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/****************************************************************************
**
** Copyright (C) 2009 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_SubsequenceIterator_H
#define Patternist_SubsequenceIterator_H
#include "qitem_p.h"
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
namespace QPatternist
{
/**
* @short Picks out a slice from another QAbstractXmlForwardIterator, specified by a start and end position.
*
* SubsequenceIterator allows a "slice", a subsequence, from an QAbstractXmlForwardIterator to
* be extracted. The SubsequenceIterator's constructor takes a source QAbstractXmlForwardIterator,
* a start position, and the length of the subsequence to be extracted.
*
* SubsequenceIterator contains the central business logic to implement
* the <tt>fn:subsequence()</tt> function. The detailed behavior, such as how it behaves
* if the source QAbstractXmlForwardIterator is empty or if the specified subsequence stretches
* beyond the source QAbstractXmlForwardIterator, is therefore consistent with the definition of
* the <tt>fn:subsequence()</tt> function.
*
* @see <a href="http://www.w3.org/TR/xpath-functions/#func-subsequence">XQuery 1.0
* and XPath 2.0 Functions and Operators, 15.1.10 fn:subsequence</a>
* @author Frans Englich <frans.englich@nokia.com>
* @ingroup Patternist_iterators
*/
class SubsequenceIterator : public Item::Iterator
{
public:
/**
* Creates a SubsequenceIterator that extracts a subsequence from the sequence
* in @p iterator, as specified by the @p start position and @p length parameter.
*
* @param iterator the iterator which the subsequence should
* be extracted from
* @param start the start position of extraction. Must be 1 or larger.
* @param length the length of the subsequence to extract. If it is
* -1, to the end is returned. The value must be -1 or 1 or larger.
*/
SubsequenceIterator(const Item::Iterator::Ptr &iterator,
const xsInteger start,
const xsInteger length);
virtual Item next();
virtual Item current() const;
virtual xsInteger position() const;
virtual Item::Iterator::Ptr copy() const;
private:
xsInteger m_position;
Item m_current;
const Item::Iterator::Ptr m_it;
xsInteger m_counter;
const xsInteger m_start;
const xsInteger m_len;
const xsInteger m_stop;
};
}
QT_END_NAMESPACE
QT_END_HEADER
#endif
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