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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_ExternalVariableReference_H
53 #define Patternist_ExternalVariableReference_H
55 #include <private/qemptycontainer_p.h>
64 * @short A reference to an external variable.
66 * ExternalVariableReference does not sub-class VariableReference, because it
67 * works differently from how sub-classes of VariableReference do. This class
68 * uses DynamicContext::externalVariableLoader() for retrieving its value, while
69 * a VariableReference sub-class uses slots in the DynamicContext.
71 * @author Frans Englich <frans.englich@nokia.com>
72 * @ingroup Patternist_expressions
74 class ExternalVariableReference : public EmptyContainer
77 ExternalVariableReference(const QXmlName &name,
78 const SequenceType::Ptr &type);
80 virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const;
81 virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const;
82 virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;
84 virtual SequenceType::Ptr staticType() const;
87 * @returns always DisableElimination
89 virtual Expression::Properties properties() const;
91 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
94 const QXmlName m_name;
95 const SequenceType::Ptr m_seqType;