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 55 QT_BEGIN_NAMESPACE 56 57 namespace 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 mapToItem(const Item & item,const DynamicContext::Ptr & context)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 map(const Item & item,const DynamicContext::Ptr & context)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 } 103 104 QT_END_NAMESPACE 105 106 #endif 107