Quasar VS Kategory

Java 21 doesn't retrofit green threads though. Quasar [0] is a library that implemented fibers for Java and the main developer pron has joined the OpenJDK development team. All that was necessary for first party support is to make the JDK libraries yield when blocking.

Adopting async isn't impossible at all, there is very little demand for it.

[0] https://docs.paralleluniverse.co/quasar/

Third party options have been around for nearly a decade now: https://docs.paralleluniverse.co/quasar/

Quasar Fiber (https://docs.paralleluniverse.co/quasar/) is the equivalent implementation of goroutine in Java.

Even Loom architect Ron Pressler had something else in mind with his earlier prototype Quasar, with a spaceship demo.

I'd say because of Erlang. Loom's architect was building a bytecode-modifying (with a javaagent) lib named Quasar before he joined Oracle. The project page mentions a news titled "Introductory blog post: Erlang (and Go) in Clojure (and Java), Lightweight Threads, Channels and Actors for the JVM." in May 2, 2013.

Yeah, it has nice funcional capabilities and libraries (like Arrow[0]).

[0]: https://arrow-kt.io

Last but not least, Scala is currently the language with one of the best effect systems in my opinion (https://zio.dev/). Kotlin for example has copied the approach with https://arrow-kt.io/ which I think is great actually. But when comparing Scala and Kotlin here, Scala wins by a large margin, it is a completely different world. It's like building a highly concurrent system in Erlang vs C.

Of course, if you don't want to learn things like union types, traits/typeclasses and effects (similar to async/await but more powerful) you will be annoyed by Scala. But once you learned them, you can never go back.

In my own code, I started to use explicit error handling. I'm currently experimenting with Result (from https://github.com/michaelbull/kotlin-result) and Raise (from https://arrow-kt.io/).

Are there any more-or-less established functional crates in Rust (similar to Kotlin’s Arrow)?

I wonder how the community sees adding Arrow besides standard Kotlin language features. Is it something that's still considered useful or just redundant and causing more confusion?

You can define a function like context(EitherEffect) suspend fun MyType.bind(path: String)like the ones in https://github.com/arrow-kt/arrow/blob/b608a054a5318fe57d7055c35bb64a5effb053b6/arrow-libs/core/arrow-core/src/commonMain/kotlin/arrow/core/computations/either.kt