final class DiffNode extends PathNode
{
	/**
	 * Constructs a DiffNode.
	 * <p>
	 * DiffNodes are compressed. That means that the path pointed to by the <code>prev</code>
	 * parameter will be followed using {@link PathNode#previousSnake} until a non-diff node is
	 * found.
	 * 
	 * @param i
	 *            the position in the original sequence
	 * @param j
	 *            the position in the revised sequence
	 * @param prev
	 *            the previous node in the path.
	 */
	public DiffNode(final int i, final int j, final PathNode prev)
	{
		super(i, j, (prev == null ? null : prev.previousSnake()));
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @return false, always
	 */
	@Override
	public boolean isSnake()
	{
		return false;
	}

}