monadless VS async-trait

Well `RecordWildcards` has been around for 14 years... but even without it instead of `{..}` you'd just have `_`s. The main thing that is different is that your Kind example had nested case statements while your Haskell example tried to match everything on one shot, which makes for a non-equivalent comparison.

> Not sure how that could work, though. Idris had an interesting syntax, but IIRC it wasn't general.

I assume you're talking about idiom brackets for applicatives? The general syntax is given in something like https://github.com/monadless/monadless. The idea is to basically take async-await syntax and generalize it to any monad.

So e.g. your `Maybe` example (using `!` for the equivalent of `await` for concision) would look like

  Maybe {

> If anything, async-await feels like an extremely non-functional thing to begin with

It, like many other things, forms a monad. In fact async-await is a specialization of various monad syntactic sugars that try to eliminate long callback chains.

Hence things like Haskell's do-notation are direct precursors to async-await (some libraries such as Scala's monadless https://github.com/monadless/monadless make it even more explicit, there lift and unlift are exactly generalized versions of async and await).

As of today, async functions in traits are not natively supported by Rust. Fortunately, David Tolnay got our back covered (one more time): we can use the async-trait crate.

You might want to check out https://github.com/dtolnay/async-trait to be able to declare async functions in a trait.

Also async-trait (GitHub), dtolnay has done some great work!

Does async-trait count as a trick or hack? It's not my hack, but it's a workaround/hack that I use every single day.

This macro goes a very long way toward solving the problem: https://github.com/dtolnay/async-trait

I'm still learning async to I cannot answer all the questions. First of all, I use this -> https://github.com/dtolnay/async-trait to take care of the async-inside-traits mess.