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     2 **

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

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

     6 **

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

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    16 ** GNU Lesser General Public License Usage

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    38 ** $QT_END_LICENSE$

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    40 ****************************************************************************/

    41 

    42 //

    43 //  W A R N I N G

    44 //  -------------

    45 //

    46 // This file is not part of the Qt API.  It exists purely as an

    47 // implementation detail.  This header file may change from version to

    48 // version without notice, or even be removed.

    49 //

    50 // We mean it.

    51 

    52 #ifndef Patternist_ForClause_H

    53 #define Patternist_ForClause_H

    54 

    55 #include "qpaircontainer_p.h"

    56 

    57 QT_BEGIN_HEADER

    58 

    59 QT_BEGIN_NAMESPACE

    60 

    61 namespace QPatternist

    62 {

    63 

    64     /**

    65      * @short Implements XPath 2.0's @c for expression.

    66      *

    67      * @see <a href="http://www.w3.org/TR/xpath20/#id-for-expressions">XML Path Language

    68      * (XPath) 2.0, 3.7 For Expressions</a>

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

    70      * @ingroup Patternist_expressions

    71      */

    72     class ForClause : public PairContainer

    73     {

    74     public:

    75         /**

    76          * If @p positionSlot is -1, no positional variable will be used.

    77          */

    78         ForClause(const VariableSlotID varSlot,

    79                   const Expression::Ptr &bindingSequence,

    80                   const Expression::Ptr &returnExpression,

    81                   const VariableSlotID positionSlot);

    82 

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

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

    85         virtual void evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const;

    86 

    87         virtual SequenceType::Ptr staticType() const;

    88         virtual SequenceType::List expectedOperandTypes() const;

    89         virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,

    90                                           const SequenceType::Ptr &reqType);

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

    92         virtual QList<QExplicitlySharedDataPointer<OptimizationPass> > optimizationPasses() const;

    93 

    94         inline Item mapToItem(const Item &item,

    95                               const DynamicContext::Ptr &context) const;

    96         virtual ID id() const;

    97         inline Item::Iterator::Ptr mapToSequence(const Item &item,

    98                                                  const DynamicContext::Ptr &context) const;

    99 

   100         /**

   101          * Sets m_allowsMany properly.

   102          */

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

   104 

   105     private:

   106         inline void riggPositionalVariable(const DynamicContext::Ptr &context,

   107                                            const Item::Iterator::Ptr &source) const;

   108         typedef QExplicitlySharedDataPointer<const ForClause> ConstPtr;

   109         const VariableSlotID m_varSlot;

   110         const VariableSlotID m_positionSlot;

   111         /**

   112          * Initialized to @c false. This default is always safe.

   113          */

   114         bool m_allowsMany;

   115     };

   116 }

   117 

   118 QT_END_NAMESPACE

   119 

   120 QT_END_HEADER

   121 

   122 #endif