/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 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 "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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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 and was
 * originally based on software copyright (c) 2001, Sun
 * Microsystems., http://www.sun.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xml.dtm;

/**
 * This class iterates over a single XPath Axis, and returns node handles.
 */
public interface DTMAxisIterator extends Cloneable
{

  /** Specifies the end of the iteration, and is the same as DTM.NULL.  */
  public static final int END = DTM.NULL;

  /**
   * Get the next node in the iteration.
   *
   * @return The next node handle in the iteration, or END.
   */
  public int next();

  /**
   * Resets the iterator to the last start node.
   *
   * @return A DTMAxisIterator, which may or may not be the same as this 
   *         iterator.
   */
  public DTMAxisIterator reset();

  /**
   * @return the number of nodes in this iterator.  This may be an expensive 
   * operation when called the first time.
   */
  public int getLast();

  /**
   * @return The position of the current node in the set, as defined by XPath.
   */
  public int getPosition();

  /**
   * Remembers the current node for the next call to gotoMark().
   */
  public void setMark();

  /**
   * Restores the current node remembered by setMark().
   */
  public void gotoMark();

  /**
   * Set start to END should 'close' the iterator,
   * i.e. subsequent call to next() should return END.
   *
   * @param node Sets the root of the iteration.
   *
   * @return A DTMAxisIterator set to the start of the iteration.
   */
  public DTMAxisIterator setStartNode(int node);

  /**
   * @return true if this iterator has a reversed axis, else false.
   */
  public boolean isReverse();

  /**
   * @return a deep copy of this iterator. The clone and/or the original
   * may become non-restartable as a side effect of this operation.
   */
  public DTMAxisIterator cloneIterator();
}