> works really well in Rust and TypeScript too
And of course Rust and TypeScript were heavily influenced by Haskell... they just don't mention it and call things differently, to avoid the "monads are scary, I need to write a tutorial" effect. Though it's less about monads and more about things like type classes.
Imitation is the sincerest form of flattery.
> heavily influenced by Haskell... they just don't mention it and call things differently
Rust wikipedia says otherwise
Rust has typeclasses so that can't be it.
Rust's influence was OCaml, not Haskell. Its first compiler was written in OCaml. Its syntax directly looks like OCaml and C++ had a baby. It's got ML smells all over it. Haskell is not the sum of Hindley Milner-esque languages.
Personally, never enjoyed Haskell's syntax (or lack of it) and tendency to overthinking. But I did enjoy SML/NJ and OCaml to some extent.
Are type classes scary? PHP has had them since 2012.
They are different things.
What are different things?
Eli5:
Haskell type classes are not classes (like Java or PHP classes); they are comparable to Rust traits -- which are different from PHP traits which are comparable to Java/C# interfaces (with default impls; if you just want contracts you have... PHP interfaces).
A fundamental difference is that you can instantiate/implement a type class (or Rust trait) for any* type, compared to interfaces where each class declares the interfaces it implements. You can therefore create generic (forall) instances, higher kinded type classes, etc.
That conflates type classes with extension types, in type theory.
Actually in modern Java you can simulate type classes approach with a mix of interfaces and default methods implementations.
In C# you can have the experience more straightforward with extensions types introduced in C#13.
Then we have yet another way to approach type classes in Scala, with traits and implicits.
And so on, as I haven't yet run out of examples.
> Actually in modern Java you can simulate type classes approach with a mix of interfaces and default methods implementations.
Can you? The beauty of traits/type classes is that you can attach them to any type - in a world where 90% of the functionality of any piece of software is supplied by dependencies - external types which you cannot change - this is a vital feature.