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_TruthPredicate_H
51#define Patternist_TruthPredicate_H
52
53#include <private/qgenericpredicate_p.h>
54
55QT_BEGIN_NAMESPACE
56
57namespace QPatternist
58{
59 /**
60 * @short A predicate which is optimized for filter expressions that
61 * are of type @c xs:boolean.
62 *
63 * @author Frans Englich <frans.englich@nokia.com>
64 * @ingroup Patternist_expressions
65 */
66 class TruthPredicate : public GenericPredicate
67 {
68 public:
69 /**
70 * Creates a TruthPredicate which filters the items from the @p sourceExpression
71 * through @p predicate.
72 *
73 * This constructor is protected. The proper way to create predicates is via the static
74 * create() function.
75 */
76 TruthPredicate(const Expression::Ptr &sourceExpression,
77 const Expression::Ptr &predicate);
78
79 inline Item mapToItem(const Item &item, const DynamicContext::Ptr &context) const
80 {
81 Q_ASSERT_X(false, Q_FUNC_INFO, "This is practically dead code because it never gets called in GenericPredicate, "
82 "which binds to its own mapToItem for completely legitime reasons.");
83 if(m_operand2->evaluateEBV(context))
84 return item;
85 else
86 return Item();
87 }
88
89 inline Item::Iterator::Ptr map(const Item &item,
90 const DynamicContext::Ptr &context) const
91 {
92 Q_ASSERT_X(false, Q_FUNC_INFO, "I don't expect this function to be called, for the same reasons as above.");
93 if(m_operand2->evaluateEBV(context))
94 return makeSingletonIterator(item);
95 else
96 return CommonValues::emptyIterator;
97 }
98
99 virtual SequenceType::List expectedOperandTypes() const;
100 virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
101 };
102}
103
104QT_END_NAMESPACE
105
106#endif
107

source code of qtxmlpatterns/src/xmlpatterns/expr/qtruthpredicate_p.h