I'm not. Why should empty have Ord?
This Tweet is unavailable. Learn more
Conversation
I have issues with type classes as well but I share this concern with Brian - by parameterizing the entire data structure on a dictionary every method has that constraint, even those that don't need it (e.g. empty).
1
2
I still don't understand why its the end of the world. It's needed because the way you order the set is important for the semantics of the data structure. I'd be fine with the tradeoff.
From a different perspective, leaving off the 'Ord' from empty could be seen more as exploiting the hack that type classes build into the language - ie. global coherence. Not saying I necessarily agree - but I don't see it as clear cut.🤷♂️
1
IIUC, assuming you *only* value maximal polymorphism and as many free theorems as possible, at the expense of everything else, adding an Ord constraint is indeed a problem. But I don’t think that assumption makes much sense here, there are more things to consider.
2
That fans of static typing prefer to assume coherence even if not enforced (as in Scala) rather than what’s enforced still puzzles me. OTOH, Scala needs applicative functors before associated types on implicits become usable; there’s a PR possibly implementing them in Dotty.
1