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#include "qatomictype_p.h"
#include "qbuiltintypes_p.h"
#include "qcommonsequencetypes_p.h"
#include "qgenericsequencetype_p.h"
#include "qsequencemappingiterator_p.h"

#include "qatomizer_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

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

Item::Iterator::Ptr Atomizer::mapToSequence(const Item &item, const DynamicContext::Ptr &) const
{
    /* Function & Operators, 2.4.2 fn:data, says "If the node does not have a
     * typed value an error is raised [err:FOTY0012]."
     * When does a node not have a typed value? */
    Q_ASSERT(item);
    return item.sequencedTypedValue();
}

Item::Iterator::Ptr Atomizer::evaluateSequence(const DynamicContext::Ptr &context) const
{
    return makeSequenceMappingIterator<Item>(ConstPtr(this),
                                             m_operand->evaluateSequence(context),
                                             context);
}

Item Atomizer::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    const Item item(m_operand->evaluateSingleton(context));

    if(!item) /* Empty is allowed, cardinality is considered '?' */
        return Item();

    const Item::Iterator::Ptr it(mapToSequence(item, context));
    Q_ASSERT_X(it, Q_FUNC_INFO, "A valid QAbstractXmlForwardIterator must always be returned.");

    Item result(it->next());
    Q_ASSERT_X(!it->next(), Q_FUNC_INFO,
               "evaluateSingleton should never be used if the cardinality is two or more");

    return result;
}

Expression::Ptr Atomizer::typeCheck(const StaticContext::Ptr &context,
                                    const SequenceType::Ptr &reqType)
{
    /* Compress -- the earlier the better. */
    if(BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(m_operand->staticType()->itemType()))
        return m_operand->typeCheck(context, reqType);

    return SingleContainer::typeCheck(context, reqType);
}

SequenceType::Ptr Atomizer::staticType() const
{
    const SequenceType::Ptr opt(m_operand->staticType());
    return makeGenericSequenceType(opt->itemType()->atomizedType(),
                                   opt->cardinality());
}

SequenceType::List Atomizer::expectedOperandTypes() const
{
    SequenceType::List result;
    result.append(CommonSequenceTypes::ZeroOrMoreItems);
    return result;
}

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

const SourceLocationReflection *Atomizer::actualReflection() const
{
    return m_operand->actualReflection();
}

QT_END_NAMESPACE
