- # XXX: this None could later be generalized into an empty list,
- # whose length is the constant 0; so let's tentatively answer 0.
- return immutablevalue(0)
+ # This None could later be generalized into a list, for example.
+ # For now, we give the impossible answer (because len(None) would
+ # really crash translated code). It can be generalized later.
+ return SomeImpossibleValue()