What kind of progress has been made in modelling IO in functional programming? I see it as a goal on https://futureofcoding.org/about. Is the current solution basically Rx? And has anyone taken the ideas of Rx and been able to fold them cleanly into a programming language rather than as a separate library?

are you familiar with algebraic effects? im not particularly familiar with Rx as an alternative to IO, but effects provide a way to "break up" the "IO monad" and interpret effects in a more granular way. unisonweb.org is a language that implements effects in the form of abilities. koka and eff are two other languages that work in the same space

No, I am not! Thank you! I will go study that

if you prefer working in a more widespread language, haskell has several effect-management libraries, particularly polysemy and freer-simple, and hasura/eff is one under development

OK, this looks really cool. Essentially, it is an implied mutable interface input into the function. Using the same tools as generics, you can have lambda arguments capture these arbitrarily. I might replicate a similar thing in the language I am working on, though perhaps not in quite the same way.

async/await

is interesting as an integration of async directly in languages.