This sentence in the Arrow guides is misleading: "...

# arrow

[Attila Domokos]

This sentence in the Arrow guides is misleading: "Complementing the Kotlin Coroutines library, Arrow Fx adds an extra layer of safety to concurrent and asynchronous programming so you’re well aware of where effects are localized in your apps."
TIL - Arrow is not using JetBrain's coroutine library (https://github.com/Kotlin/kotlinx.coroutines), the wording should be "Competing" or "As an alternative to the Kotlin Coroutines library". Thoughts? (Thanks to @simon.vergauwen for chatting with me about it.)

[Attila Domokos]

The section I am referring to is in the Conclusion section on this page: https://arrow-kt.io/docs/fx/#conclusion

[simon.vergauwen]

Most accurately described it would probably be something like

“Arrow Fx offers a purely functional lazy runtime for Kotlin’s suspend system with side-effect tracking and monad comprehensions. It contains an IO type, which is equivalent to suspend () -> A and many powerful concurrency primitives like Semaphore, Ref, Promise, etc. They all guarantee resource safety, while offering powerful concurrent and parallel combinators and automatically cancellation support. (In the future also suspend () -> Either<E, A>)

In contrast to KotlinX Coroutines, which offers an eager implementation of Kotlin’s suspend system with cooperative cancellation support and a cold stream implementation.”

[raulraja]

With meta suspension and IO are isomorphic and also coherced automatically

[raulraja]

So all the IO api will be projected over suspend functions eliminating most of the wrapping in favor of imperative syntax across the board that is easy to newcomers and people not used to nested style in FP

[raulraja]

When we wrote that conclusion IO was not as far from coroutines as it is now but it clearly differentiates not just in eager vs lazy but in the way it automatically handles cancellation and safe resource handling

[raulraja]

We believe for a fair ecosystem of suspension, cancellation should be part of the std lib suspension intrinsics