/****************************************************************************
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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_Atomizer_H
#define Patternist_Atomizer_H

#include "qitem_p.h"
#include "qsinglecontainer_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{

    /**
     * @short Performs atomization. Effectively, it is an implementation
     * of the <tt>fn:data()</tt> function.
     *
     * @see <a href="http://www.w3.org/TR/xpath-functions/#func-data">XQuery 1.0 and XPath
     * 2.0 Functions and Operators, 2.4 fn:data</a>
     * @see <a href="http://www.w3.org/TR/xpath20/#id-atomization">XML
     * Path Language (XPath) 2.0, 2.4.2 Atomization</a>
     * @author Frans Englich <fenglich@trolltech.com>
     * @ingroup Patternist_expressions
     */
    class Atomizer : public SingleContainer
    {
    public:
        Atomizer(const Expression::Ptr &operand);

        virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
        virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &) const;

        virtual SequenceType::Ptr staticType() const;

        virtual SequenceType::List expectedOperandTypes() const;
        virtual const SourceLocationReflection *actualReflection() const;

        /**
         * Makes an early compression, by returning the result of
         * the type checked operand, if the operand has the static type
         * xs:anyAtomicType(no atomization needed).
         */
        virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
                                          const SequenceType::Ptr &reqType);

        inline Item::Iterator::Ptr mapToSequence(const Item &item,
                                                 const DynamicContext::Ptr &context) const;
        virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;

    private:
        typedef QExplicitlySharedDataPointer<const Atomizer> ConstPtr;
    };
}

QT_END_NAMESPACE

QT_END_HEADER

#endif