groupBy Missing

[schnecki]

Hi,
I'm missing the groupBy function for lists/sequentials. Is there a reason why it's not there?

[schnecki]

And why is there no instance for Foldable on NonEmpty?

instance Foldable c => Foldable (NonEmpty c) where
  foldl' f a (NonEmpty xs) = foldl' f a xs
  foldr' f a (NonEmpty xs) = foldr' f a xs

Then groupBy could be implemented. But the current NonEmpty is quite unusable.