diff options
Diffstat (limited to 'src/xmlpatterns/expr/qcastas_p.h')
| -rw-r--r-- | src/xmlpatterns/expr/qcastas_p.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qcastas_p.h b/src/xmlpatterns/expr/qcastas_p.h new file mode 100644 index 0000000..892b064 --- /dev/null +++ b/src/xmlpatterns/expr/qcastas_p.h @@ -0,0 +1,148 @@ +/**************************************************************************** +** +** 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_CastAs_H +#define Patternist_CastAs_H + +#include "qsinglecontainer_p.h" +#include "qcastingplatform_p.h" + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +namespace QPatternist +{ + /** + * @short Implements XPath 2.0's <tt>cast as</tt> expression. + * + * Implements the casting expression, such as <tt>'3' cast as xs:integer</tt>. This class also + * implements constructor functions, which are created in the ConstructorFunctionsFactory. + * + * CastAs uses CastingPlatform for carrying out the actual casting. + * + * @see <a href="http://www.w3.org/TR/xpath-functions/#casting">XQuery 1.0 + * and XPath 2.0 Functions and Operators, 7 Casting</a> + * @see <a href="http://www.w3.org/TR/xpath20/#id-cast">XML Path Language + * (XPath) 2.0, 3.10.2 Cast</a> + * @author Frans Englich <frans.englich@nokia.com> + * @ingroup Patternist_expressions + */ + class CastAs : public SingleContainer, + public CastingPlatform<CastAs, true /* issueError */> + { + public: + + /** + * @todo Wrong/old documentation + * + * Creates a cast expression for the type @p name via the schema type + * factory @p factory. This function is used by parser when creating + * 'cast to' expressions, and the ConstructorFunctionsFactory, when creating + * constructor functions. + * + * @param targetType the type which the CastAs should cast to + * @param source the operand to evaluate and then cast from + */ + CastAs(const Expression::Ptr &source, + const SequenceType::Ptr &targetType); + + virtual Item evaluateSingleton(const DynamicContext::Ptr &) const; + + virtual SequenceType::List expectedOperandTypes() const; + + /** + * @returns a SequenceType where the ItemType is this CastAs's + * target type, as per targetType(), and the Cardinality is inferred from the + * source operand to reflect whether this CastAs always will evaluate to + * exactly-one or zero-or-one values. + */ + virtual SequenceType::Ptr staticType() const; + + /** + * Overridden in order to check that casting to an abstract type + * is not attempted. + */ + virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context, + const SequenceType::Ptr &reqType); + + /** + * If the target type is the same as the source type, it is rewritten + * to the operand. + */ + virtual Expression::Ptr compress(const StaticContext::Ptr &context); + virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const; + + inline ItemType::Ptr targetType() const + { + return m_targetType->itemType(); + } + + inline SequenceType::Ptr targetSequenceType() const + { + return m_targetType; + } + + private: + /** + * Performs casting to @c xs:QName. This case is special, and is always done at compile time. + */ + Expression::Ptr castToQName(const StaticContext::Ptr &context) const; + + const SequenceType::Ptr m_targetType; + }; +} + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif |