summaryrefslogtreecommitdiffstats
path: root/src/xmlpatterns/expr/qaxisstep_p.h
blob: 8f2ae27e75b7a33bd846fe6a8112b81cbead3268 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.

#ifndef Patternist_AxisStep_H
#define Patternist_AxisStep_H

#include "qemptycontainer_p.h"
#include "qitem_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{
    /**
     * @short A step in a path expression that with an axis and a node test evaluates
     * to a sequence of nodes from the context item.
     *
     * @author Frans Englich <frans.englich@nokia.com>
     * @ingroup Patternist_expressions
     */
    class Q_AUTOTEST_EXPORT AxisStep : public EmptyContainer
    {
    public:
        AxisStep(const QXmlNodeModelIndex::Axis axis,
                 const ItemType::Ptr &nodeTest);

        virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &) const;
        virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;

        /**
         * Returns @p node if it matches the node test this step is using, otherwise @c null.
         */
        inline Item mapToItem(const QXmlNodeModelIndex &node,
                              const DynamicContext::Ptr &context) const;

        virtual SequenceType::List expectedOperandTypes() const;
        virtual SequenceType::Ptr staticType() const;

        /**
         * Rewrites to ParentNodeAxis, if possible.
         */
        virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
                                          const SequenceType::Ptr &reqType);

        /**
         * @returns always BuiltinTypes::node;
         */
        virtual ItemType::Ptr expectedContextItemType() const;

        virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;

        virtual Properties properties() const;

        /**
         * @returns the axis this step is using.
         */
        QXmlNodeModelIndex::Axis axis() const;

        /**
         * @returns the node test this step is using.
         */
        inline ItemType::Ptr nodeTest() const
        {
            return m_nodeTest;
        }

        void setNodeTest(const ItemType::Ptr &nev)
        {
            m_nodeTest = nev;
        }

        /**
         * @short Prints the EBNF name corresponding to @p axis.
         *
         * For instance, for QXmlNodeModelIndex::Child, "child" is returned.
         *
         * Apart from being used in this class, it is used in the SDK.
         */
        static QString axisName(const QXmlNodeModelIndex::Axis axis);

        virtual ID id() const;
        virtual PatternPriority patternPriority() const;

        inline void setAxis(const QXmlNodeModelIndex::Axis newAxis);

    private:
        typedef QExplicitlySharedDataPointer<const AxisStep> ConstPtr;

        static const QXmlNodeModelIndex::NodeKind s_whenAxisNodeKindEmpty[];

        /**
         * @returns @c true when the axis @p axis and a node test testing node of
         * type @p nodeKind always produces an empty sequence. One such example
         * is <tt>attribute::comment()</tt>.
         */
        static bool isAlwaysEmpty(const QXmlNodeModelIndex::Axis axis,
                                  const QXmlNodeModelIndex::NodeKind nodeKind);

        /**
         * The reason this variable is mutable, is that in the case of XSL-T patterns,
         * we do quite some reordering.
         */
        QXmlNodeModelIndex::Axis    m_axis;
        ItemType::Ptr               m_nodeTest;
    };

    void AxisStep::setAxis(const QXmlNodeModelIndex::Axis newAxis)
    {
        m_axis = newAxis;
    }

}

QT_END_NAMESPACE

QT_END_HEADER

#endif