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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.
52 #ifndef Patternist_ValueComparison_H
53 #define Patternist_ValueComparison_H
55 #include <private/qatomiccomparator_p.h>
56 #include <private/qpaircontainer_p.h>
57 #include <private/qcomparisonplatform_p.h>
67 * @short Implements XPath 2.0 value comparions, such as the <tt>eq</tt> operator.
69 * ComparisonPlatform is inherited with @c protected scope because ComparisonPlatform
70 * must access members of ValueComparison.
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
77 class ValueComparison : public PairContainer,
78 public ComparisonPlatform<ValueComparison, true>
81 ValueComparison(const Expression::Ptr &op1,
82 const AtomicComparator::Operator op,
83 const Expression::Ptr &op2);
85 virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
87 virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
88 const SequenceType::Ptr &reqType);
91 * @returns always CommonSequenceTypes::ExactlyOneBoolean
93 virtual SequenceType::Ptr staticType() const;
95 virtual SequenceType::List expectedOperandTypes() const;
98 * @returns IDValueComparison
100 virtual ID id() const;
102 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
103 virtual QList<QExplicitlySharedDataPointer<OptimizationPass> > optimizationPasses() const;
106 * Overridden to optimize case-insensitive compares.
108 virtual Expression::Ptr compress(const StaticContext::Ptr &context);
111 * @returns the operator that this ValueComparison is using.
113 inline AtomicComparator::Operator operatorID() const
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.
123 * This is a helper function for Expression classes that compares strings.
125 * @see ComparisonPlatform::useCaseInsensitiveComparator()
127 static bool isCaseInsensitiveCompare(Expression::Ptr &op1, Expression::Ptr &op2);
130 const AtomicComparator::Operator m_operator;