code: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements. See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership. The ASF licenses this file
   * to you 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.
   */
  /*
   * $Id$
   */
  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);
  
    /**
     * Get start to END should 'close' the iterator,
     * i.e. subsequent call to next() should return END.
     *
     * @return The root node of the iteration.
     */
    public int getStartNode();
  
    /**
     * @return true if this iterator has a reversed axis, else false.
     */
    public boolean isReverse();
  
    /**
     * @return a deep copy of this iterator. The clone should not be reset 
     * from its current position.
     */
    public DTMAxisIterator cloneIterator();
    
    /**
     * Set if restartable.
     */
    public void setRestartable(boolean isRestartable);
  
    /**
     * Return the node at the given position.
     * 
     * @param position The position
     * @return The node at the given position.
     */
    public int getNodeByPosition(int position);
  }
  