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 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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.

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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

 * @author Santiago Pericas-Geertsen

 */

public final class MatchingIterator extends DTMAxisIteratorBase {

    /**

     * A reference to a source iterator.

     */

    private DTMAxisIterator _source;

    /**

     * 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();

    }

}