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#include "qcommonsequencetypes_p.h"

#include "qexpressionsequence_p.h"

#include "qsorttuple_p.h"

#include "qreturnorderby_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

ReturnOrderBy::ReturnOrderBy(const OrderBy::Stability aStability,

                             const OrderBy::OrderSpec::Vector &oSpecs,

                             const Expression::List &ops) : UnlimitedContainer(ops)

                                                          , m_stability(aStability)

                                                          , m_orderSpecs(oSpecs)

                                                          , m_flyAway(true)

{

    Q_ASSERT_X(m_operands.size() >= 2, Q_FUNC_INFO,

               "ReturnOrderBy must have the return expression, and at least one sort key.");

    Q_ASSERT(m_orderSpecs.size() == ops.size() - 1);

}

Item ReturnOrderBy::evaluateSingleton(const DynamicContext::Ptr &context) const

{

    Q_ASSERT(m_operands.size() > 1);

    const Item::Iterator::Ptr value(makeListIterator(m_operands.first()->evaluateSequence(context)->toList()));

    Item::Vector sortKeys;

    /* We're skipping the first operand. */

    const int len = m_operands.size() - 1;

    sortKeys.resize(len);

    for(int i = 1; i <= len; ++i)

        sortKeys[i - 1] = m_operands.at(i)->evaluateSingleton(context);

    return Item(new SortTuple(value, sortKeys));

}

bool ReturnOrderBy::evaluateEBV(const DynamicContext::Ptr &context) const

{

    // TODO This is temporary code.

    return m_operands.first()->evaluateEBV(context);

}

Expression::Ptr ReturnOrderBy::compress(const StaticContext::Ptr &context)

{

    /* We first did this in typeCheck(), but that broke due to that type checks were

     * missed, which other pieces relied on. */

    if(m_flyAway)

    {

        /* We only want the return expression, not the sort keys. */

        return m_operands.first()->compress(context);

    }

    else

    {

        /* We don't need the members, so don't keep a reference to them. */

        m_orderSpecs.clear();

        return UnlimitedContainer::compress(context);

    }

}

Expression::Properties ReturnOrderBy::properties() const

{

    /* For some unknown reason this is necessary for XQTS test case orderBy18. */

    return DisableElimination;

}

ExpressionVisitorResult::Ptr ReturnOrderBy::accept(const ExpressionVisitor::Ptr &visitor) const

{

    return visitor->visit(this);

}

SequenceType::Ptr ReturnOrderBy::staticType() const

{

    return m_operands.first()->staticType();

}

SequenceType::List ReturnOrderBy::expectedOperandTypes() const

{

    SequenceType::List result;

    result.append(CommonSequenceTypes::ZeroOrMoreItems);

    result.append(CommonSequenceTypes::ZeroOrOneAtomicType);

    return result;

}

Expression::ID ReturnOrderBy::id() const

{

    return IDReturnOrderBy;

}

QT_END_NAMESPACE