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#include "qboolean_p.h"
41#include "qcommonsequencetypes_p.h"
42#include "qcommonvalues_p.h"
43#include "qliteral_p.h"
44
45#include "qinstanceof_p.h"
46
47QT_BEGIN_NAMESPACE
48
49using namespace QPatternist;
50
51InstanceOf::InstanceOf(const Expression::Ptr &operand,
52 const SequenceType::Ptr &tType) : SingleContainer(operand)
53 , m_targetType(tType)
54{
55 Q_ASSERT(m_targetType);
56}
57
58bool InstanceOf::evaluateEBV(const DynamicContext::Ptr &context) const
59{
60 const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));
61 Item item(it->next());
62 unsigned int count = 1;
63
64 if(!item)
65 return m_targetType->cardinality().allowsEmpty();
66
67 do
68 {
69 if(!m_targetType->itemType()->itemMatches(item))
70 return false;
71
72 if(count == 2 && !m_targetType->cardinality().allowsMany())
73 return false;
74
75 item = it->next();
76 ++count;
77 } while(item);
78
79 return true;
80}
81
82Expression::Ptr InstanceOf::compress(const StaticContext::Ptr &context)
83{
84 const Expression::Ptr me(SingleContainer::compress(context));
85
86 if(me != this || m_operand->has(prop: DisableTypingDeduction))
87 return me;
88
89 const SequenceType::Ptr opType(m_operand->staticType());
90 const ItemType::Ptr targetType(m_targetType->itemType());
91 const ItemType::Ptr operandType(opType->itemType());
92
93 if(m_targetType->cardinality().isMatch(other: opType->cardinality()))
94 {
95 if(*operandType == *CommonSequenceTypes::Empty || targetType->xdtTypeMatches(other: operandType))
96 return wrapLiteral(item: CommonValues::BooleanTrue, context, r: this);
97 else if(!operandType->xdtTypeMatches(other: targetType))
98 return wrapLiteral(item: CommonValues::BooleanFalse, context, r: this);
99 }
100 /* Optimization: rule out the case where instance of will always fail. */
101
102 return me;
103}
104
105SequenceType::Ptr InstanceOf::targetType() const
106{
107 return m_targetType;
108}
109
110SequenceType::Ptr InstanceOf::staticType() const
111{
112 return CommonSequenceTypes::ExactlyOneBoolean;
113}
114
115SequenceType::List InstanceOf::expectedOperandTypes() const
116{
117 SequenceType::List result;
118 result.append(t: CommonSequenceTypes::ZeroOrMoreItems);
119 return result;
120}
121
122ExpressionVisitorResult::Ptr InstanceOf::accept(const ExpressionVisitor::Ptr &visitor) const
123{
124 return visitor->visit(this);
125}
126
127QT_END_NAMESPACE
128

source code of qtxmlpatterns/src/xmlpatterns/expr/qinstanceof.cpp