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//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

#ifndef Patternist_RemovalIterator_H

#define Patternist_RemovalIterator_H

#include "qitem_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Removes one items at a specified position from an input QAbstractXmlForwardIterator.

     *

     * RemoveIterator removes an item from a sequence at a certain position,

     * while retaining the pull-based characteristic of being an QAbstractXmlForwardIterator itself. The

     * RemovalIterator's constructor is passed an QAbstractXmlForwardIterator, the QAbstractXmlForwardIterator to

     * remove from, and the position of the item to remove. When calling the RemovalIterator's

     * functions, it acts as an ordinary QAbstractXmlForwardIterator, taking into account that

     * one item is removed from the source QAbstractXmlForwardIterator.

     *

     * The RemovalIterator class contains the central business logic for implementing the

     * <tt>fn:remove()</tt> function, whose definition therefore specifies the detailed behaviors

     * of RemovalIterator.

     *

     * @see <a href="http://www.w3.org/TR/xpath-functions/#func-remove">XQuery 1.0

     * and XPath 2.0 Functions and Operators, 15.1.8 fn:remove</a>

     * @author Frans Englich <frans.englich@nokia.com>

     * @ingroup Patternist_iterators

     */

    class RemovalIterator : public Item::Iterator

    {

    public:

        /**

         * Creates an RemovalIterator.

         *

         * @param target the QAbstractXmlForwardIterator containing the sequence of items

         * which the item at position @p position should be removed from.

         * @param position the position of the item to remove. Must be

         * 1 or larger.

         */

        RemovalIterator(const Item::Iterator::Ptr &target,

                        const xsInteger position);

        virtual Item next();

        virtual Item current() const;

        virtual xsInteger position() const;

        /**

         * The QAbstractXmlForwardIterator's count is computed by subtracting one from the source

         * QAbstractXmlForwardIterator's count.

         */

        virtual xsInteger count();

        virtual Item::Iterator::Ptr copy() const;

    private:

        const Item::Iterator::Ptr m_target;

        const xsInteger m_removalPos;

        Item m_current;

        xsInteger m_position;

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif