Sergey Torgashov

I would say, there are at least two takeaways from the table: 1. Cats has got huge inconsistency amidst its support for collections: some collections are way more beloved than...

And one more thing I didn't reflect in the table, but which does concern me as well: all existing `groupMap`-like methods (`groupMap` and `groupMapNem`) actually use two parameter groups similar...

@TonioGela > The table seems really like an invitation to implement all the remaining n/a methods :D I would say, it would be really nice to have all the method...

> Along those lines, it seems to me that we could implement groupByMap-like operation on Traverse itself. But why `Traverse`? To me it seems like `Foldable`/`Reducible` should be just enough...

It regards to the generalization... Let me expand a little bit more on that with an example: There are two similar mehtods in `NonEmptyList`: `groupByNel` (groups into NE-List) and `groupByNec`...

> are there any datatypes that implement Foldable but do not implement Traverse ? Good question, and honestly, I don't know :) But if `Reducible`/`Foldable` were introduced for a reason,...

> Alternatively, we could possibly add this method to NonEmptyAlternative which then knows the structure of the thing it is building That is an interesting idea... We can definitely give...

The only issue I see here is that when using such an approach, a user will be forced to specify not only a desired output collection type (which is required...

A couple of thoughts from my side. First of all, just to note: `NonEmptyList` also lacks `appendAll` method. So I think that it would be nice to add them both...

@saeltz looks good to me, thanks for your efforts! If you believe your PR is pretty much ready, would you mind pulling it out of the "Draft" state please?