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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_ExternalVariableReference_H
51#define Patternist_ExternalVariableReference_H
52
53#include <private/qemptycontainer_p.h>
54
55QT_BEGIN_NAMESPACE
56
57namespace QPatternist
58{
59 /**
60 * @short A reference to an external variable.
61 *
62 * ExternalVariableReference does not sub-class VariableReference, because it
63 * works differently from how sub-classes of VariableReference do. This class
64 * uses DynamicContext::externalVariableLoader() for retrieving its value, while
65 * a VariableReference sub-class uses slots in the DynamicContext.
66 *
67 * @author Frans Englich <frans.englich@nokia.com>
68 * @ingroup Patternist_expressions
69 */
70 class ExternalVariableReference : public EmptyContainer
71 {
72 public:
73 ExternalVariableReference(const QXmlName &name,
74 const SequenceType::Ptr &type);
75
76 virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const;
77 virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const;
78 virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;
79
80 virtual SequenceType::Ptr staticType() const;
81
82 /**
83 * @returns always DisableElimination
84 */
85 virtual Expression::Properties properties() const;
86
87 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
88
89 private:
90 const QXmlName m_name;
91 const SequenceType::Ptr m_seqType;
92 };
93}
94
95QT_END_NAMESPACE
96
97#endif
98

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