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 * 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
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 * distributed under the License is distributed on an "AS IS" BASIS,
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package com.sun.org.apache.xalan.internal.xsltc.dom;

import com.sun.org.apache.xalan.internal.xsltc.runtime.BasisLibrary;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.dtm.ref.DTMAxisIteratorBase;

This is a special kind of iterator that takes a source iterator and a
node N. If initialized with a node M (the parent of N) it computes the
position of N amongst the children of M. This position can be obtained
by calling getPosition().
It is an iterator even though next() will never be called. It is used to
match patterns with a single predicate like:
   BOOK[position() = last()]
In this example, the source iterator will return elements of type BOOK,
a call to position() will return the position of N. Notice that because
of the way the pattern matching is implemented, N will always be a node
in the source since (i) it is a BOOK or the test sequence would not be
considered and (ii) the source iterator is initialized with M which is
the parent of N. Also, and still in this example, a call to last() will
return the number of elements in the source (i.e. the number of BOOKs).
Author:
Jacek Ambroziak, Santiago Pericas-Geertsen/**
 * This is a special kind of iterator that takes a source iterator and a
 * node N. If initialized with a node M (the parent of N) it computes the
 * position of N amongst the children of M. This position can be obtained
 * by calling getPosition().
 * It is an iterator even though next() will never be called. It is used to
 * match patterns with a single predicate like:
 *
 *    BOOK[position() = last()]
 *
 * In this example, the source iterator will return elements of type BOOK,
 * a call to position() will return the position of N. Notice that because
 * of the way the pattern matching is implemented, N will always be a node
 * in the source since (i) it is a BOOK or the test sequence would not be
 * considered and (ii) the source iterator is initialized with M which is
 * the parent of N. Also, and still in this example, a call to last() will
 * return the number of elements in the source (i.e. the number of BOOKs).
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 */
public final class MatchingIterator extends DTMAxisIteratorBase {

    
A reference to a source iterator.
/**
     * A reference to a source iterator.
     */
    private DTMAxisIterator _source;

    
The node to match.
/**
     * The node to match.
     */
    private final int _match;

    public MatchingIterator(int match, DTMAxisIterator source) {
        _source = source;
        _match = match;
    }


    public void setRestartable(boolean isRestartable) {
        _isRestartable = isRestartable;
        _source.setRestartable(isRestartable);
    }

    public DTMAxisIterator cloneIterator() {

        try {
            final MatchingIterator clone = (MatchingIterator) super.clone();
            clone._source = _source.cloneIterator();
            clone._isRestartable = false;
            return clone.reset();
        }
        catch (CloneNotSupportedException e) {
            BasisLibrary.runTimeError(BasisLibrary.ITERATOR_CLONE_ERR,
                                      e.toString());
            return null;
        }
    }

    public DTMAxisIterator setStartNode(int node) {
        if (_isRestartable) {
            // iterator is not a clone
            _source.setStartNode(node);

            // Calculate the position of the node in the set
            _position = 1;
            while ((node = _source.next()) != END && node != _match) {
                _position++;
            }
        }
        return this;
    }

    public DTMAxisIterator reset() {
        _source.reset();
        return resetPosition();
    }

    public int next() {
        return _source.next();
    }

    public int getLast() {
        if (_last == -1) {
            _last = _source.getLast();
        }
        return _last;
    }

    public int getPosition() {
        return _position;
    }

    public void setMark() {
        _source.setMark();
    }

    public void gotoMark() {
        _source.gotoMark();
    }
}