/****************************************************************************
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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_IntersectIterator_H
#define Patternist_IntersectIterator_H

#include "qitem_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{
    /**
     * @short Implements the @c intersect operator. That is, the computation
     * of the intersection between two sequences of nodes.
     *
     * The @c intersect operator can be seen as logical @c AND of the two sets.
     *
     * @ingroup Patternist_iterators
     */
    class IntersectIterator : public Item::Iterator
    {
    public:
        /**
         * It is assumed that @p it1 and @p it2 are in document order and
         * without duplicates.
         */
        IntersectIterator(const Item::Iterator::Ptr &it1,
                          const Item::Iterator::Ptr &it2);

        virtual Item next();
        virtual Item current() const;
        virtual xsInteger position() const;
        virtual Item::Iterator::Ptr copy() const;

    private:
        inline Item closedExit()
        {
            m_position = -1;
            m_current = Item();
            return Item();
        }

        const Item::Iterator::Ptr   m_it1;
        const Item::Iterator::Ptr   m_it2;
        Item                        m_current;
        xsInteger                   m_position;
        Item                        m_node1;
        Item                        m_node2;
    };
}

QT_END_NAMESPACE

QT_END_HEADER

#endif
