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Diffstat (limited to 'src/xmlpatterns/expr/qtruthpredicate_p.h')
-rw-r--r-- | src/xmlpatterns/expr/qtruthpredicate_p.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qtruthpredicate_p.h b/src/xmlpatterns/expr/qtruthpredicate_p.h new file mode 100644 index 0000000..1a395bd --- /dev/null +++ b/src/xmlpatterns/expr/qtruthpredicate_p.h @@ -0,0 +1,112 @@ +/**************************************************************************** +** +** 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_TruthPredicate_H +#define Patternist_TruthPredicate_H + +#include "qgenericpredicate_p.h" + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +namespace QPatternist +{ + /** + * @short A predicate which is optimized for filter expressions that + * are of type @c xs:boolean. + * + * @author Frans Englich <frans.englich@nokia.com> + * @ingroup Patternist_expressions + */ + class TruthPredicate : public GenericPredicate + { + public: + /** + * Creates a TruthPredicate which filters the items from the @p sourceExpression + * through @p predicate. + * + * This constructor is protected. The proper way to create predicates is via the static + * create() function. + */ + TruthPredicate(const Expression::Ptr &sourceExpression, + const Expression::Ptr &predicate); + + inline Item mapToItem(const Item &item, const DynamicContext::Ptr &context) const + { + Q_ASSERT_X(false, Q_FUNC_INFO, "This is practically dead code because it never gets called in GenericPredicate, " + "which binds to its own mapToItem for completely legitime reasons."); + if(m_operand2->evaluateEBV(context)) + return item; + else + return Item(); + } + + inline Item::Iterator::Ptr map(const Item &item, + const DynamicContext::Ptr &context) const + { + Q_ASSERT_X(false, Q_FUNC_INFO, "I don't expect this function to be called, for the same reasons as above."); + if(m_operand2->evaluateEBV(context)) + return makeSingletonIterator(item); + else + return CommonValues::emptyIterator; + } + + virtual SequenceType::List expectedOperandTypes() const; + virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const; + }; +} + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif |