--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qcastableas.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,157 @@
+/****************************************************************************
+**
+** 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 "qatomictype_p.h"
+#include "qitem_p.h"
+#include "qboolean_p.h"
+#include "qbuiltintypes_p.h"
+#include "qcommonsequencetypes_p.h"
+#include "qcommonvalues_p.h"
+#include "qliteral_p.h"
+
+#include "qcastableas_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+CastableAs::CastableAs(const Expression::Ptr &operand,
+                       const SequenceType::Ptr &tType) : SingleContainer(operand),
+                                                         m_targetType(tType)
+{
+    Q_ASSERT(tType);
+    Q_ASSERT(!tType->cardinality().allowsMany());
+    Q_ASSERT(tType->itemType()->isAtomicType());
+}
+
+bool CastableAs::evaluateEBV(const DynamicContext::Ptr &context) const
+{
+    Item item;
+
+    if(m_operand->staticType()->cardinality().allowsMany())
+    {
+        const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));
+        item = it->next();
+
+        if(it->next())
+            return false;
+    }
+    else
+        item = m_operand->evaluateSingleton(context);
+
+    if(item)
+        return !cast(item, context).as<AtomicValue>()->hasError();
+    else
+        return m_targetType->cardinality().allowsEmpty();
+}
+
+Expression::Ptr CastableAs::compress(const StaticContext::Ptr &context)
+{
+    const Expression::Ptr me(SingleContainer::compress(context));
+
+    if(me != this) /* We already managed to const fold, how convenient. */
+        return me;
+
+    const AtomicType::Ptr t(m_targetType->itemType());
+
+    const SequenceType::Ptr opType(m_operand->staticType());
+
+    /* Casting to these always succeeds, assuming the cardinality also matches,
+     * although the cardinality can fail. */
+    if((   *t == *BuiltinTypes::xsString
+        || *t == *BuiltinTypes::xsUntypedAtomic
+        || *t == *opType->itemType())
+       &&(m_targetType->cardinality().isMatch(opType->cardinality())))
+    {
+        return wrapLiteral(CommonValues::BooleanTrue, context, this);
+    }
+    else
+        return me;
+}
+
+Expression::Ptr CastableAs::typeCheck(const StaticContext::Ptr &context,
+                                      const SequenceType::Ptr &reqType)
+{
+    checkTargetType(context);
+    const Expression::Ptr me(SingleContainer::typeCheck(context, reqType));
+
+    return me;
+    if(BuiltinTypes::xsQName->xdtTypeMatches(m_targetType->itemType()))
+    {
+        const SequenceType::Ptr seqt(m_operand->staticType());
+        /* We can cast a string literal, an xs:QName value, and an
+         * empty sequence(if empty is allowed), to xs:QName. */
+        if(m_operand->is(IDStringValue) ||
+           BuiltinTypes::xsQName->xdtTypeMatches(seqt->itemType()) ||
+           (*seqt->itemType() == *CommonSequenceTypes::Empty && m_targetType->cardinality().allowsEmpty()))
+        {
+            return wrapLiteral(CommonValues::BooleanTrue, context, this)->typeCheck(context, reqType);
+        }
+        else
+            return wrapLiteral(CommonValues::BooleanFalse, context, this)->typeCheck(context, reqType);
+    }
+    else
+    {
+        /* Let the CastingPlatform look up its AtomicCaster. */
+        prepareCasting(context, m_operand->staticType()->itemType());
+
+        return me;
+    }
+}
+
+SequenceType::List CastableAs::expectedOperandTypes() const
+{
+    SequenceType::List result;
+    result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
+    return result;
+}
+
+SequenceType::Ptr CastableAs::staticType() const
+{
+    return CommonSequenceTypes::ExactlyOneBoolean;
+}
+
+ExpressionVisitorResult::Ptr CastableAs::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+    return visitor->visit(this);
+}
+
+QT_END_NAMESPACE