ZIO VS Http4s

The first point is about a fucking conference in 2016, in which the organizer invited several people with a process (and thoughts) explained here https://degoes.net/articles/lambdaconf-controversy aimed at being blind to sex/religion/political views etc. He repeatedly stated to be in a strong disagreement with "white supremacist" views and the such. The first words of the ZIO's code of conduct are precisely about that btw https://github.com/zio/zio/blob/master/docs/about/code_of_conduct.md, and zio follows the scala code of conduct. You can agree or disagree about whether "allowing that person, selected in the way described above (without any preference at all for white supremacists of course), to speak precisely about one particular topic and only if they adhere to the code of conduct" is "giving them a platform to share their ideas", but even if you do think that the first approach is completely wrong, it's a pretty big jump from here to accuse the person holding that view (actually a less-strong version of it) of being a white supremacist themselves and the same of all people that associate with that person (the organizer) and stalk and harass them for years on end

Since you are talking about an IO monad, maybe ZIO (https://zio.dev/) offers some interesting ideas. Rather than an IO monad, ZIO is a family of IO monads with type parameters to support user-defined environments and error types.

ZIO (interoperates with TypeLevel to some extent)

please show me something like this: https://akka.io/ or this: https://zio.dev/ or this: https://github.com/milessabin/shapeless

Here is link number 1 - Previous text "ZIO"

Nothing like cats or ZIO for Kotlin. I do hope I don't have to explain why Kotlin Arrow is not a good replacement.

ZIO on the other hand doesn't rely on those concepts, so I guess it could be possible ? But I'm not too sure the code would look great without Scala's for-comprehensions and there may be other blockers... By the way there's been some work done in ZIO to provide a Java facade : https://github.com/zio/zio/pull/383. Not sure the interop on that would work so great tbh.

If you want something more powerful, pure-functional and you need to do complex, concurrency-heavy operations, have a look at http4s: https://http4s.org/

I don't think this is toxic but still, it doesn't sit well with me: https://github.com/http4s/http4s/issues/4718

http4s

Here is a possible sketch with the functional http4s library. In http4s, both Http clients and servers are modelled as functions from Http requests to an Http response generated from an IO action. This would be like a function Request => IO[Response], which in http4s is called an HttpApp.

Http4s: https://http4s.org/

Have you checked http4s? I'm using it as a lightweight HTTP server with routing, etc. It might be not your cup of tea, if you don't use pure functional programming, etc, though.

The other day I was also trying to get rid of akka stack and replaced it with http4s for server and sttp for client (http4s websocket client support is in open state for more than 5 years for now: https://github.com/http4s/http4s/issues/330). It still works pretty well, especially since they both can be built from fs2 steams.

http4s, https://http4s.org/, its a good lightweight framework for building IO based REST APIs.