Adding `mapInF`

[typelevel]

Adding `mapInF`

[danicheg]

As for me, it's a bit confusing to see map and F[_] go together in one contract. Basically one can use traverseIn + flatten. So maybe we can have flatTraverseIn. Though, it also could be confusing since it conflicts with the basic flatTraverse contract.

[benhutchison]

As @danicheg notes, its traverseIn + flatten. flatTraverse in Cats take a function f: A => G[F[B]] so thats what Daniel means by "conflicts".

I guess it comes down to, is traverseIn + flatten common enough to justify a shortcut? Im not seeing it but open to being persuaded..

[falconepl]

You're right. At first, it looks like mapInF would be a useful addition - especially when looking from a perspective of e.g. avoiding EitherT/OptionT in favor of Mouse's flatMapIn, flatMapF etc. (if someone prefers that style). But like you've said, there's traverseIn + flatten and maybe it's not such a common combination to have an alias for that.

Hopefully, at least someone looking for mapInF in the future will be able to find this issue and see that mapInF is just traverseIn + flatten.

Thanks for the feedback! I'm closing the issue