SequenceType::Ptr RemoveFN::staticType() const
{
const SequenceType::Ptr opType(m_operands.first()->staticType());
const Cardinality c(opType->cardinality());
if(c.minimum() == 0)
return makeGenericSequenceType(opType->itemType(), c);
else
{
return makeGenericSequenceType(opType->itemType(),
Cardinality::fromRange(c.minimum() - 1,
c.maximum()));
}
}
Expression::Ptr CountFN::compress(const StaticContext::Ptr &context)
{
const Expression::Ptr me(FunctionCall::compress(context));
if(me != this)
return me;
const Cardinality card(m_operands.first()->staticType()->cardinality());
if(card.isExactlyOne())
return wrapLiteral(CommonValues::IntegerOne, context, this);
else if(card.isEmpty())
{
/* One might think that if the operand is (), that compress() would have
* evaluated us and therefore this line never be reached, but "()" can
* be combined with the DisableElimination flag. */
return wrapLiteral(CommonValues::IntegerZero, context, this);
}
else if(card.isExact())
return wrapLiteral(Integer::fromValue(card.minimum()), context, this);
else
return me;
}