[ihnorton]

    Really annoyed by the borrow checker? Use immutable data structures
    ... This is especially helpful when you need to write pure code similar to that seen in Haskell, OCaml, or other languages.

Are there any tutorials or books which take an immutable-first approach like this? Building familiarity with a functional subset of the language, before introducing borrowing and mutability, might reduce some of the learning curve.

I suspect Rust does not implement as many FP-oriented optimizations as GHC, so this approach might hit performance dropoffs earlier. But it should still be more than fast enough for learning/toy datasets.

[steveklabnik]

> I suspect Rust does not implement as many FP-oriented optimizations as GHC

It's more complicated than this; sometimes FPish code is super nice and easy and compiles well (see the zip example in this very thread!) and sometimes it's awkward and hard to use and slower.

[jayy-lmao]

Personally I’ve done a small amount of reading of the Hands On Functional Programming in Rust book. I’ve also found Scott Wlaschin’s F# resources quite transferable (though you may run into some issues with passing async functions around as arguments).

[dgb23]

I think proper immutable data structures can be quite fast without sophisticated compiler magic if they are read and cloned often (cloning is an abstraction) and are generally long lived.

Rust makes mutations safe, but immutability has benefits outside of safety.