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#include "qcommonsequencetypes_p.h"
#include "qatomicstring_p.h"

#include "qsimplecontentconstructor_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

SimpleContentConstructor::SimpleContentConstructor(const Expression::Ptr &operand) : SingleContainer(operand)
{
}

Item SimpleContentConstructor::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));
    Item next(it->next());
    QString result;

    if(next)
    {
        result = next.stringValue();
        next = it->next();
    }
    else
        return Item();

    while(next)
    {
        result += QLatin1Char(' ');
        result += next.stringValue();
        next = it->next();
    }

    return AtomicString::fromValue(result);
}

Expression::Ptr SimpleContentConstructor::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr me(SingleContainer::compress(context));

    if(me.data() == this)
    {
        /* Optimization: if we will evaluate to a single string, we're not
         * necessary. */
        if(CommonSequenceTypes::ExactlyOneString->matches(m_operand->staticType()))
            return m_operand;
    }

    return me;
}

SequenceType::List SimpleContentConstructor::expectedOperandTypes() const
{
    SequenceType::List result;
    result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
    return result;
}

SequenceType::Ptr SimpleContentConstructor::staticType() const
{
    if(m_operand->staticType()->cardinality().allowsEmpty())
        return CommonSequenceTypes::ZeroOrOneString;
    else
        return CommonSequenceTypes::ExactlyOneString;
}

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

QT_END_NAMESPACE
