/****************************************************************************

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtXmlPatterns module of the Qt Toolkit.

**

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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**

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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_PatternPlatform_H

#define Patternist_PatternPlatform_H

#include <QFlags>

#include <QRegExp>

#include "qfunctioncall_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Contains functionality for functions and expressions that

     * uses regular expressions.

     *

     * @ingroup Patternist_utils

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

     */

    class PatternPlatform : public FunctionCall

    {

    public:

        /**

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

         * XPath 2.0 Functions and Operators, 7.6.1.1 Flags</a>

         */

        enum Flag

        {

            /**

             * No flags are set. Default behavior is used.

             */

            NoFlags             = 0,

            /**

             * Flag @c s

             */

            DotAllMode          = 1,

            /**

             * Flag @c m

             */

            MultiLineMode       = 2,

            /**

             * Flag @c i

             */

            CaseInsensitive     = 4,

            /**

             * Flag @c x

             */

            SimplifyWhitespace  = 8

        };

        typedef QFlags<Flag> Flags;

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

        /**

         * Retrieves the pattern supplied in the arguments, taking care of compiling it,

         * settings its flags, and everything else required for getting it ready to use. If an error

         * occurs, an appropriate error is raised via @p context.

         */

        const QRegExp pattern(const DynamicContext::Ptr &context) const;

        /**

         * @returns the number of captures, also called parenthesized sub-expressions, the pattern has.

         *

         * If the pattern isn't precompiled, -1 is returned.

         */

        inline int captureCount() const;

        /**

         * @short Parses pattern 

         */

        static QRegExp parsePattern(const QString &pattern,

                                    const ReportContext::Ptr &context,

                                    const SourceLocationReflection *const location);

    protected:

        /**

         * @short This constructor is protected, because this class is supposed to be sub-classed.

         *

         * @param flagsPosition an index position specifying the operand containing the pattern

         * flags.

         */

        PatternPlatform(const qint8 flagsPosition);

    private:

        /**

         * Enum telling whether the flags, pattern, or both

         * have been compiled at compile time.

         */

        enum PreCompiledPart

        {

            NoPart          = 0,

            PatternPrecompiled     = 1,

            FlagsPrecompiled       = 2,

            FlagsAndPattern = PatternPrecompiled | FlagsPrecompiled

        };

        typedef QFlags<PreCompiledPart> PreCompiledParts;

        /**

         * @short Calls the public parsePattern() function and passes in @c

         * this as the location.

         */

        inline QRegExp parsePattern(const QString &pattern,

                                    const ReportContext::Ptr &context) const;

        Q_DISABLE_COPY(PatternPlatform)

        Flags parseFlags(const QString &flags,

                         const DynamicContext::Ptr &context) const;

        static void applyFlags(const Flags flags, QRegExp &pattern);

        /**

         * The parts that have been pre-compiled at compile time.

         */

        PreCompiledParts    m_compiledParts;

        Flags               m_flags;

        QRegExp             m_pattern;

        const qint8         m_flagsPosition;

    };

    inline int PatternPlatform::captureCount() const

    {

        if(m_compiledParts.testFlag(PatternPrecompiled))

            return m_pattern.numCaptures();

        else

            return -1;

    }

    Q_DECLARE_OPERATORS_FOR_FLAGS(PatternPlatform::Flags)

}

QT_END_NAMESPACE

QT_END_HEADER

#endif