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
|
/****************************************************************************
**
** 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://www.qtsoftware.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_CastAs_H
#define Patternist_CastAs_H
#include "qsinglecontainer_p.h"
#include "qcastingplatform_p.h"
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
namespace QPatternist
{
/**
* @short Implements XPath 2.0's <tt>cast as</tt> expression.
*
* Implements the casting expression, such as <tt>'3' cast as xs:integer</tt>. This class also
* implements constructor functions, which are created in the ConstructorFunctionsFactory.
*
* CastAs uses CastingPlatform for carrying out the actual casting.
*
* @see <a href="http://www.w3.org/TR/xpath-functions/#casting">XQuery 1.0
* and XPath 2.0 Functions and Operators, 7 Casting</a>
* @see <a href="http://www.w3.org/TR/xpath20/#id-cast">XML Path Language
* (XPath) 2.0, 3.10.2 Cast</a>
* @author Frans Englich <fenglich@trolltech.com>
* @ingroup Patternist_expressions
*/
class CastAs : public SingleContainer,
public CastingPlatform<CastAs, true /* issueError */>
{
public:
/**
* @todo Wrong/old documentation
*
* Creates a cast expression for the type @p name via the schema type
* factory @p factory. This function is used by parser when creating
* 'cast to' expressions, and the ConstructorFunctionsFactory, when creating
* constructor functions.
*
* @param targetType the type which the CastAs should cast to
* @param source the operand to evaluate and then cast from
*/
CastAs(const Expression::Ptr &source,
const SequenceType::Ptr &targetType);
virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
virtual SequenceType::List expectedOperandTypes() const;
/**
* @returns a SequenceType where the ItemType is this CastAs's
* target type, as per targetType(), and the Cardinality is inferred from the
* source operand to reflect whether this CastAs always will evaluate to
* exactly-one or zero-or-one values.
*/
virtual SequenceType::Ptr staticType() const;
/**
* Overridden in order to check that casting to an abstract type
* is not attempted.
*/
virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
const SequenceType::Ptr &reqType);
/**
* If the target type is the same as the source type, it is rewritten
* to the operand.
*/
virtual Expression::Ptr compress(const StaticContext::Ptr &context);
virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
inline ItemType::Ptr targetType() const
{
return m_targetType->itemType();
}
inline SequenceType::Ptr targetSequenceType() const
{
return m_targetType;
}
private:
/**
* Performs casting to @c xs:QName. This case is special, and is always done at compile time.
*/
Expression::Ptr castToQName(const StaticContext::Ptr &context) const;
const SequenceType::Ptr m_targetType;
};
}
QT_END_NAMESPACE
QT_END_HEADER
#endif
|
