summaryrefslogtreecommitdiffstats
path: root/src/xmlpatterns/expr/qpath_p.h
blob: 99c26c6f52d0e666eed3631b97a61d1b251d88cb (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
169
170
171
172
173
174
175
176
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** 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 either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/

//
//  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_Path_H
#define Patternist_Path_H

#include "qpaircontainer_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{

    /**
     * @short Implements the path expression, containing two steps, such as in <tt>html/body</tt>.
     *
     * @see <a href="http://www.w3.org/TR/xquery/#id-path-expressions">XQuery 1.0: An
     * XML Query Language, 3.2 Path Expressions</a>
     * @author Frans Englich <fenglich@trolltech.com>
     * @ingroup Patternist_expressions
     */
    class Path : public PairContainer
    {
    public:
        enum Kind
        {
            /**
             * This Path is a plain old path expression as found in XPath.
             * Sorting is performed, and atomics are disallowed as left
             * operand.
             */
            RegularPath = 1,

            /**
             * This Path emulates an @c xsl:for-each instruction. This means no
             * sorting of result, and atomics are allowed as left operand.
             */
            XSLTForEach,

            /**
             * This Path performs the iteration in an @c xsl:apply-templates
             * instruction. This means sorting, and atomics are disallowed
             * as left operand.
             */
            ForApplyTemplate
        };

        Path(const Expression::Ptr &operand1,
             const Expression::Ptr &operand2,
             const Kind kind = RegularPath);

        virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const;
        virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const;
        virtual void evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const;
        inline Item::Iterator::Ptr mapToSequence(const Item &item,
                                                 const DynamicContext::Ptr &context) const;

        virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
                                          const SequenceType::Ptr &reqType);

        virtual SequenceType::List expectedOperandTypes() const;

        /**
         * @returns the static type of the last step where the cardinality is multiplied with
         * the cardinality of the first step's cardinality.
         */
        virtual SequenceType::Ptr staticType() const;

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

        virtual Properties properties() const;

        virtual Expression::Ptr compress(const StaticContext::Ptr &context);

        /**
         * @returns the item type of the last step's static type.
         */
        virtual ItemType::Ptr newFocusType() const;

        virtual ID id() const;

        inline void setLast();

        inline Kind kind() const
        {
            return m_kind;
        }

    private:
        typedef QExplicitlySharedDataPointer<const Path> ConstPtr;

        /**
         * One might think this block exists for preventing multiple
         * NodeSortExpressions to be created. However, that is not an issue,
         * since NodeSortExpression optimizes this away anyway.
         *
         * The real reason is to avoid infinite recursion. When our typeCheck()
         * forwards on the type check to the just created
         * NodeSortExpression, it in turn calls typeCheck() on its child, which
         * is this Path. Rince and repeat.
         *
         * We only create node sorts when we're a regular path expression, and
         * not when standing in as a generic map expression. */
        bool        m_hasCreatedSorter;

        /**
         * Whether this path is the step. For instance, in <tt>a/b/c</tt>, the
         * last path has @c c as the right operand.
         */
        bool        m_isLast;

        bool        m_checkXPTY0018;
        const Kind  m_kind;
    };

    void Path::setLast()
    {
        m_isLast = true;
    }
}

QT_END_NAMESPACE

QT_END_HEADER

#endif