--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qcombinenodes.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,172 @@
+/****************************************************************************
+**
+** 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcommonsequencetypes_p.h"
+#include "qexceptiterator_p.h"
+#include "qgenericsequencetype_p.h"
+#include "qintersectiterator_p.h"
+#include "qitemmappingiterator_p.h"
+#include "qnodesort_p.h"
+#include "qunioniterator_p.h"
+
+#include "qcombinenodes_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+CombineNodes::CombineNodes(const Expression::Ptr &operand1,
+                           const Operator op,
+                           const Expression::Ptr &operand2) : PairContainer(operand1, operand2),
+                                                              m_operator(op)
+{
+    Q_ASSERT(op == Union    ||
+             op == Except   ||
+             op == Intersect);
+}
+
+Item::Iterator::Ptr CombineNodes::evaluateSequence(const DynamicContext::Ptr &context) const
+{
+    const Item::Iterator::Ptr op1(m_operand1->evaluateSequence(context));
+    const Item::Iterator::Ptr op2(m_operand2->evaluateSequence(context));
+
+    switch(m_operator)
+    {
+        case Intersect:
+            return Item::Iterator::Ptr(new IntersectIterator(op1, op2));
+        case Except:
+            return Item::Iterator::Ptr(new ExceptIterator(op1, op2));
+        default:
+        {
+            Q_ASSERT(m_operator == Union);
+            return Item::Iterator::Ptr(new UnionIterator(op1, op2));
+        }
+    }
+}
+
+Item CombineNodes::evaluateSingleton(const DynamicContext::Ptr &context) const
+{
+    return evaluateSequence(context)->next();
+}
+
+Expression::Ptr CombineNodes::typeCheck(const StaticContext::Ptr &context,
+                                        const SequenceType::Ptr &reqType)
+{
+
+    const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
+
+    m_operand1 = NodeSortExpression::wrapAround(m_operand1, context);
+    m_operand2 = NodeSortExpression::wrapAround(m_operand2, context);
+
+    return me;
+}
+
+bool CombineNodes::evaluateEBV(const DynamicContext::Ptr &context) const
+{
+    /* If it's the union operator, we can possibly avoid
+     * evaluating the second operand. */
+
+    if(m_operator == Union)
+    {
+        return m_operand1->evaluateEBV(context) ||
+               m_operand2->evaluateEBV(context);
+    }
+    else
+        return PairContainer::evaluateEBV(context);
+}
+
+QString CombineNodes::displayName(const Operator op)
+{
+    switch(op)
+    {
+        case Intersect:
+            return QLatin1String("intersect");
+        case Except:
+            return QLatin1String("except");
+        default:
+        {
+            Q_ASSERT(op == Union);
+            return QLatin1String("union");
+        }
+    }
+}
+
+SequenceType::Ptr CombineNodes::staticType() const
+{
+    const SequenceType::Ptr t1(m_operand1->staticType());
+    const SequenceType::Ptr t2(m_operand2->staticType());
+
+     Cardinality card;
+
+     /* Optimization: the cardinality can be better inferred for
+      * Intersect and Except, although it's not trivial code. */
+     if(m_operator == Union)
+         card = t1->cardinality() | t2->cardinality();
+     else /* Except. */
+         card = Cardinality::zeroOrMore();
+
+     return makeGenericSequenceType(t1->itemType() | t2->itemType(), card);
+}
+
+SequenceType::List CombineNodes::expectedOperandTypes() const
+{
+    SequenceType::List result;
+    result.append(CommonSequenceTypes::ZeroOrMoreNodes);
+    result.append(CommonSequenceTypes::ZeroOrMoreNodes);
+    return result;
+}
+
+CombineNodes::Operator CombineNodes::operatorID() const
+{
+    return m_operator;
+}
+
+ExpressionVisitorResult::Ptr CombineNodes::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+    return visitor->visit(this);
+}
+
+Expression::ID CombineNodes::id() const
+{
+    return IDCombineNodes;
+}
+
+QT_END_NAMESPACE