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** Copyright (C) 2016 The Qt Company Ltd.
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** This file is part of the QtXmlPatterns module of the Qt Toolkit.
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****************************************************************************/

#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