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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_AtomicComparators_H

#define Patternist_AtomicComparators_H

#include "qabstractfloat_p.h"

#include "qatomiccomparator_p.h"

#include "qprimitives_p.h"

/**

 * @file

 * @short Contains all the classes implementing comparisons between atomic values.

 */

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Performs case @em sensitive string comparison

     * between @c xs:anyUri, @c xs:string, and @c xs:untypedAtomic.

     *

     * @ingroup Patternist_xdm

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

     */

    class StringComparator : public AtomicComparator

    {

    public:

        /**

         * Compares two strings, and returns the appropriate AtomicComparator::ComparisonResult enum. This

         * is a bit simplified version of string comparison as defined in the XPath specifications,

         * since this does not take any string collations into account(which an implementation neither

         * is required to do).

         *

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

         * 2.0 Functions and Operators, 7.3 ValueComparison::Equality and Comparison of Strings</a>

         */

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        /**

         * Compares two strings, and returns @c true if they are considered equal as per

         * an ordinary string comparison. In other words, this is an implementation with

         * the Unicode code point collation.

         *

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

         * 2.0 Functions and Operators, 7.3 ValueComparison::Equality and Comparison of Strings</a>

         */

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Performs case @em insensitive string comparison

     * between @c xs:anyUri, @c xs:string, and @c xs:untypedAtomic.

     *

     * @ingroup Patternist_xdm

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

     */

    class CaseInsensitiveStringComparator : public AtomicComparator

    {

    public:

        /**

         * Converts both string values to upper case and afterwards compare them.

         */

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        /**

         * Converts both string values case insensitively.

         */

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares @c xs:base64Binary and @c xs:hexBinary values.

     *

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

     */

    class BinaryDataComparator : public AtomicComparator

    {

    public:

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares @c xs:boolean values.

     *

     * This is done via the object's Boolean::evaluteEBV() function.

     *

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

     */

    class BooleanComparator : public AtomicComparator

    {

    public:

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares @c xs:double values.

     *

     * @todo Add docs about numeric promotion

     *

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

     */

    class AbstractFloatComparator : public AtomicComparator

    {

    public:

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares @c xs:double values for the purpose of sorting.

     *

     * @todo Add docs about numeric promotion

     *

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

     */

    template<const AtomicComparator::Operator t_op>

    class AbstractFloatSortComparator : public AbstractFloatComparator

    {

    public:

        virtual ComparisonResult compare(const Item &o1,

                                         const AtomicComparator::Operator op,

                                         const Item &o2) const

        {

            Q_ASSERT_X(t_op == OperatorLessThanNaNLeast || t_op == OperatorLessThanNaNGreatest, Q_FUNC_INFO,

                       "Can only be instantiated with those two.");

            Q_ASSERT(op == t_op);

            Q_UNUSED(op); /* Needed when building in release mode. */

            const xsDouble v1 = o1.template as<Numeric>()->toDouble();

            const xsDouble v2 = o2.template as<Numeric>()->toDouble();

            if(qIsNaN(v1) && !qIsNaN(v2))

                return t_op == OperatorLessThanNaNLeast ? LessThan : GreaterThan;

            if(!qIsNaN(v1) && qIsNaN(v2))

                return t_op == OperatorLessThanNaNLeast ? GreaterThan : LessThan;

            if(Double::isEqual(v1, v2))

                return Equal;

            else if(v1 < v2)

                return LessThan;

            else

                return GreaterThan;

        }

    };

    /**

     * @short Compares @c xs:decimal values.

     *

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

     */

    class DecimalComparator : public AtomicComparator

    {

    public:

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares @c xs:integer values.

     *

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

     */

    class IntegerComparator : public AtomicComparator

    {

    public:

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares @c xs:QName values.

     *

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

     */

    class QNameComparator : public AtomicComparator

    {

    public:

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares sub-classes of AbstractDateTime.

     *

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

     */

    class AbstractDateTimeComparator : public AtomicComparator

    {

    public:

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    };

    /**

     * @short Compares sub-classes of AbstractDuration.

     *

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

     */

    class AbstractDurationComparator : public AtomicComparator

    {

    public:

        virtual ComparisonResult compare(const Item &op1,

                                         const AtomicComparator::Operator op,

                                         const Item &op2) const;

        virtual bool equals(const Item &op1,

                            const Item &op2) const;

    private:

        static inline QDateTime addDurationToDateTime(const QDateTime &dateTime,

                                                      const AbstractDuration *const duration);

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif