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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_CardinalityVerifier_H

#define Patternist_CardinalityVerifier_H

#include "qsinglecontainer_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Verifies that the sequence an Expression evaluates to conforms to a Cardinality.

     *

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

     * XPath 2.0 Functions and Operators, 15.2 Functions That Test the Cardinality of Sequences</a>

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

     * @ingroup Patternist_expressions

     */

    class CardinalityVerifier : public SingleContainer

    {

    public:

        CardinalityVerifier(const Expression::Ptr &operand,

                            const Cardinality &card,

                            const ReportContext::ErrorCode code);

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

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

        virtual SequenceType::List expectedOperandTypes() const;

        virtual SequenceType::Ptr staticType() const;

        virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;

        /**

         * If the static cardinality of the operand is within the required cardinality,

         * the operand is returned as is, since results will always be valid and hence

         * is not a CardinalityVerifier necessary.

         */

        virtual Expression::Ptr compress(const StaticContext::Ptr &context);

        /**

         * A utility function for determining whether the static type of an Expression matches

         * a cardinality. More specifically, this function performs the cardinality verification

         * part of the Function Conversion Rules.

         *

         * @todo Mention the rewrite and when exactly an error is issued via @p context

         */

        static Expression::Ptr

        verifyCardinality(const Expression::Ptr &operand,

                          const Cardinality &card,

                          const StaticContext::Ptr &context,

                          const ReportContext::ErrorCode code = ReportContext::XPTY0004);

        virtual const SourceLocationReflection *actualReflection() const;

        ID id() const;

    private:

        /**

         * Centralizes a message string in order to increase consistency and

         * reduce work for translators.

         */

        static inline QString wrongCardinality(const Cardinality &req,

                                               const Cardinality &got = Cardinality::empty());

        const Cardinality m_reqCard;

        const bool m_allowsMany;

        const ReportContext::ErrorCode m_errorCode;

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif