1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2016 The Qt Company Ltd. 4 ** Contact: https://www.qt.io/licensing/ 5 ** 6 ** This file is part of the QtXmlPatterns module of the Qt Toolkit. 7 ** 8 ** $QT_BEGIN_LICENSE:LGPL$ 9 ** Commercial License Usage 10 ** Licensees holding valid commercial Qt licenses may use this file in 11 ** accordance with the commercial license agreement provided with the 12 ** Software or, alternatively, in accordance with the terms contained in 13 ** a written agreement between you and The Qt Company. For licensing terms 14 ** and conditions see https://www.qt.io/terms-conditions. For further 15 ** information use the contact form at https://www.qt.io/contact-us. 16 ** 17 ** GNU Lesser General Public License Usage 18 ** Alternatively, this file may be used under the terms of the GNU Lesser 19 ** General Public License version 3 as published by the Free Software 20 ** Foundation and appearing in the file LICENSE.LGPL3 included in the 21 ** packaging of this file. Please review the following information to 22 ** ensure the GNU Lesser General Public License version 3 requirements 23 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. 24 ** 25 ** GNU General Public License Usage 26 ** Alternatively, this file may be used under the terms of the GNU 27 ** General Public License version 2.0 or (at your option) the GNU General 28 ** Public license version 3 or any later version approved by the KDE Free 29 ** Qt Foundation. The licenses are as published by the Free Software 30 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 31 ** included in the packaging of this file. Please review the following 32 ** information to ensure the GNU General Public License requirements will 33 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and 34 ** https://www.gnu.org/licenses/gpl-3.0.html. 35 ** 36 ** $QT_END_LICENSE$ 37 ** 38 ****************************************************************************/ 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 */ nodeTest()108 inline ItemType::Ptr nodeTest() const 109 { 110 return m_nodeTest; 111 } 112 setNodeTest(const ItemType::Ptr & nev)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 setAxis(const QXmlNodeModelIndex::Axis newAxis)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