> OK. I'll create two quick proof-of-concept repos under
> https://github.com/schemedoc -- one for the types and one for the
> documentation -- based on your current S-expression files. Let me know
> whether you find the layout reasonable. If not, we can change it. Let's
> try to find an approach where we can minimize duplication of effort.
>
> I'll notify in this thread when I'm done. Should take a couple of days.

Sorry, this is getting delayed. There's a start at
https://github.com/schemedoc/signatures but I should still cross-check
with the type systems of a few established languages (e.g. SML, Haskell,
Koka).

I think it's possible to write the type signatures using an abstract
notation that a Scheme script can convert to actual type systems.