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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_AxisStep_H
53 #define Patternist_AxisStep_H
55 #include <private/qemptycontainer_p.h>
56 #include <private/qitem_p.h>
65 * @short A step in a path expression that with an axis and a node test evaluates
66 * to a sequence of nodes from the context item.
68 * @author Frans Englich <frans.englich@nokia.com>
69 * @ingroup Patternist_expressions
71 class Q_AUTOTEST_EXPORT AxisStep : public EmptyContainer
74 AxisStep(const QXmlNodeModelIndex::Axis axis,
75 const ItemType::Ptr &nodeTest);
77 virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &) const;
78 virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
81 * Returns @p node if it matches the node test this step is using, otherwise @c null.
83 inline Item mapToItem(const QXmlNodeModelIndex &node,
84 const DynamicContext::Ptr &context) const;
86 virtual SequenceType::List expectedOperandTypes() const;
87 virtual SequenceType::Ptr staticType() const;
90 * Rewrites to ParentNodeAxis, if possible.
92 virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
93 const SequenceType::Ptr &reqType);
96 * @returns always BuiltinTypes::node;
98 virtual ItemType::Ptr expectedContextItemType() const;
100 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
102 virtual Properties properties() const;
105 * @returns the axis this step is using.
107 QXmlNodeModelIndex::Axis axis() const;
110 * @returns the node test this step is using.
112 inline ItemType::Ptr nodeTest() const
117 void setNodeTest(const ItemType::Ptr &nev)
123 * @short Prints the EBNF name corresponding to @p axis.
125 * For instance, for QXmlNodeModelIndex::Child, "child" is returned.
127 * Apart from being used in this class, it is used in the SDK.
129 static QString axisName(const QXmlNodeModelIndex::Axis axis);
131 virtual ID id() const;
132 virtual PatternPriority patternPriority() const;
134 inline void setAxis(const QXmlNodeModelIndex::Axis newAxis);
137 typedef QExplicitlySharedDataPointer<const AxisStep> ConstPtr;
139 static const QXmlNodeModelIndex::NodeKind s_whenAxisNodeKindEmpty[];
142 * @returns @c true when the axis @p axis and a node test testing node of
143 * type @p nodeKind always produces an empty sequence. One such example
144 * is <tt>attribute::comment()</tt>.
146 static bool isAlwaysEmpty(const QXmlNodeModelIndex::Axis axis,
147 const QXmlNodeModelIndex::NodeKind nodeKind);
150 * The reason this variable is mutable, is that in the case of XSL-T patterns,
151 * we do quite some reordering.
153 QXmlNodeModelIndex::Axis m_axis;
154 ItemType::Ptr m_nodeTest;
157 void AxisStep::setAxis(const QXmlNodeModelIndex::Axis newAxis)