source: trunk/src/xmlpatterns/expr/qpath.cpp@ 843

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#include "qbuiltintypes_p.h"
#include "qcommonsequencetypes_p.h"
#include "qgenericsequencetype_p.h"
#include "qnodesort_p.h"
#include "qpatternistlocale_p.h"
#include "qsequencemappingiterator_p.h"
#include "qtypechecker_p.h"

#include "qpath_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

Path::Path(const Expression::Ptr &operand1,
           const Expression::Ptr &operand2,
           const Kind kind) : PairContainer(operand1, operand2)
                            , m_hasCreatedSorter(kind != RegularPath)
                            , m_isLast(false)
                            , m_checkXPTY0018(kind == RegularPath)
                            , m_kind(kind)
{
}

Item::Iterator::Ptr Path::mapToSequence(const Item &item,
                                        const DynamicContext::Ptr &context) const
{
    /* item is the focus here. That is in <e/>/1, item is <e/>. However,
     * we don't use it, since the context item is accessed through
     * DynamicContext::focusIterator() and friends. */
    Q_ASSERT(item);
    Q_UNUSED(item); /* Needed when compiling in release mode. */
    return m_operand2->evaluateSequence(context);
}

Item::Iterator::Ptr Path::evaluateSequence(const DynamicContext::Ptr &context) const
{
    /* Note, we use the old context for m_operand1. */
    const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));

    const DynamicContext::Ptr focus(context->createFocus());
    focus->setFocusIterator(source);

    const Item::Iterator::Ptr result(makeSequenceMappingIterator<Item>(ConstPtr(this), source, focus));

    if(m_checkXPTY0018)
    {
        /* This is an expensive code path, but it should happen very rarely. */

        enum FoundItem
        {
            FoundNone,
            FoundNode,
            FoundAtomicValue
        } hasFound = FoundNone;

        Item::List whenChecked;

        Item next(result->next());

        while(next)
        {
            const FoundItem found = next.isAtomicValue() ? FoundAtomicValue : FoundNode;

            if(hasFound != FoundNone && hasFound != found)
            {
                /* It's an atomic value and we've already found a node. Mixed content. */
                context->error(QtXmlPatterns::tr("The last step in a path must contain either nodes "
                                                 "or atomic values. It cannot be a mixture between the two."),
                               ReportContext::XPTY0018, this);
            }
            else
                hasFound = found;

            whenChecked.append(next);
            next = result->next();
        }