src/xmlpatterns/expr/qcopyof.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/expr/qcopyof.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,134 @@
+/****************************************************************************
+**
+** 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 "qbuiltintypes_p.h"
+#include "qcommonsequencetypes_p.h"
+#include "qitemmappingiterator_p.h"
+
+#include "qcopyof_p.h"
+
+QT_BEGIN_NAMESPACE
+
+using namespace QPatternist;
+
+CopyOf::CopyOf(const Expression::Ptr &operand,
+               const bool inheritNSS,
+               const bool preserveNSS) : SingleContainer(operand)
+                                       , m_inheritNamespaces(inheritNSS)
+                                       , m_preserveNamespaces(preserveNSS)
+                                       , m_settings((m_inheritNamespaces ? QAbstractXmlNodeModel::InheritNamespaces : QAbstractXmlNodeModel::NodeCopySettings()) |
+                                                    (m_preserveNamespaces ? QAbstractXmlNodeModel::PreserveNamespaces : QAbstractXmlNodeModel::NodeCopySettings()))
+{
+}
+
+Expression::Ptr CopyOf::compress(const StaticContext::Ptr &context)
+{
+    /* We have zero effect if we have these settings. */
+    if(m_inheritNamespaces && m_preserveNamespaces)
+        return m_operand->compress(context);
+    else
+    {
+        const ItemType::Ptr t(m_operand->staticType()->itemType());
+        /* We have no effect on the empty sequence or atomic values. */
+        if(BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(t)
+          || *t == *CommonSequenceTypes::Empty)
+            return m_operand->compress(context);
+        else
+            return SingleContainer::compress(context);
+    }
+}
+
+void CopyOf::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
+{
+    /* Optimization: this completely breaks streaming. We get a call to
+     * evaluateToSequenceReceiver() but we require heap allocations by calling
+     * evaluateSequence(). */
+
+    const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));
+    QAbstractXmlReceiver *const receiver = context->outputReceiver();
+    Item next(it->next());
+
+    while(next)
+    {
+        if(next.isNode())
+        {
+            const QXmlNodeModelIndex &asNode = next.asNode();
+            asNode.model()->copyNodeTo(asNode, receiver, m_settings);
+        }
+        else
+            receiver->item(next);
+
+        next = it->next();
+    }
+}
+
+ExpressionVisitorResult::Ptr CopyOf::accept(const ExpressionVisitor::Ptr &visitor) const
+{
+    return visitor->visit(this);
+}
+
+SequenceType::Ptr CopyOf::staticType() const
+{
+    return m_operand->staticType();
+}
+
+SequenceType::List CopyOf::expectedOperandTypes() const
+{
+    SequenceType::List result;
+    result.append(CommonSequenceTypes::ZeroOrMoreItems);
+    return result;
+}
+
+Expression::Properties CopyOf::properties() const
+{
+    /* We have the content of node constructors as children, but even though
+     * createCopyOf() typically avoids creating us, we can still end up with an operand
+     * that allows compression. We must always avoid that, because we don't have
+     * implementation of evaluateSequence(), and so on. */
+    return (m_operand->properties() & ~CreatesFocusForLast) | DisableElimination;
+}
+
+ItemType::Ptr CopyOf::expectedContextItemType() const
+{
+    return m_operand->expectedContextItemType();
+}
+
+QT_END_NAMESPACE