but in the middle, the traverse wraps the whole fl...

# arrow

[Pagoda 5b]

but in the middle, the traverse wraps the whole flow into an effect F

[simon.vergauwen]

Not 100% sure what you mean with this?

[Pagoda 5b]

let me try to simplify the code to give you the hang of it

[Pagoda 5b]

//the first fx.monad composition is only to sequence multiple effectful ops
fun <F> MonadDefer<F>.doThis() = fx.monad {
    val (manager) = ...some stuff
    later {
        manager.on<Event>().k() //<- switch to kotlin flowK
            .filter (...)
            .traverse(this@doThis) { ev ->
                //call that creates a Kind<F, A>
             }.map {
                 it.value() //<- unwraps the FlowK
                     .flatMap { result ->
                           createAction(result).asMono()
                     }.subscribe()
             }
    }.bind()
}

[simon.vergauwen]

Oh right okay, I see now. You’re using Flow within F.

[Pagoda 5b]

so, until I call traverse… we got a flowK, but traverse extracts some other Kind<F, _> that now contains the new flow

[Pagoda 5b]

I’m currently seeing that I might be wrapping everything in a later that gets bind()-ed, but I might’ve forgotten to do the same with the “wrapped” effect?

[simon.vergauwen]

You’re here basically reacting to events that you get from manager, right?

[simon.vergauwen]

So you’re not interested in exposing that stream since you return F instead?

[simon.vergauwen]

Btw are we talking about Flow or Flux? If there is an integration package for Flow we’d love to have it in Arrow.

[simon.vergauwen]

Also if you’re interested in porting the RxJava Concurrent instances to Reactor that’d be cool 😄 I’d love to help you out with anything

[Pagoda 5b]

Sorry, my bad, it’s FluxK

[Pagoda 5b]

I get confused easily with reactor’s terminology, not used to it

[Pagoda 5b]

this is a really “side” project

[Pagoda 5b]

I don’t work enough on kotlin to invest so much on it now, I’m sorry 😅

[simon.vergauwen]

No problem 🙂

[Pagoda 5b]

I didn’t get your meaning about not being interested in the stream (I think you’re referring to the reactive flow here, right?)

[Pagoda 5b]

I have this flow of events and I need to respond via messaging as a mono event

[simon.vergauwen]

Yes, what is the return type of that function?

[Pagoda 5b]

with the added complexity that my internal response depends on a wrapped effect value

[simon.vergauwen]

Let me whip up something of what I think could work for you

[Pagoda 5b]

so if I simply subscribe, the internal effect wouldn’t be evaluated, so I’ve tried to do the traversal to get it out and compose it with other effects

[Pagoda 5b]

to give you more info, I’m trying to integrate arrow with this discord reactive integration: https://github.com/MinnDevelopment/jda-reactor#reactiveeventmanager

[Pagoda 5b]

you can see the example code there…

[simon.vergauwen]

This is a small example that wraps the stream of Events from the manager, and executes an effect F for every Event. This doThis(): Kind<F, Unit> finishes when all events are processed.

Untitled.kt

[simon.vergauwen]

I included all imports and the mocks I used to make the types align 🙂

[Pagoda 5b]

Thank you so much @simon.vergauwen, I’ll definitely look into that

[Pagoda 5b]

I’ll let you know

[Pagoda 5b]

@simon.vergauwen I’m missing one thing, what does the ! prepended to the manager.onEvent... at line 27 does?

[Pagoda 5b]

is the result a whole suspended effect that needs be evaluated?

[simon.vergauwen]

ah you could also replace it with val (unit) = manager.onEvent().k() or .bind() at the end

[simon.vergauwen]

The result of the last flatMap on manager.onEvent().k() returns Unit but you still need to execute it within fx with component1, bind or not

[Pagoda 5b]

nice, didn’t know that shortcut (I’ve only seen it used with effect{...} in examples and didn’t make the connection 😁

[simon.vergauwen]

Those 3 are all aliases 😉