src/xmlpatterns/iterators/qsubsequenceiterator_p.h
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/iterators/qsubsequenceiterator_p.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,118 @@
+/****************************************************************************
+**
+** 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