can you explain it a bit? :smile:

# arrow-contributors

[pakoito]

can you explain it a bit? 😄

[Jannis]

The basic structure of it is: You create a policy datatype which describes how to repeat/retry computation. That type is an instance of some typeclasses like alternative/applicative/monoid etc and has some powerful composition functions. Then all you need to do is call a retry/repeat function with that schedule.

[Jannis]

some slides that show this

[Jannis]

https://de.slideshare.net/jdegoes/zio-schedule-conquering-flakiness-recurrence-with-pure-functional-programming-119932802

[Jannis]

the talk for it is also good, the interesting bits start somewhere in the middle, i'll look up the slide number ...

[Jannis]

at like slide 40

[Jannis]

I also did a port of this once, but I think this can be done better for arrow

[pakoito]

does it require any of the ZIO environment internals? that’s our bane because we depend on coroutines for threading and such

[Jannis]

nah, it is much older than that afaik

[raulraja]

if anyone attempts this try it over EnvFx

[raulraja]

https://github.com/arrow-kt/arrow/blob/ff%2Fattempt-beanchmark/modules/effects/arrow-effects-data/src/test/kotlin/arrow/effects/EnvFxExample.kt

[raulraja]

That is ZIO + Environment over the suspended system

[raulraja]

Which in 0.9.0 will become EnvIO if we are able to fix the cancelation and stack safety which are still missing there

[Imran/Malic]

Can you explain what some implications are from EnvFx. I do understand the code, but what can I do with it. Is it something like a Store for all my Dependencies? Do I even need it if I use a Reader Monad? //I did not yet use a Reader Monad for some of my projects

[pakoito]

It's like IO but you can ask() for the environment that it carries. So it's like extension functions and receivers but embedded on your concurrency framework

[Imran/Malic]

Damn, so I could carry the computation of a DI framework?

[pakoito]

ye

[Imran/Malic]

I have a question I am trying to model multiple Services (API calls) as Products and these services are self-sufficient. Is there a better way to model this as Coproducts, because at the time I stumbled over it, I thought "this is it". I am not sure If I can then sum multiple Coproducts (API Services) into a type class.

To be specific, is this a good way of modeling or am I on the wrong track here.

[pakoito]

Use tuples or create a new interface to provide them

[pakoito]

https://arrow-kt.io/docs/patterns/dependency_injection/

[pakoito]

try this

[Imran/Malic]

Thanks, I'll get back to you, when I figure it out.

[raulraja]

@Imran/Malic https://gist.github.com/raulraja/0088c4d41c3fdcf5aa77e73316f4af22

[Imran/Malic]

didn’t you send it before 🙂