Bitraverse type class

[adelbertc]

No description provided.

[ceedubs]

This would extend Bifoldable, which it seems like people have agreed on adding in #94 but that nobody has gotten around to yet.

[ceedubs]

oh and 👍 :)

[adelbertc]

Does anyone have a use case for this?

[travisbrown]

I've used both bisequence and bitraverse fairly often, for things like a more generic zip:

scala> import scalaz._, Scalaz._
import scalaz._
import Scalaz._

scala> (some('a'), some(1)).bisequenceU
res0: Option[(Char, Int)] = Some((a,1))

…or printing / logging both sides of an option, etc.

[adelbertc]

working on this