Item GenericPredicate::mapToItem(const Item &item,
const DynamicContext::Ptr &context) const
{
const Item::Iterator::Ptr it(m_operand2->evaluateSequence(context));
const Item pcateItem(it->next());
if(!pcateItem)
return Item(); /* The predicate evaluated to the empty sequence */
else if(pcateItem.isNode())
return item;
/* Ok, now it must be an AtomicValue */
else if(BuiltinTypes::numeric->xdtTypeMatches(pcateItem.type()))
{ /* It's a positional predicate. */
if(it->next())
{
context->error(QtXmlPatterns::tr("A positional predicate must "
"evaluate to a single numeric "
"value."),
ReportContext::FORG0006, this);
return Item();
}
if(Double::isEqual(static_cast<xsDouble>(context->contextPosition()),
pcateItem.as<Numeric>()->toDouble()))
{
return item;
}
else
return Item();
}
else if(Boolean::evaluateEBV(pcateItem, it, context)) /* It's a truth predicate. */
return item;
else
return Item();
}
Item PositionFN::evaluateSingleton(const DynamicContext::Ptr &context) const
{
Q_ASSERT(context);
return Integer::fromValue(context->contextPosition());
}