Oooh I didn't know that was a thing!

Yes, I want this but in a fast, compiled systems language like rust.

Haskell is a fast, compiled systems language like Rust (or rather, Rust is like Haskell).

Are you sure about that? My understanding is that Haskell programs generally run much more slowly than their C counterparts because of all of Haskell’s magic. Like lazy evaluation and memoisation and however Haskell manages memory.

Rust certainly borrows from Haskell. Like all good languages. But I’m not aware of Haskell beating rust in program performance & memory usage benchmarks.

SeL4 was first written in Haskell and proven correct in Haskell. Then, with a great many years of effort, ported to C and proven correct there. If Haskell were a viable systems language, I suspect the kernel would not have been converted to C.

Yes, I'm sure about that. I said that it is a systems language, not that it is as fast as C! I don't mind if your terminology excludes Haskell from being a systems language, as long as it also excludes Go. They are both managed, garbage collected, fast languages.

> Like lazy evaluation and memoisation

Yes, that causes performance impact. If you don't want the performance impact then don't write code that uses those behaviors. Sure, that rules out large parts of the ecosystem, but I said Haskell was a systems language not that its ecosystem was generally suitable for systems programming.

> however Haskell manages memory

No, Haskell's memory manager is world class, with two (at least) tunable garbage collectors.

> But I’m not aware of Haskell beating rust in program performance & memory usage benchmarks

Nor am I!

> If Haskell were a viable systems language, I suspect the kernel would not have been converted to C.

I suspect they converted it to C because you can't write a kernel in a managed language with a garbage collector.