Is there a relationship between the Arrow core type `Effect` and the `arrow-fx` projects? I've been ...

# arrow

[Wesley Hartford]

Is there a relationship between the Arrow core type Effect and the arrow-fx projects? I've been using Effect to model effects such as calls to a database or web service. Is there a recommended way to use the features of arrow-fx to add retries to an Effect?

[simon.vergauwen]

Hey @Wesley Hartford,

There is no relation between the two. Arrow Core complements the Kotlin Std, and Arrow Fx Coroutines complements KotlinX Coroutines.

In Arrow Fx Coroutines there is Schedule which can be used to easily build complex retry systems. https://arrow-kt.io/docs/apidocs/arrow-fx-coroutines/arrow.fx.coroutines/-schedule/

Everything in Arrow Fx can safely be composed/combined with Effect.

[Wesley Hartford]

Thanks @simon.vergauwen, I think I've got my head firmly wrapped around most of arrow core, but arrow fx is still mostly a mystery to me.

[simon.vergauwen]

Feel free to ask any questions you have. Fx is pretty small, it offers Iterable.parTraverse (parMap in 2.x.x). parZip to combine independent functions together in parallel. We're adding types like CountDownLatch soon, Kotlin MPP suspend alternative of the Java one.

So it offers some concurrency utilities alongside KotlinX Coroutines

[Wesley Hartford]

Thanks, I know I've been missing a suspending implementation of the CountDownLatch.

[simon.vergauwen]

https://github.com/arrow-kt/arrow/pull/2854