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_UnlimitedContainer_H 51 #define Patternist_UnlimitedContainer_H 52 53 #include <QList> 54 #include <private/qexpression_p.h> 55 #include <private/qgenericsequencetype_p.h> 56 57 QT_BEGIN_NAMESPACE 58 59 namespace QPatternist 60 { 61 /** 62 * @short Base class for expressions that has any amount of operands. 63 * 64 * @author Frans Englich <frans.englich@nokia.com> 65 * @ingroup Patternist_expressions 66 */ 67 class UnlimitedContainer : public Expression 68 { 69 public: 70 /** 71 * Creates an UnlimitedContainer containing the operands @p operands. @p operands 72 * may be empty. 73 */ 74 UnlimitedContainer(const Expression::List &operands = Expression::List()); 75 76 virtual void setOperands(const Expression::List &list); 77 78 virtual Expression::List operands() const; 79 80 /** 81 * @note This function cannot be called before setOperands is called. 82 */ 83 virtual bool compressOperands(const StaticContext::Ptr &); 84 85 /** 86 * Tells how operandsUnionType() should compute the cardinality of 87 * its children. 88 * 89 * This type is public because of a bug in the HP-UX aCC compiler. 90 */ 91 enum CardinalityComputation 92 { 93 ProductOfCardinality, 94 UnionOfCardinality 95 }; 96 97 protected: 98 /** 99 * Computes and returns the union type of all the Expression instances 100 * in this Expression's operands. 101 * 102 * This implementation is placed inside because CardinalityComputation 103 * can't be referenced from the outside(in conforming compilers). 104 */ 105 template<CardinalityComputation suppliedCard> 106 inline operandsUnionType()107 SequenceType::Ptr operandsUnionType() const 108 { 109 Q_ASSERT(suppliedCard == ProductOfCardinality || suppliedCard == UnionOfCardinality); 110 const Expression::List::const_iterator end(m_operands.constEnd()); 111 Expression::List::const_iterator it(m_operands.constBegin()); 112 113 /* Load the first one, and jump over it in the loop. */ 114 SequenceType::Ptr t(m_operands.first()->staticType()); 115 ItemType::Ptr type(t->itemType()); 116 Cardinality card(t->cardinality()); 117 ++it; 118 119 for(; it != end; ++it) 120 { 121 t = (*it)->staticType(); 122 type |= t->itemType(); 123 124 /* Since this function is a template function, it doesn't 125 * hurt performance that this test is inside the loop. */ 126 if(suppliedCard == ProductOfCardinality) 127 card += t->cardinality(); 128 else 129 card |= t->cardinality(); 130 } 131 132 return makeGenericSequenceType(type, card); 133 } 134 135 Expression::List m_operands; 136 }; 137 138 139 } 140 141 QT_END_NAMESPACE 142 143 #endif 144