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

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

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    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_Literal_H

    53 #define Patternist_Literal_H

    54 

    55 #include "qemptycontainer_p.h"

    56 

    57 QT_BEGIN_HEADER

    58 

    59 QT_BEGIN_NAMESPACE

    60 

    61 namespace QPatternist

    62 {

    63     /**

    64      * @short Houses an AtomicValue, making it available as an Expression.

    65      *

    66      * This is not only literals that can be created via the XQuery syntax(strings and numbers), but

    67      * all other atomic values, such as <tt>xs:date</tt> or <tt>xs:time</tt>.

    68      *

    69      * @see <a href="http://www.w3.org/TR/xquery/#id-literals">XQuery 1.0: An XML Query Language,

    70      * 3.1.1 Literals</a>

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

    72      * @ingroup Patternist_expressions

    73      */

    74     class Literal : public EmptyContainer

    75     {

    76     public:

    77         /**

    78          * Creates a Literal that represents @p item.

    79          *

    80          * @param item must be non-null and cannot be a QXmlNodeModelIndex.

    81          */

    82         Literal(const Item &item);

    83 

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

    85         virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;

    86         void evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const;

    87 

    88         virtual SequenceType::Ptr staticType() const;

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

    90         virtual ID id() const;

    91         virtual QString description() const;

    92 

    93         /**

    94          * @returns Expression::DisableElimination and Expression::IsEvaluated

    95          */

    96         virtual Properties properties() const;

    97 

    98         /**

    99          * Declaring the return value of this function a const reference, leads

   100          * to crashes in patternistview, for a to me unknown reason.

   101          */

   102         inline Item item() const

   103         {

   104             return m_item;

   105         }

   106 

   107     private:

   108         const Item m_item;

   109     };

   110 

   111     /**

   112      * @short Creates a Literal that wraps @p item, and returns it.

   113      *

   114      * This simplifies code. Instead of writing:

   115      *

   116      * @code

   117      * Expression::Ptr(new Literal(item));

   118      * @endcode

   119      *

   120      * One can write:

   121      *

   122      * @code

   123      * wrapLiteral(item);

   124      * @endcode

   125      *

   126      * This function is not declared static, because it breaks the build on

   127      * at least aix-xlc-64.

   128      *

   129      * @relates Literal

   130      */

   131     inline Expression::Ptr wrapLiteral(const Item &item,

   132                                        const StaticContext::Ptr &context,

   133                                        const SourceLocationReflection *const r)

   134     {

   135         Q_ASSERT(item);

   136 

   137         const Expression::Ptr retval(new Literal(item));

   138         context->addLocation(retval.data(), context->locationFor(r));

   139 

   140         return retval;

   141     }

   142 }

   143 

   144 QT_END_NAMESPACE

   145 

   146 QT_END_HEADER

   147 

   148 #endif