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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_TokenSource_H

#define Patternist_TokenSource_H

#include "qatomiccomparator_p.h"

#include "qatomicmathematician_p.h"

#include "qcombinenodes_p.h"

#include "qfunctionargument_p.h"

#include "qitem_p.h"

#include "qitemtype_p.h"

#include "qorderby_p.h"

#include "qpath_p.h"

#include "qquerytransformparser_p.h"

#include "qvalidate_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

template<typename T> class QQueue;

namespace QPatternist

{

    /**

     * @short A union of all the enums the parser uses.

     */

    union EnumUnion

    {

        AtomicComparator::Operator              valueOperator;

        AtomicMathematician::Operator           mathOperator;

        CombineNodes::Operator                  combinedNodeOp;

        QXmlNodeModelIndex::Axis                axis;

        QXmlNodeModelIndex::DocumentOrder       nodeOperator;

        StaticContext::BoundarySpacePolicy      boundarySpacePolicy;

        StaticContext::ConstructionMode         constructionMode;

        StaticContext::OrderingEmptySequence    orderingEmptySequence;

        StaticContext::OrderingMode             orderingMode;

        OrderBy::OrderSpec::Direction           sortDirection;

        Validate::Mode                          validationMode;

        VariableSlotID                          slot;

        int                                     tokenizerPosition;

        qint16                                  zeroer;

        bool                                    Bool;

        xsDouble                                Double;

        Path::Kind                              pathKind;

    };

    /**

     * @short Base class for components that needs to return tokens.

     *

     * TokenSource represents a stream of Token instances. The end

     * is reached when readNext() returns a Token constructed with

     * END_OF_FILE.

     *

     * @see <a href="http://www.w3.org/TR/xquery-xpath-parsing/">Building a

     * Tokenizer for XPath or XQuery</a>

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

     */

    class TokenSource : public QSharedData

    {

    public:

        /**

         * typedef for the enum Bison generates that contains

         * the token symbols.

         */

        typedef yytokentype TokenType;

        /**

         * Represents a token by carrying its name and value.

         */

        class Token

        {

        public:

            /**

             * Constructs an invalid Token. This default constructor

             * is need in Qt's container classes.

             */

            inline Token() {}

            inline Token(const TokenType t) : type(t) {}

            inline Token(const TokenType t, const QString &val) : type(t), value(val) {}

            bool hasError() const

            {

                return type == ERROR;

            }

            TokenType type;

            QString value;

        };

        typedef QExplicitlySharedDataPointer<TokenSource> Ptr;

        typedef QQueue<Ptr> Queue;

        /**

         * The C++ compiler cannot synthesize it when we use the

         * Q_DISABLE_COPY() macro.

         */

        inline TokenSource()

        {

        }

        virtual ~TokenSource();

        /**

         * @returns the next token.

         */

            virtual Token nextToken(YYLTYPE *const sourceLocator) = 0;

    private:

        Q_DISABLE_COPY(TokenSource)

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif