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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_ValueComparison_H

    53 #define Patternist_ValueComparison_H

    54 

    55 #include "qatomiccomparator_p.h"

    56 #include "qpaircontainer_p.h"

    57 #include "qcomparisonplatform_p.h"

    58 

    59 QT_BEGIN_HEADER

    60 

    61 QT_BEGIN_NAMESPACE

    62 

    63 namespace QPatternist

    64 {

    65 

    66     /**

    67      * @short Implements XPath 2.0 value comparions, such as the <tt>eq</tt> operator.

    68      *

    69      * ComparisonPlatform is inherited with @c protected scope because ComparisonPlatform

    70      * must access members of ValueComparison.

    71      *

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

    73      * (XPath) 2.0, 3.5.1 Value Comparisons</a>

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

    75      * @ingroup Patternist_expressions

    76      */

    77     class ValueComparison : public PairContainer,

    78                             public ComparisonPlatform<ValueComparison, true>

    79     {

    80     public:

    81         ValueComparison(const Expression::Ptr &op1,

    82                         const AtomicComparator::Operator op,

    83                         const Expression::Ptr &op2);

    84 

    85         virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;

    86 

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

    88                                           const SequenceType::Ptr &reqType);

    89 

    90         /**

    91          * @returns always CommonSequenceTypes::ExactlyOneBoolean

    92          */

    93         virtual SequenceType::Ptr staticType() const;

    94 

    95         virtual SequenceType::List expectedOperandTypes() const;

    96 

    97         /**

    98          * @returns IDValueComparison

    99          */

   100         virtual ID id() const;

   101 

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

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

   104 

   105         /**

   106          * Overridden to optimize case-insensitive compares.

   107          */

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

   109 

   110         /**

   111          * @returns the operator that this ValueComparison is using.

   112          */

   113         inline AtomicComparator::Operator operatorID() const

   114         {

   115             return m_operator;

   116         }

   117 

   118         /**

   119          * It is considered that the string value from @p op1 will be compared against @p op2. This

   120          * function determines whether the user intends the comparison to be case insensitive. If

   121          * that is the case @c true is returned, and the operands are re-written appropriately.

   122          *

   123          * This is a helper function for Expression classes that compares strings.

   124          *

   125          * @see ComparisonPlatform::useCaseInsensitiveComparator()

   126          */

   127         static bool isCaseInsensitiveCompare(Expression::Ptr &op1, Expression::Ptr &op2);

   128 

   129     private:

   130         const AtomicComparator::Operator m_operator;

   131     };

   132 }

   133 

   134 QT_END_NAMESPACE

   135 

   136 QT_END_HEADER

   137 

   138 #endif