1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2015 The Qt Company Ltd. 4 ** Contact: http://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 http://www.qt.io/terms-conditions. For further 15 ** information use the contact form at http://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 2.1 or version 3 as published by the Free 20 ** Software Foundation and appearing in the file LICENSE.LGPLv21 and 21 ** LICENSE.LGPLv3 included in the packaging of this file. Please review the 22 ** following information to ensure the GNU Lesser General Public License 23 ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and 24 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. 25 ** 26 ** As a special exception, The Qt Company gives you certain additional 27 ** rights. These rights are described in The Qt Company LGPL Exception 28 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. 29 ** 30 ** GNU General Public License Usage 31 ** Alternatively, this file may be used under the terms of the GNU 32 ** General Public License version 3.0 as published by the Free Software 33 ** Foundation and appearing in the file LICENSE.GPL included in the 34 ** packaging of this file. Please review the following information to 35 ** ensure the GNU General Public License version 3.0 requirements will be 36 ** met: http://www.gnu.org/copyleft/gpl.html. 37 ** 38 ** $QT_END_LICENSE$ 39 ** 40 ****************************************************************************/ 41 42 // 43 // W A R N I N G 44 // ------------- 45 // 46 // This file is not part of the Qt API. It exists purely as an 47 // implementation detail. This header file may change from version to 48 // version without notice, or even be removed. 49 // 50 // We mean it. 51 52 #ifndef Patternist_EmptySequenceType_H 53 #define Patternist_EmptySequenceType_H 54 55 #include "qatomictype_p.h" 56 #include "qsequencetype_p.h" 57 58 QT_BEGIN_HEADER 59 60 QT_BEGIN_NAMESPACE 61 62 namespace QPatternist 63 { 64 65 /** 66 * @short Represents the <tt>empty-sequence()</tt> type. 67 * 68 * @ingroup Patternist_types 69 * @author Frans Englich <frans.englich@nokia.com> 70 */ 71 class EmptySequenceType : public ItemType, 72 public SequenceType 73 { 74 public: 75 typedef QExplicitlySharedDataPointer<EmptySequenceType> Ptr; 76 77 /** 78 * Possibly surprisingly, this function also returns true for the @c none type. 79 * 80 * @returns @c true if @p other is NoneType or EmptySequenceType, otherwise @c false. 81 */ 82 virtual bool xdtTypeMatches(const ItemType::Ptr &other) const; 83 84 /** 85 * @returns always @c false 86 */ 87 virtual bool itemMatches(const Item &item) const; 88 89 /** 90 * @returns always "empty-sequence()" 91 */ 92 virtual QString displayName(const NamePool::Ptr &np) const; 93 94 virtual ItemType::Ptr xdtSuperType() const; 95 96 virtual bool isNodeType() const; 97 virtual bool isAtomicType() const; 98 99 /** 100 * @return always Cardinality::empty() 101 */ 102 virtual Cardinality cardinality() const; 103 104 /** 105 * @returns always 'this' since it is also an ItemType 106 */ 107 virtual ItemType::Ptr itemType() const; 108 109 /** 110 * @returns always @c xs:anyAtomicType 111 */ 112 virtual ItemType::Ptr atomizedType() const; 113 114 protected: 115 friend class CommonSequenceTypes; 116 EmptySequenceType(); 117 }; 118 } 119 120 QT_END_NAMESPACE 121 122 QT_END_HEADER 123 124 #endif 125