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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_OrderBy_H
51#define Patternist_OrderBy_H
52
53#include <private/qatomiccomparator_p.h>
54#include <private/qcomparisonplatform_p.h>
55#include <private/qsinglecontainer_p.h>
56
57QT_BEGIN_NAMESPACE
58
59namespace QPatternist
60{
61 class ReturnOrderBy;
62
63 /**
64 * @short Performs the sorting by being a parent to ForClause.
65 *
66 * The child of the ForClause is a ReturnOrderBy expression, which collects
67 * the sort keys and values.
68 *
69 * @author Frans Englich <frans.englich@nokia.com>
70 * @ingroup Patternist_expressions
71 */
72 class OrderBy : public SingleContainer
73 {
74 public:
75 enum Stability
76 {
77 StableOrder,
78 UnstableOrder
79 };
80
81 /**
82 * This class is value based.
83 */
84 class OrderSpec : public ComparisonPlatform<OrderBy::OrderSpec,
85 true, /* Yes, issue errors. */
86 AtomicComparator::AsValueComparison>
87 {
88 public:
89 /**
90 * We want this guy to be public.
91 */
92 using ComparisonPlatform<OrderBy::OrderSpec, true, AtomicComparator::AsValueComparison>::detailedFlexibleCompare;
93
94 typedef QVector<OrderSpec> Vector;
95
96 enum Direction
97 {
98 Ascending,
99 Descending
100 };
101
102 /**
103 * @short Default constructor, which is needed by QVector.
104 */
105 inline OrderSpec()
106 : direction(Ascending),
107 orderingEmptySequence(StaticContext::Greatest)
108 {
109 }
110
111 inline OrderSpec(const Direction dir,
112 const StaticContext::OrderingEmptySequence orderingEmpty) : direction(dir),
113 orderingEmptySequence(orderingEmpty)
114 {
115 }
116
117 void prepare(const Expression::Ptr &source,
118 const StaticContext::Ptr &context);
119
120 const SourceLocationReflection *actualReflection() const
121 {
122 return m_expr.data();
123 }
124
125 private:
126 Expression::Ptr m_expr;
127
128 public:
129 /**
130 * We place these afterwards, such that m_expr gets aligned at the
131 * start of the address.
132 */
133 Direction direction;
134
135 StaticContext::OrderingEmptySequence orderingEmptySequence;
136
137 inline AtomicComparator::Operator operatorID() const
138 {
139 return orderingEmptySequence == StaticContext::Least ? AtomicComparator::OperatorLessThanNaNLeast
140 : AtomicComparator::OperatorLessThanNaNGreatest;
141 }
142
143 };
144
145 OrderBy(const Stability stability,
146 const OrderSpec::Vector &orderSpecs,
147 const Expression::Ptr &operand,
148 ReturnOrderBy *const returnOrderBy);
149
150 virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const;
151 virtual SequenceType::Ptr staticType() const;
152 virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
153 const SequenceType::Ptr &reqType);
154 virtual Expression::Ptr compress(const StaticContext::Ptr &context);
155 virtual SequenceType::List expectedOperandTypes() const;
156 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
157
158 inline Item::Iterator::Ptr mapToSequence(const Item &i,
159 const DynamicContext::Ptr &context) const;
160 virtual Properties properties() const;
161
162 private:
163 /**
164 * Needed when calling makeSequenceMappingIterator().
165 */
166 typedef QExplicitlySharedDataPointer<const OrderBy> ConstPtr;
167
168 const Stability m_stability;
169 OrderSpec::Vector m_orderSpecs;
170 ReturnOrderBy *const m_returnOrderBy;
171 };
172
173 /* TODO Q_DECLARE_TYPEINFO(OrderBy::OrderSpec, Q_MOVABLE_TYPE); Breaks,
174 * probably because it's nested. */
175}
176
177QT_END_NAMESPACE
178
179#endif
180

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