Item::Iterator::Ptr CardinalityVerifier::evaluateSequence(const DynamicContext::Ptr &context) const
{
const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));
const Item next(it->next());
if(next)
{
const Item next2(it->next());
if(next2)
{
if(m_reqCard.allowsMany())
{
Item::List start;
start.append(next);
start.append(next2);
return Item::Iterator::Ptr(new InsertionIterator(it, 1, makeListIterator(start)));
}
else
{
context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()), m_errorCode, this);
return CommonValues::emptyIterator;
}
}
else
{
/* We might be instantiated for the empty sequence. */
if(m_reqCard.isEmpty())
{
context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()), m_errorCode, this);
return CommonValues::emptyIterator;
}
else
return makeSingletonIterator(next);
}
}
else
{
if(m_reqCard.allowsEmpty())
return CommonValues::emptyIterator;
else
{
context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()), m_errorCode, this);
return CommonValues::emptyIterator;
}
}
}
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();
}
return makeListIterator(whenChecked);
}
else
return result;
}
bool GeneralComparison::evaluateEBV(const DynamicContext::Ptr &context) const
{
const Item::Iterator::Ptr it1(m_operand1->evaluateSequence(context));
Item item1(it1->next());
if(!item1)
return false;
const Item::Iterator::Ptr it2(m_operand2->evaluateSequence(context));
Item::List cache;
Item item2;
while(true)
{
item2 = it2->next();
if(!item2)
break;
if(generalCompare(item1, item2, context))
return true;
cache.append(item2);
}
while(true)
{
item1 = it1->next();
if(!item1)
return false;
const Item::List::const_iterator end(cache.constEnd());
Item::List::const_iterator it(cache.constBegin());
for(; it != end; ++it)
if(generalCompare(item1, *it, context))
return true;
}
Q_ASSERT(false);
return false;
}
Expression::Ptr Expression::constantPropagate(const StaticContext::Ptr &context) const
{
Q_ASSERT(context);
/* Optimization: We rewrite literals to literals here, which is pointless.
* Maybe we should have a property which says "doesn't disable elimination
* but don't eliminate me." */
if(staticType()->cardinality().allowsMany())
{
Item::Iterator::Ptr it(evaluateSequence(context->dynamicContext()));
Item::List result;
Item item(it->next());
while(item)
{
result.append(item);
item = it->next();
}
switch(result.count())
{
case 0:
return EmptySequence::create(this, context);
case 1:
return rewrite(Expression::Ptr(new Literal(result.first())), context);
default:
return rewrite(Expression::Ptr(new LiteralSequence(result)), context);
}
}
else
{
const Item item(evaluateSingleton(context->dynamicContext()));
if(item)
return rewrite(Expression::Ptr(new Literal(item)), context);
else
return EmptySequence::create(this, context);
}
}
