Not sure if that's really a proof, as it could be the exact combination of language features that makes up the slowness. For example traits, non-ordered definitions in compilation units and monomorphization probably don't help. GHC also isn't a speed demon for compilation.
But sure, LLVM and interfacing with it is quite possibly a big contributor to it.
Haskell isn't the only language around with complex type systems.
However, it is actually a good example regarding tooling, as the Haskell ecosystem has interpreters and REPL environments available, for quick development and prototyping, something that is yet to be common among Rustaceans.
Indeed, but its compile times aren't much better than LLVM, at least one year ago.
Ideally we would be having the F# REPL/JIT, plus Native AOT for deployment, as comparable development workflow experience.
Naturally F# was chosen as example, because that's your area. :)
Not being negative per se, I also would like to have something like Haskell GHCi, or OCaml bytecode compiler, as options on rustup, so naturally something like this might eventually come.
Based on a first hand account I read (but cannot source offhand) Rust's slow compiles are because anytime there was a tradeoff involving compile time at the expense of something else they'd always choose that something else. Not cause they hated fast compilation, guess it just wasn't high on their priorities.
