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Diffstat (limited to 'src/xmlpatterns/type/qnonetype_p.h')
-rw-r--r-- | src/xmlpatterns/type/qnonetype_p.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/xmlpatterns/type/qnonetype_p.h b/src/xmlpatterns/type/qnonetype_p.h new file mode 100644 index 0000000..f68d27d --- /dev/null +++ b/src/xmlpatterns/type/qnonetype_p.h @@ -0,0 +1,155 @@ +/**************************************************************************** +** +** 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. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, 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. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +// +// 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 |