[carterschonwald]

Definitely agree the best approach is doing modelling that results in trustworthy / usable coverage checking. ESP since for constrained ranges of values where new type won’t play great with supporting pattern matching without some fancy pattern synonyms.

I have seen folks write code that’s like

type Name = String

rather than use a new type, and I think really new type is about having enforced abstraction over the representation of a datatype, to prevent silent corruptions from transparently equivalent representations that have different meanings.

I guess I think it’s good to try to split this sort of opinion piece into a part that’s a forward looking tech challenge along side an exposition that hopefully has clear methodological guidance for today