Personally I do not like underscores. It can get real ugly.

So instead of:

    map3 f ( x, cmd ) ( y, cmd' ) ( z, cmd'' ) =

I will have to write:

    map3 f ( x, cmd ) ( y, cmd_ ) ( z, cmd__ ) =

https://github.com/Fresheyeball/elm-return/pull/4/files#diff...

And it affects package API too: https://github.com/elm-lang/svg/commit/40b761d66b48fcc28f5b5...

However that's just a matter of taste and does not deter me from continuing to use Elm.