/**************************************************************************** | |
** | |
** 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. | |
** | |
** | |
** | |
** | |
** | |
** $QT_END_LICENSE$ | |
** | |
****************************************************************************/ | |
// | |
// 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_DistinctIterator_H | |
#define Patternist_DistinctIterator_H | |
#include <QList> | |
#include "qexpression_p.h" | |
#include "qitem_p.h" | |
#include "qatomiccomparator_p.h" | |
#include "qcomparisonplatform_p.h" | |
#include "qsourcelocationreflection_p.h" | |
QT_BEGIN_HEADER | |
QT_BEGIN_NAMESPACE | |
namespace QPatternist | |
{ | |
/** | |
* @short Filters another sequence by removing duplicates such that the items are unique. | |
* | |
* DistinctIterator takes an input sequence, and returns a sequence where each | |
* item is unique. Thus, DistinctIterator removes the duplicates of items | |
* in a sequence. DistinctIterator is central in the implementation of the | |
* <tt>fn:distinct-values()</tt> function. | |
* | |
* @see <a href="http://www.w3.org/TR/xpath-functions/#func-distinct-values">XQuery 1.0 | |
* and XPath 2.0 Functions and Operators, 15.1.6 fn:distinct-values</a> | |
* @author Frans Englich <frans.englich@nokia.com> | |
* @ingroup Patternist_iterators | |
*/ | |
class DistinctIterator : public Item::Iterator | |
, public ComparisonPlatform<DistinctIterator, false> | |
, public SourceLocationReflection | |
{ | |
public: | |
/** | |
* Creates a DistinctIterator. | |
* @param comp the AtomicComparator to be used for comparing values. This may be @c null, | |
* meaning the IndexOfIterator iterator will dynamically determine what comparator to use | |
* @param seq the sequence whose duplicates should be filtered out | |
* @param context the usual context, used for error reporting and by AtomicComparators. | |
* @param expression the Expression that this DistinctIterator is | |
* evaluating for. It is used for error reporting, via | |
* actualReflection(). | |
*/ | |
DistinctIterator(const Item::Iterator::Ptr &seq, | |
const AtomicComparator::Ptr &comp, | |
const Expression::ConstPtr &expression, | |
const DynamicContext::Ptr &context); | |
virtual Item next(); | |
virtual Item current() const; | |
virtual xsInteger position() const; | |
virtual Item::Iterator::Ptr copy() const; | |
virtual const SourceLocationReflection *actualReflection() const; | |
inline AtomicComparator::Operator operatorID() const | |
{ | |
return AtomicComparator::OperatorEqual; | |
} | |
private: | |
const Item::Iterator::Ptr m_seq; | |
const DynamicContext::Ptr m_context; | |
const Expression::ConstPtr m_expr; | |
Item m_current; | |
xsInteger m_position; | |
Item::List m_processed; | |
}; | |
} | |
QT_END_NAMESPACE | |
QT_END_HEADER | |
#endif |