--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qnodecomparison.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,184 @@
+/****************************************************************************
+**
+** 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 "qcommonvalues_p.h"
+#include "qemptysequence_p.h"
+#include "qinteger_p.h"
+#include "qschemanumeric_p.h"
+#include "qrangeiterator_p.h"
+
+#include "qnodecomparison_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+NodeComparison::NodeComparison(const Expression::Ptr &operand1,
+                               const QXmlNodeModelIndex::DocumentOrder op,
+                               const Expression::Ptr &operand2)
+                               : PairContainer(operand1, operand2)
+                               , m_op(op)
+{
+    Q_ASSERT(op == QXmlNodeModelIndex::Precedes   ||
+             op == QXmlNodeModelIndex::Follows    ||
+             op == QXmlNodeModelIndex::Is);
+}
+
+Item NodeComparison::evaluateSingleton(const DynamicContext::Ptr &context) const
+{
+    switch(evaluate(context))
+    {
+        case True:
+            return CommonValues::BooleanTrue;
+        case False:
+            return CommonValues::BooleanFalse;
+        default:
+            return Item();
+    }
+}
+
+bool NodeComparison::evaluateEBV(const DynamicContext::Ptr &context) const
+{
+    switch(evaluate(context))
+    {
+        case True:
+            return true;
+        default:
+            /* We include the empty sequence here. */
+            return false;
+    }
+}
+
+NodeComparison::Result NodeComparison::evaluate(const DynamicContext::Ptr &context) const
+{
+    const Item op1(m_operand1->evaluateSingleton(context));
+    if(!op1)
+        return Empty;
+
+    const Item op2(m_operand2->evaluateSingleton(context));
+    if(!op2)
+        return Empty;
+
+    /* We just returns an arbitrary value, since there's no order defined for nodes from different
+     * models, except for that the return value must be stable. */
+    if(op1.asNode().model() != op2.asNode().model())
+        return False;
+
+    switch(m_op)
+    {
+        case QXmlNodeModelIndex::Is:
+            return op1.asNode().is(op2.asNode()) ? True : False;
+        case QXmlNodeModelIndex::Precedes:
+            return op1.asNode().compareOrder(op2.asNode()) == QXmlNodeModelIndex::Precedes ? True : False;
+        default:
+        {
+            Q_ASSERT(m_op == QXmlNodeModelIndex::Follows);
+            return op1.asNode().compareOrder(op2.asNode()) == QXmlNodeModelIndex::Follows ? True : False;
+        }
+    }
+}
+
+
+SequenceType::List NodeComparison::expectedOperandTypes() const
+{
+    SequenceType::List result;
+    result.append(CommonSequenceTypes::ZeroOrOneNode);
+    result.append(CommonSequenceTypes::ZeroOrOneNode);
+    return result;
+}
+
+Expression::Ptr NodeComparison::compress(const StaticContext::Ptr &context)
+{
+    const Expression::Ptr me(PairContainer::compress(context));
+
+    if(me != this)
+    /* We're already rewritten. */
+        return me;
+
+    if(m_operand1->staticType()->cardinality().isEmpty() ||
+       m_operand2->staticType()->cardinality().isEmpty())
+    {
+        // TODO issue a warning in the @p context saying that one of the operands
+        // were empty, and that the expression always result in the empty sequence
+        // (which never is the intent, right?).
+        return EmptySequence::create(this, context);
+    }
+
+    return Expression::Ptr(this);
+}
+
+QString NodeComparison::displayName(const QXmlNodeModelIndex::DocumentOrder op)
+{
+    switch(op)
+    {
+        case QXmlNodeModelIndex::Is:
+            return QLatin1String("is");
+        case QXmlNodeModelIndex::Precedes:
+            return QLatin1String("<<");
+        default:
+        {
+            Q_ASSERT(op == QXmlNodeModelIndex::Follows);
+            return QLatin1String(">>");
+        }
+    }
+}
+
+SequenceType::Ptr NodeComparison::staticType() const
+{
+    if(m_operand1->staticType()->cardinality().allowsEmpty() ||
+       m_operand2->staticType()->cardinality().allowsEmpty())
+        return CommonSequenceTypes::ZeroOrOneBoolean;
+    else
+        return CommonSequenceTypes::ExactlyOneBoolean;
+}
+
+QXmlNodeModelIndex::DocumentOrder NodeComparison::operatorID() const
+{
+    return m_op;
+}
+
+ExpressionVisitorResult::Ptr NodeComparison::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+    return visitor->visit(this);
+}
+
+QT_END_NAMESPACE