qemptysequence.cpp

Go to the documentation of this file.

/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** 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, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qcommonvalues_p.h"
#include "qcommonsequencetypes_p.h"
#include "qemptysequencetype_p.h"

#include "qemptysequence_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

Expression::Ptr EmptySequence::create(const Expression *const replacementFor,
                                      const StaticContext::Ptr &context)
{
    Q_ASSERT(replacementFor);
    Q_ASSERT(context);

    const Expression::Ptr retval(new EmptySequence());
    context->wrapExpressionWith(replacementFor, retval);
    return retval;
}

Item::Iterator::Ptr EmptySequence::evaluateSequence(const DynamicContext::Ptr &) const
{
    return CommonValues::emptyIterator;
}

Item EmptySequence::evaluateSingleton(const DynamicContext::Ptr &) const
{
    return Item();
}

void EmptySequence::evaluateToSequenceReceiver(const DynamicContext::Ptr &) const
{
}

ItemType::Ptr EmptySequence::type() const
{
    return CommonSequenceTypes::Empty;
}

SequenceType::Ptr EmptySequence::staticType() const
{
    return CommonSequenceTypes::Empty;
}

bool EmptySequence::evaluateEBV(const DynamicContext::Ptr &) const
{
    return false;
}

QString EmptySequence::stringValue() const
{
    return QString();
}

ExpressionVisitorResult::Ptr EmptySequence::accept(const ExpressionVisitor::Ptr &visitor) const
{
    return visitor->visit(this);
}

Expression::ID EmptySequence::id() const
{
    return IDEmptySequence;
}

Expression::Properties EmptySequence::properties() const
{
    return IsEvaluated;
}

QT_END_NAMESPACE