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Comment by mjhoy | Hacker News Reader

I love Purescript, but I think in some ways it is even more arcane than Haskell for a beginner.

e.g.,

    > :t (+)
    forall a. Semiring a => a -> a -> a
    
    > :t (&&)
    forall a. HeytingAlgebra a => a -> a -> a

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Agreed on both points, love it and a bit too wicked for new-comers. Elm is perfect there and should find its place into all kinds of educational contexts hopefully. Such a friendly ML language, I secretly call it "the Basic of FP/ML land" (an honour in my book; more modern equivalent might be Python there but you get the idea).

Also good that it's missing "advanced" stuff like type-classes, built-in monad/functor/applicative & friends. Good for teaching because students will be compelled to learn to write that themselves from the ground up. It's all lambda calculus under the hood anyway, and thusly representable "hand-made from scratch".

But it requires a different kind of skill altogether. A semiring is a concept in abstract algebra that’s quite independent from general functional programming.

That's kind of my point. Usually when you're just learning "general functional programming", you're thinking about, say, (+) as a function that takes two numbers, and returns a number, because you're at the stage of figuring out how something like

    fold (+) 0 [1,2,3]

works. Introducing "Semiring" as a concept at the same time can be a bit much for a beginner!

I do think it's a useful concept, and that Purescript is an excellent, intermediate-level FP language.

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