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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_EmptySequence_H
51#define Patternist_EmptySequence_H
52
53#include <private/qemptycontainer_p.h>
54
55QT_BEGIN_NAMESPACE
56
57namespace QPatternist
58{
59 /**
60 * @short Implements the value instance of empty sequence: <tt>()</tt>.
61 *
62 * @author Frans Englich <frans.englich@nokia.com>
63 * @ingroup Patternist_xdm
64 */
65 class EmptySequence : public EmptyContainer
66 {
67 public:
68 /**
69 * @short Creates an EmptySequence that is a replacement for @p
70 * replacementFor.
71 *
72 * @see EmptySequence()
73 */
74 static Expression::Ptr create(const Expression *const replacementFor,
75 const StaticContext::Ptr &context);
76
77
78 /**
79 * @short Creates an instance of EmptySequence.
80 *
81 * @note In most cases create() should be used, since it takes care of
82 * adjusting source location annotations.
83 *
84 * @see create()
85 */
86 inline EmptySequence()
87 {
88 }
89
90 virtual QString stringValue() const;
91
92 /**
93 * @returns always an empty iterator, an instance of EmptyIterator.
94 */
95 virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &) const;
96
97 /**
98 * @returns always @c null.
99 */
100 virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
101
102 /**
103 * Does nothing.
104 */
105 virtual void evaluateToSequenceReceiver(const DynamicContext::Ptr &) const;
106
107 /**
108 * @returns always @c false.
109 */
110 virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;
111
112 /**
113 * @returns always CommonSequenceTypes::Empty
114 */
115 virtual ItemType::Ptr type() const;
116
117 /**
118 * @returns always CommonSequenceTypes::Empty
119 */
120 virtual SequenceType::Ptr staticType() const;
121
122 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
123 virtual ID id() const;
124 virtual Properties properties() const;
125 };
126}
127
128QT_END_NAMESPACE
129
130#endif
131

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