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39
40//
41// W A R N I N G
42// -------------
43//
44// This file is not part of the Qt API. It exists purely as an
45// implementation detail. This header file may change from version to
46// version without notice, or even be removed.
47//
48// We mean it.
49
50#ifndef Patternist_ValueComparison_H
51#define Patternist_ValueComparison_H
52
53#include <private/qatomiccomparator_p.h>
54#include <private/qpaircontainer_p.h>
55#include <private/qcomparisonplatform_p.h>
56
57QT_BEGIN_NAMESPACE
58
59namespace QPatternist
60{
61
62 /**
63 * @short Implements XPath 2.0 value comparions, such as the <tt>eq</tt> operator.
64 *
65 * ComparisonPlatform is inherited with @c protected scope because ComparisonPlatform
66 * must access members of ValueComparison.
67 *
68 * @see <a href="http://www.w3.org/TR/xpath20/#id-value-comparisons">XML Path Language
69 * (XPath) 2.0, 3.5.1 Value Comparisons</a>
70 * @author Frans Englich <frans.englich@nokia.com>
71 * @ingroup Patternist_expressions
72 */
73 class Q_AUTOTEST_EXPORT ValueComparison
74 : public PairContainer, public ComparisonPlatform<ValueComparison, true>
75 {
76 public:
77 ValueComparison(const Expression::Ptr &op1,
78 const AtomicComparator::Operator op,
79 const Expression::Ptr &op2);
80 ~ValueComparison();
81
82 virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
83
84 virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
85 const SequenceType::Ptr &reqType);
86
87 /**
88 * @returns always CommonSequenceTypes::ExactlyOneBoolean
89 */
90 virtual SequenceType::Ptr staticType() const;
91
92 virtual SequenceType::List expectedOperandTypes() const;
93
94 /**
95 * @returns IDValueComparison
96 */
97 virtual ID id() const;
98
99 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
100 virtual QList<QExplicitlySharedDataPointer<OptimizationPass> > optimizationPasses() const;
101
102 /**
103 * Overridden to optimize case-insensitive compares.
104 */
105 virtual Expression::Ptr compress(const StaticContext::Ptr &context);
106
107 /**
108 * @returns the operator that this ValueComparison is using.
109 */
110 inline AtomicComparator::Operator operatorID() const
111 {
112 return m_operator;
113 }
114
115 /**
116 * It is considered that the string value from @p op1 will be compared against @p op2. This
117 * function determines whether the user intends the comparison to be case insensitive. If
118 * that is the case @c true is returned, and the operands are re-written appropriately.
119 *
120 * This is a helper function for Expression classes that compares strings.
121 *
122 * @see ComparisonPlatform::useCaseInsensitiveComparator()
123 */
124 static bool isCaseInsensitiveCompare(Expression::Ptr &op1, Expression::Ptr &op2);
125
126 private:
127 const AtomicComparator::Operator m_operator;
128 };
129}
130
131QT_END_NAMESPACE
132
133#endif
134

source code of qtxmlpatterns/src/xmlpatterns/expr/qvaluecomparison_p.h