How does it compare to HVM [0]? It is an alternative to GHC that in some cases is orders of magnitudes faster, at least from their benchmarks.

[0] https://github.com/HigherOrderCO/hvm

i thought the orders of magnitudes faster benchmarks were around lazy evaluation, and probably wouldn't apply here.

Roc uses perceus, which is a reference counting model that allows for opportunistic in place mutation if it is safe to do so. HVM is more like a fundamentally new evaluation model that is parallel by default. They are both very exciting, but HVM is much more radical and probably needs at least a few more years until it starts to be seriously practical.

> eager evaluation is a big improvement

Does it have any support for laziness? E.g. could one define the list of all fibonacci numbers similarly to Haskell's

    fib = let f a b = a : f b (a+b) in f 0 1