[pyrale]

It is that even without an open typeclass system, these specific typeclasses have been a common request for a long while.

I have worked at a few elm places, there is always a dict-for-everything dependency or local implementation.

[1-more]

Haha we may have worked together. Equatable has been a theoretically huge, actually OK hole in my opinion because it _can_ lead to runtime crashes but never has in any code I've written (\_ -> () == \_ -> () is a runtime crash). So I'm glad to see something more robust than "just don't do that." And "hashable" as the real thing you need to implement Set/Dict is a good idea imo. I'm sympathetic to keeping "comparable" closed and even smaller than it is for the reasons in this discussion [0]. In my perfect world, String would not be comparable as-is because string comparison should be locale dependent. Right now string comparison just ends up using JS's < operator which compares as a list of code units. So I'd like to be able to have a Set of Strings or a Dict with String keys without having the footgun of being able to think that I've alphabetized a list when all I've done is annoy a user by putting Área after Zapato and not between Azul and Barcelona.

But I agree with you that the current solutions for Set/Dict all have one problem or another: You can use elm-sorter-experiment [1] but then you are writing a sort function and passing it around and maybe you don't want the overhead of that. You can switch to the Lamdera compiler and use containers [2] but then it's a different compiler and a you need to tweak your options slightly to compile an Elm project as an Elm project in it and it could get out of sync with the Elm compiler (extremely unlikely though). You can use any of the list/dict implementations that are really just lists with O(n) everything under the hood. So maybe this hashable type is going to make things better, idk.

[0] https://github.com/elm/compiler/issues/774#issuecomment-3472...

[1] https://github.com/rtfeldman/elm-sorter-experiment

[2] https://github.com/lamdera/containers/tree/main