Hi, I have such “nice” result: ```val results: List<IO<Either<ListenerError, Unit>>&g...

# arrow

[dnowak]

Hi, I have such “nice” result:

val results: List<IO<Either<ListenerError, Unit>>> = ...

and want to convert it to IO<Either<ListenerError, List<Unit>>>
This is what I got to achieve it:

val r = results.sequence(IO.applicative()).fix().map { l ->
    l.fix().sequence(Either.applicative()).fix().map { list ->
        list.fix()
    }
}

Is there any better/nicer way?

[simon.vergauwen]

Not really, you could work with EitherT.

results.map { EitherT(it) }
       .sequence(EitherT.applicative(IO.applicative()))
.map { it.map { it.fix() } }

but doesn’t much nicer results due to fix().

disclaimer, wrote this from memory

[dnowak]

Thank you for advice 🙂