I want to execute a list of of `IO` actions all t...

# arrow

[Michael Marth]

I want to execute a list of of IO actions all together with one call to unsafeRunSync. I know in Haskell there is sequence - is there a similar construct in Arrow?

[Jannis]

sequence in haskell comes from the Traverse typeclass and is defined as traverse id or similar. We have the same construct and it should exist for every datatype that has an instance of Traverse

[Jannis]

I would love to link some docs but the pr for it is wip 🙈
The code for it is here https://github.com/arrow-kt/arrow/blob/master/modules/core/arrow-core-data/src/main/kotlin/arrow/typeclasses/Traverse.kt

[Michael Marth]

Thanks, Jannis! No doc needed (as far as I can see now). Using ListK should do the job ...

[aballano]

@Michael Marth I believe what you're needing is just parSequence

[aballano]

listOf(IO { 1 }, IO { 2 }).parSequence(...)

[aballano]

https://arrow-kt.io/docs/apidocs/arrow-fx/arrow.fx.typeclasses/-concurrent/par-sequence.html

[Michael Marth]

Yes, that's actually what I have ended up with 🙂