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Diffstat (limited to 'src/xmlpatterns/expr/qgenericpredicate_p.h')
| -rw-r--r-- | src/xmlpatterns/expr/qgenericpredicate_p.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qgenericpredicate_p.h b/src/xmlpatterns/expr/qgenericpredicate_p.h new file mode 100644 index 0000000..fe0eda6 --- /dev/null +++ b/src/xmlpatterns/expr/qgenericpredicate_p.h @@ -0,0 +1,148 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, 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. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@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_GenericPredicate_H +#define Patternist_GenericPredicate_H + +#include "qpaircontainer_p.h" + +QT_BEGIN_HEADER + +QT_BEGIN_NAMESPACE + +namespace QPatternist +{ + /** + * @short A predicate that can handle all kinds of predicates and + * is therefore not very efficient, but can cope with all the tricky scenarios. + * + * @see FirstItemPredicate + * @see TruthPredicate + * @author Frans Englich <fenglich@trolltech.com> + * @ingroup Patternist_expressions + */ + class GenericPredicate : public PairContainer + { + public: + + /** + * Creates a predicate expression that filters the items gained + * from evaluating @p sourceExpression through the filter @p predicateExpression. + * + * This function performs type analyzis on the passed expressions, and may + * return more specialized expressions depending on the analyzis. + * + * If @p predicateExpression is an invalid predicate, an error is issued + * via the @p context. + */ + static Expression::Ptr create(const Expression::Ptr &sourceExpression, + const Expression::Ptr &predicateExpression, + const StaticContext::Ptr &context, + const QSourceLocation &location); + + static Expression::Ptr createFirstItem(const Expression::Ptr &sourceExpression); + + /** + * Creates a source iterator which is passed to the ItemMappingIterator + * and the Focus. The ItemMappingIterator modifies it with + * its QAbstractXmlForwardIterator::next() calls, and since the Focus references the same QAbstractXmlForwardIterator, + * the focus is automatically moved. + */ + virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const; + + /** + * Doesn't return the first item from calling evaluateSequence(), but does the mapping + * manually. This avoid allocating an ItemMappingIterator. + */ + virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const; + + inline Item mapToItem(const Item &subject, + const DynamicContext::Ptr &) const; + + virtual SequenceType::List expectedOperandTypes() const; + virtual SequenceType::Ptr staticType() const; + virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const; + virtual ID id() const; + + /** + * @returns always CreatesFocusForLast. + */ + virtual Properties properties() const; + + virtual QString description() const; + + protected: + + /** + * Creates a GenericPredicate 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. + */ + GenericPredicate(const Expression::Ptr &sourceExpression, + const Expression::Ptr &predicate); + + /** + * @returns the ItemType of the first operand's staticType(). + */ + virtual ItemType::Ptr newFocusType() const; + + private: + typedef QExplicitlySharedDataPointer<const GenericPredicate> ConstPtr; + }; +} + +QT_END_NAMESPACE + +QT_END_HEADER + +#endif |