| /**************************************************************************** |
| ** |
| ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). |
| ** All rights reserved. |
| ** Contact: Nokia Corporation (qt-info@nokia.com) |
| ** |
| ** This file is part of the QtXmlPatterns module of the Qt Toolkit. |
| ** |
| ** $QT_BEGIN_LICENSE:LGPL$ |
| ** GNU Lesser General Public License Usage |
| ** This file may be used under the terms of the GNU Lesser General Public |
| ** License version 2.1 as published by the Free Software Foundation and |
| ** appearing in the file LICENSE.LGPL included in the packaging of this |
| ** file. Please review the following information to ensure the GNU Lesser |
| ** General Public License version 2.1 requirements will be met: |
| ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
| ** |
| ** In addition, as a special exception, Nokia gives you certain additional |
| ** rights. These rights are described in the Nokia Qt LGPL Exception |
| ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
| ** |
| ** GNU General Public License Usage |
| ** Alternatively, this file may be used under the terms of the GNU General |
| ** Public License version 3.0 as published by the Free Software Foundation |
| ** and appearing in the file LICENSE.GPL included in the packaging of this |
| ** file. Please review the following information to ensure the GNU General |
| ** Public License version 3.0 requirements will be met: |
| ** http://www.gnu.org/copyleft/gpl.html. |
| ** |
| ** Other Usage |
| ** Alternatively, this file may be used in accordance with the terms and |
| ** conditions contained in a signed written agreement between you and Nokia. |
| ** |
| ** |
| ** |
| ** |
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| ** $QT_END_LICENSE$ |
| ** |
| ****************************************************************************/ |
| |
| // |
| // W A R N I N G |
| // ------------- |
| // |
| // This file is not part of the Qt API. It exists purely as an |
| // implementation detail. This header file may change from version to |
| // version without notice, or even be removed. |
| // |
| // We mean it. |
| |
| #ifndef Patternist_NoneType_H |
| #define Patternist_NoneType_H |
| |
| #include "qatomictype_p.h" |
| #include "qsequencetype_p.h" |
| |
| QT_BEGIN_HEADER |
| |
| QT_BEGIN_NAMESPACE |
| |
| namespace QPatternist |
| { |
| |
| /** |
| * @short Represents the special <tt>none</tt> type. |
| * |
| * @ingroup Patternist_types |
| * @see <a href="http://www.w3.org/TR/xquery-semantics/#sec_content_models">XQuery 1.0 and |
| * XPath 2.0 Formal Semantics, 2.4.3 Content models</a> |
| * @see <a href="http://www.w3.org/TR/xquery-semantics/#sec_fnerror">XQuery 1.0 and XPath 2.0 |
| * Formal Semantics, 7.2.9 The fn:error function</a> |
| * @author Frans Englich <frans.englich@nokia.com> |
| */ |
| class NoneType : public ItemType, |
| public SequenceType |
| { |
| public: |
| typedef QExplicitlySharedDataPointer<NoneType> Ptr; |
| |
| virtual bool itemMatches(const Item &item) const; |
| virtual bool xdtTypeMatches(const ItemType::Ptr &other) const; |
| |
| /** |
| * @returns always "none". That is, no namespace prefix |
| */ |
| virtual QString displayName(const NamePool::Ptr &np) const; |
| |
| /** |
| * @note The semantical meaning of this type's item type can |
| * surely be discussed. The function is provided due to |
| * it being mandated by the SequenceType base class. |
| * |
| * @returns always 'this' since NoneType is also an ItemType |
| */ |
| virtual ItemType::Ptr itemType() const; |
| |
| /** |
| * @note The semantical meaning of this type's cardinality |
| * can surely be discussed. The function is provided due to |
| * it being mandated by the SequenceType base class. |
| * |
| * @returns always Cardinality::zeroOrMore() |
| */ |
| virtual Cardinality cardinality() const; |
| |
| /** |
| * @returns always @c false |
| */ |
| virtual bool isAtomicType() const; |
| |
| /** |
| * This can be thought to be a weird function for this type(none). There |
| * is no atomized type for none, perhaps the best from a conceptual perspective |
| * would be to return @c null. |
| * |
| * This function returns BuiltinTypes::xsAnyAtomicType because |
| * the generic type checking code inserts an Atomizer in the AST |
| * when an error() function(or other node which has type none) is part of |
| * an operator expression(value/general comparison, arithmetics). The Atomizer |
| * returns the atomizedType() of its child, and by here returning xsAnyAtomicType, |
| * static operator lookup is postponed to runtime. Subsequently, expressions like error() |
| * works properly with other XPath expressions. |
| */ |
| virtual ItemType::Ptr atomizedType() const; |
| |
| /** |
| * @returns always @c false |
| */ |
| virtual bool isNodeType() const; |
| |
| /** |
| * @returns always item() |
| */ |
| virtual ItemType::Ptr xdtSuperType() const; |
| |
| /** |
| * @returns always @p other. The none type can be thought as |
| * disappearing when attempting to find the union of it and |
| * another type. |
| */ |
| virtual const ItemType &operator|(const ItemType &other) const; |
| |
| protected: |
| |
| friend class CommonSequenceTypes; |
| NoneType(); |
| }; |
| } |
| |
| QT_END_NAMESPACE |
| |
| QT_END_HEADER |
| |
| #endif |