Hi! I don't know yet the abstractions in arrow to ...

# arrow

[kluck]

Hi! I don't know yet the abstractions in arrow to achieve what I'm trying to do. Basically, I'd like to do some switchMapping. Here's a very simple example of what I'm trying to do:

fun <T, E> IO<T>.setState(handleError: (Throwable) -> E, onSuccess: (T) -> IO<Any>) = IO.fx {
        val state = ![e-mail]()
        state.fold(
            { handleError(it) },
            {
                // Other stuff happening…
                !onSuccess(it)
            }
        )
    }

    @Test
    fun test() {
        val handleError = { t: Throwable -> println("Error: ${t.message}") }
        val onSuccess = { bool: Boolean ->
            IO.fx {
                println("Starting")
                !effect { delay(5000) } // --> SwitchMapping should happen around here
                println("Finished with value $bool")
            }
        }
        // Here, this is what I don't know how to "Observablify" to send multiple events
        IO.just(true).setState(handleError, onSuccess).unsafeRunAsync {}
        IO.just(false).setState(handleError, onSuccess).unsafeRunSync()
    }

What I expect is:

Starting
Starting
Finished with value false // The other one should be "switchMapped"

I don't know how to have some kind of flow or observable with arrow, and I don't know how to switch map within it. Any guidance?

[pakoito]

IO is for single results, so flatMap is switchMap

[pakoito]

if I( understand the question correctly

[kluck]

Actually, I was looking for the multiple-result version of IO (or the arrow equivalent of a Flow maybe ?), and therefore the corresponding switchMap.

[pakoito]

cool

[pakoito]

so, multi-result for single consumer is called Queue

[pakoito]

because it's single-consumer it works with concatMap semantics by default

[pakoito]

you can build switchMap on top of it

[pakoito]

EDIT OUT

[pakoito]

something like that

[pakoito]

nevermind, that won't work

[pakoito]

hmmm

[pakoito]

it's feasible, just a bit complicated to implement

[pakoito]

I'll see if I can do it later today