Well, Rust has some kind of typeclasses, #deriving, stuff like that. If what parent means is "if you like the things Rust borrowed from OCaml and Haskell, check out Haskell", it's not unreasonable, especially if addressed to people coming from mostly-imperative languages (C or Python).
I agree that Rust and Haskell do feel mighty different in practice.
(Warning: not at all a Haskell expert, so please correct me if I'm wrong.)
Each language's deriving facilities aren't actually comparable, as Haskell's are actually generic whereas each Rust's are all hand-coded syntax extensions.
Also, I believe that it's possible for Haskell code to fail at link time due to libraries providing incompatible typeclasses (contributing to Cabal hell, perhaps?), whereas Rust traits have different restrictions such that if your library compiles, you know that your users will never experience failure due to the traits implemented by other libraries.
So even though the Rust devs have clearly taken some degree of inspiration from Haskell, there are enough subtle interactions with other systems that even the familiar features have a distinctly different feel.
I will say, though, that in my observations there have been more than a few people from iterative backgrounds who have said that familiarity with Rust was a useful stepping stone to Haskell. So even though I'd hesitate to compare the languages in absolute terms, in relative terms it's true that Rust is probably the iterative language with the most to offer to aspiring Haskellers.
What do you mean by Haskell's deriving being generic? As far as I know, Haskell can only derive a fixed list of classes, except for newtypes, which are sort of a different case. How the fixed list is implemented in the compiler isn't that important... on the contrary, at least vanilla Rust has a way to define arbitrary deriving-like extensions based on inspecting the structure at compile time (even if it's somewhat ugly), while vanilla Haskell has nothing of the sort.
> it's not unreasonable, especially if addressed to people coming from mostly-imperative languages (C or Python).
Perhaps not, but how it is brought up (and worded) feels a bit dismissive of Rust. Which would be fine, if it were not for the fact that the topic of the thread is Rust, and "try Haskell" comment is very drive-by.
I agree that Rust and Haskell do feel mighty different in practice.