```listEithers.map { it.toDomain() }.traverse(Eith...

# arrow

[carbaj0]

listEithers.map { it.toDomain() }.traverse(Either.applicative(), ::identity).map { it.fix().toList() }

vs

listEithers.map { it.toDomain() }.traverseEither { it }

[simon.vergauwen]

Yes, those examples are equivalent.

I wonder what type listEithers is. listEithers.traverseEither { it.toDomain() } should also be possible.

[simon.vergauwen]

traverseEither { it } == sequenceEither()

[carbaj0]

virtual.traverseEither { it.toDomain() }
                    .flatMap { virtuals ->
                        physical.traverseEither { it.toDomain() }
                            .map { physicals ->
                                AccountState.CardCreated.MultipleCard(virtuals, physicals)
                            }
                    }

[carbaj0]

do there are a more idiomatic way to build this?

[simon.vergauwen]

You could write this with zip (or either { }).

virtual.traversEither(::toDomain)
  .zip(physical.traverseEither(::toDomain))
  { vs, ps ->
    CardCreated.MultipleCard(vs, ps)
  }

[carbaj0]

yeah! Thanks Simon i learn a lot with you 🙇‍♂️