monadless VS ureq

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).

I also enjoyed using ureq as an http client.

After a quick check of the available rust http client libraries I opted for reqwest. It has a pretty simple API and it seems to be among the most used libraries for this matters. But I'm a bit concerned about all its dependencies so I might try ureq later.

Async is only useful when you have hundreds of connections open at the same time and idling most of the time; otherwise it's a liability. If your web API does not allow that (e.g. it has rate-limiting, which most APIs do), I suggest going with a client that performs blocking I/O and spawning threads if you need parallelism. https://github.com/algesten/ureq should fit the bill.

I think you'll find a lot of people claiming its overkill, but it will have excellent documentation for both sides, offer reasonable speed, and let you hash out the actual logic of your system without worrying too much about if your low-level implementation is correct. Two good frameworks for the server would be Actix or Rocket. For the client, i'd reccomend either using reqwest or ureq. From there, you can just set up a few POST endpoints, and get to going.

If you want an HTTP client with few dependencies and little unsafe code, take a look at https://github.com/algesten/ureq

Give ureq a try: https://github.com/algesten/ureq