--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qoperandsiterator_p.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,193 @@
+/****************************************************************************
+**
+** 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_OperandsIterator_H
+#define Patternist_OperandsIterator_H
+
+#include <QPair>
+#include <QStack>
+
+#include "qexpression_p.h"
+
+QT_BEGIN_HEADER
+
+QT_BEGIN_NAMESPACE
+
+namespace QPatternist
+{
+    /**
+     * @short A helper class that iterates a tree of Expression instances. It
+     * is not a sub-class of QAbstractXmlForwardIterator.
+     *
+     * The OperandsIterator delivers all Expression instances that are children at any
+     * depth of the Expression passed in the constructor.
+     * The order is delivered in a defined way, from left to right and depth
+     * first.
+     *
+     * @author Frans Englich <frans.englich@nokia.com>
+     */
+    class OperandsIterator
+    {
+        /**
+         * The second value, the int, is the current position in the first.
+         */
+        typedef QPair<Expression::List, int> Level;
+
+    public:
+        enum TreatParent
+        {
+            ExcludeParent,
+            IncludeParent
+        };
+
+        /**
+         * if @p treatParent is @c IncludeParent, @p start is excluded.
+         *
+         * @p start must be a valid Expression.
+         */
+        inline OperandsIterator(const Expression::Ptr &start,
+                                const TreatParent treatParent)
+        {
+            Q_ASSERT(start);
+            if(treatParent == IncludeParent)
+            {
+                Expression::List l;
+                l.append(start);
+                m_exprs.push(qMakePair(l, -1));
+            }
+
+            m_exprs.push(qMakePair(start->operands(), -1));
+        }
+
+        /**
+         * @short Returns the current Expression and advances the iterator.
+         *
+         * If the end has been reached, a default constructed pointer is
+         * returned.
+         *
+         * We intentionally return by reference.
+         */
+        inline Expression::Ptr next()
+        {
+            if(m_exprs.isEmpty())
+                return Expression::Ptr();
+
+            Level &lvl = m_exprs.top();
+            ++lvl.second;
+
+            if(lvl.second == lvl.first.size())
+            {
+                /* Resume iteration above us. */
+                m_exprs.pop();
+
+                if(m_exprs.isEmpty())
+                    return Expression::Ptr();
+
+                while(true)
+                {
+                    Level &previous = m_exprs.top();
+                    ++previous.second;
+
+                    if(previous.second < previous.first.count())
+                    {
+                        const Expression::Ptr &op = previous.first.at(previous.second);
+                        m_exprs.push(qMakePair(op->operands(), -1));
+                        return op;
+                    }
+                    else
+                    {
+                        // We have already reached the end of this level.
+                        m_exprs.pop();
+                        if(m_exprs.isEmpty())
+                            return Expression::Ptr();
+                    }
+                }
+            }
+            else
+            {
+                const Expression::Ptr &op = lvl.first.at(lvl.second);
+                m_exprs.push(qMakePair(op->operands(), -1));
+                return op;
+            }
+        }
+
+        /**
+         * Advances this iterator by the current expression and its operands.
+         */
+        Expression::Ptr skipOperands()
+        {
+            if(m_exprs.isEmpty())
+                return Expression::Ptr();
+
+            Level &lvl = m_exprs.top();
+            ++lvl.second;
+
+            if(lvl.second == lvl.first.size())
+            {
+                /* We've reached the end of this level, at least. */
+                m_exprs.pop();
+            }
+
+            return next();
+        }
+
+    private:
+        Q_DISABLE_COPY(OperandsIterator)
+
+        QStack<Level> m_exprs;
+    };
+}
+
+
+QT_END_NAMESPACE
+QT_END_HEADER
+
+#endif