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Comment by zoul | Hacker News Reader

Considering that Elm seems to be by far the most stable, usable and used alternative, just dismissing it for the lack of typeclasses seems a bit short sighted to me. Is this a case of avoiding success at all costs? :)

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Elm can be looked at like Haskell on training wheels, in a good way, and that simplicity very likely contributed to its popularity.

We already tried Fay as a team (15kloc codebase to write an IDE), which was literally Haskell without type-classes. We've learned that we want type-classes, YMMV.

There are some ways in which Haskell's type system actually makes it significantly better at Elm's core job than Elm itself.

Type classes could certainly be argued to be one of those things, but also just existential types makes "reducers" a lot more pleasant to work with.

Check out e.g. Edward Kmett's library or read e.g. Gabriel Gonzales' post on folds if you want to know more.

[1] http://hackage.haskell.org/package/folds-0.7.5/docs/Data-Fol...

[2] http://www.haskellforall.com/2013/08/composable-streaming-fo...

Yeah, but I’d love to see the average JavaScript developer get up and running with Haskell in just two weeks.

Elm confronted a dizzying amount of abstraction and category theory prevalent in Haskell implementations of FRP and over time converged on a solution so amusingly simple that it ended up dropping the FRP branding entirely because it just seemed silly. Elm absolutely succeeded and gained real-world traction because it took what was at that point an overly academic and unsuccessful idea and aggressively pursued simplification. Perhaps one could argue that this pursuit had a cost as well -- e.g., the lack of typeclasses -- but I just don't think Elm would exist without that driving mission.

Is Elm still dependent on one maintainer[0]?

[0]https://news.ycombinator.com/item?id=16511478

Yes. Until Evan stops gatekeeping which packages are allowed to be published, Elm is a high-risk experimental language best suited to experimental projects.

>considering that Elm seems to be by far the most stable, usable and used alternative

I wonder, does Elm not having type classes is actually a feature that boosted its success, or is it just missing because of the author stubbornness ?

I think Elm did right into focusing in SPA rather than being yet another language compiling to JS.

> does Elm not having type classes is actually a feature that boosted its success

I dont think so. It did help make errors very straight forward and prolly also keeps compile times low.

The author's stubbornness is, in my view, more in that he does not support (actually prevents where he can) making Elm usable outside of the browser (like what Node did to JS).

Seems like it. There are some tasks in Elm which would benefit from typeclasses but in my experience they're not so common to be much of a concern. Sure, I'd like typeclasses but I'm not dropping down to JS just because of their absence.

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