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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_AxisStep_H |
51 | #define Patternist_AxisStep_H |
52 | |
53 | #include <private/qemptycontainer_p.h> |
54 | #include <private/qitem_p.h> |
55 | |
56 | QT_BEGIN_NAMESPACE |
57 | |
58 | namespace QPatternist |
59 | { |
60 | /** |
61 | * @short A step in a path expression that with an axis and a node test evaluates |
62 | * to a sequence of nodes from the context item. |
63 | * |
64 | * @author Frans Englich <frans.englich@nokia.com> |
65 | * @ingroup Patternist_expressions |
66 | */ |
67 | class Q_AUTOTEST_EXPORT AxisStep : public EmptyContainer |
68 | { |
69 | public: |
70 | AxisStep(const QXmlNodeModelIndex::Axis axis, |
71 | const ItemType::Ptr &nodeTest); |
72 | |
73 | virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &) const; |
74 | virtual Item evaluateSingleton(const DynamicContext::Ptr &) const; |
75 | |
76 | /** |
77 | * Returns @p node if it matches the node test this step is using, otherwise @c null. |
78 | */ |
79 | inline Item mapToItem(const QXmlNodeModelIndex &node, |
80 | const DynamicContext::Ptr &context) const; |
81 | |
82 | virtual SequenceType::List expectedOperandTypes() const; |
83 | virtual SequenceType::Ptr staticType() const; |
84 | |
85 | /** |
86 | * Rewrites to ParentNodeAxis, if possible. |
87 | */ |
88 | virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context, |
89 | const SequenceType::Ptr &reqType); |
90 | |
91 | /** |
92 | * @returns always BuiltinTypes::node; |
93 | */ |
94 | virtual ItemType::Ptr expectedContextItemType() const; |
95 | |
96 | virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const; |
97 | |
98 | virtual Properties properties() const; |
99 | |
100 | /** |
101 | * @returns the axis this step is using. |
102 | */ |
103 | QXmlNodeModelIndex::Axis axis() const; |
104 | |
105 | /** |
106 | * @returns the node test this step is using. |
107 | */ |
108 | inline ItemType::Ptr nodeTest() const |
109 | { |
110 | return m_nodeTest; |
111 | } |
112 | |
113 | void setNodeTest(const ItemType::Ptr &nev) |
114 | { |
115 | m_nodeTest = nev; |
116 | } |
117 | |
118 | /** |
119 | * @short Prints the EBNF name corresponding to @p axis. |
120 | * |
121 | * For instance, for QXmlNodeModelIndex::Child, "child" is returned. |
122 | * |
123 | * Apart from being used in this class, it is used in the SDK. |
124 | */ |
125 | static QString axisName(const QXmlNodeModelIndex::Axis axis); |
126 | |
127 | virtual ID id() const; |
128 | virtual PatternPriority patternPriority() const; |
129 | |
130 | inline void setAxis(const QXmlNodeModelIndex::Axis newAxis); |
131 | |
132 | private: |
133 | typedef QExplicitlySharedDataPointer<const AxisStep> ConstPtr; |
134 | |
135 | static const QXmlNodeModelIndex::NodeKind s_whenAxisNodeKindEmpty[]; |
136 | |
137 | /** |
138 | * @returns @c true when the axis @p axis and a node test testing node of |
139 | * type @p nodeKind always produces an empty sequence. One such example |
140 | * is <tt>attribute::comment()</tt>. |
141 | */ |
142 | static bool isAlwaysEmpty(const QXmlNodeModelIndex::Axis axis, |
143 | const QXmlNodeModelIndex::NodeKind nodeKind); |
144 | |
145 | /** |
146 | * The reason this variable is mutable, is that in the case of XSL-T patterns, |
147 | * we do quite some reordering. |
148 | */ |
149 | QXmlNodeModelIndex::Axis m_axis; |
150 | ItemType::Ptr m_nodeTest; |
151 | }; |
152 | |
153 | void AxisStep::setAxis(const QXmlNodeModelIndex::Axis newAxis) |
154 | { |
155 | m_axis = newAxis; |
156 | } |
157 | |
158 | } |
159 | |
160 | QT_END_NAMESPACE |
161 | |
162 | #endif |
163 | |