Kategory VS Arrow Meta

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

As of right now, Arrow Meta is the only library I am aware of with which you can productively write compiler plugins.

Thanks for the example, that's interesting.

Note that Kotlin has union types through this compiler plugin: https://github.com/arrow-kt/arrow-meta/issues/570