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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_Numeric_H

#define Patternist_Numeric_H

#include "qitem_p.h"

#include "qprimitives_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

/**

 * @file

 * @short Contains class Numeric. This file was originally called qnumeric_p.h,

 * but various build systems cannot handle that that name happens to be

 * identical to another one, the one in QtCore.

 */

namespace QPatternist

{

    /**

     * @short Base class for all numeric values.

     *

     * @section creation Creating Instances

     *

     * @todo

     * - Depending on what type of val

     * - Numeric::createFromString

     * - Various classes has ::Zero(), ::PosINF(), ::NaN(), NegINF()

     * - Never use constructor, use createFromNative, or createFromString.

     *

     * @see <a href="http://www.w3.org/TR/xquery-operators/#numeric-functions">XQuery 1.0

     * and XPath 2.0 Functions and Operators, 6 Functions and Operators on Numerics</a>

     * @see <a href="http://www.w3.org/TR/xquery-operators/#func-overloading">XQuery 1.0

     * and XPath 2.0 Functions and Operators, 1.2 Function Overloading</a>

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

     * @ingroup Patternist_xdm

     * @todo discuss data hierarchy the non existatnt number data type

     */

    class Numeric : public AtomicValue

    {

    public:

        typedef QExplicitlySharedDataPointer<Numeric> Ptr;

        /**

         * Creates a Numeric sub-class that is appropriate for @p number.

         *

         * @note usages of e/E is not handled; Double::fromLexical should

         * be used in that case. There is no function similar to fromLexical that also

         * takes double values into account(because that distinction is done in the scanner).

         *

         * Currently used in the parser to create appropriate expressions.

         */

        static AtomicValue::Ptr fromLexical(const QString &number);

        /**

         * @returns the particular number's value as a native representation of

         * the type xs:double. This can be considered that the value is cast to

         * xs:double.

         */

        virtual xsDouble toDouble() const = 0;

        /**

         * @returns the particular number's value as a native representation of

         * the type xs:integer. This can be considered that the value is cast to

         * xs:integer.

         */

        virtual xsInteger toInteger() const = 0;

        /**

         * @returns the number as an unsigned integer. If the value is not

         * unsigned, the code asserts and behavior is undefined.

         */

        virtual qulonglong toUnsignedInteger() const = 0;

        /**

         * @returns the particular number's value as a native representation of

         * the type xs:float. This can be considered that the value is cast to

         * xs:float.

         */

        virtual xsFloat toFloat() const = 0;

        /**

         * @returns the particular number's value as a native representation of

         * the type xs:decimal. This can be considered that the value is cast to

         * xs:decimal.

         */

        virtual xsFloat toDecimal() const = 0;

        /**

         * Performs the algorithm specified for the function fn:round on this Numeric,

         * and whose result is returned.

         *

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

         * and XPath 2.0 Functions and Operators, 6.4.4 fn:round</a>

         */

        virtual Numeric::Ptr round() const = 0;

        /**

         * Performs rounding as defined for the fn:round-half-to-even  on this Numeric,

         * and whose result is returned.

         *

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

         * and XPath 2.0 Functions and Operators, 6.4.5 fn:round-half-to-even</a>

         */

        virtual Numeric::Ptr roundHalfToEven(const xsInteger scale) const = 0;

        /**

         * Performs the algorithm specified for the function fn:floor on this Numeric,

         * and whose result is returned.

         *

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

         * and XPath 2.0 Functions and Operators, 6.4.3 fn:floor</a>

         */

        virtual Numeric::Ptr floor() const = 0;

        /**

         * Performs the algorithm specified for the function fn:ceiling on this Numeric,

         * and whose result is returned.

         *

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

         * and XPath 2.0 Functions and Operators, 6.4.2 fn:ceiling</a>

         */

        virtual Numeric::Ptr ceiling() const = 0;

        /**

         * Performs the algorithm specified for the function fn:abs on this Numeric,

         * and whose result is returned.

         *

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

         * and XPath 2.0 Functions and Operators, 6.4.1 fn:abs</a>

         */

        virtual Numeric::Ptr abs() const = 0;

        /**

         * Determines whether this Numeric is not-a-number, @c NaN. For numeric types

         * that cannot represent @c NaN, this function should return @c false.

         *

         * @returns @c true if this Numeric is @c NaN

         */

        virtual bool isNaN() const = 0;

        /**

         * Determines whether this Numeric is an infinite number. Signedness

         * is irrelevant, -INF as well as INF is considered infinity.

         *

         * For numeric types that cannot represent infinity, such as xs:integer

         * , this function should return @c false.

         *

         * @returns @c true if this Numeric is an infinite number

         */

        virtual bool isInf() const = 0;

        /**

         * Unary minus.

         */

        virtual Item toNegated() const = 0;

        /**

         * @short Returns @c true if this value is signed. If @c false is

         * returned, the value is unsigned.

         *

         * For float and decimal values, @c xs:double, @c xs:float and @c

         * xs:decimal, the code asserts and behavior is undefined.

         */

        virtual bool isSigned() const = 0;

    protected:

        /**

         * @short Implements @c fn:round() for types implemented with floating

         * point.

         *

         * MS Windows and at least IRIX does not have C99's nearbyint() function(see the man

         * page), so we reinvent it.

         */

        static xsDouble roundFloat(const xsDouble val);

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif