I submitted https://gitlab.haskell.org/ghc/ghc/merge_requests/644 but it might be still controversial. I'd like to get more opinions again.

Here's the list of proposed instances:

Foldable ((,,) a b)


Foldable ((,,,) a b c)


Traversable ((,,) a b)


Traversable ((,,,) a b c)


Functor ((,,) a b)


(Monoid a, Monoid b) => Applicative ((,,) a b)


(Monoid a, Monoid b) => Monad ((,,) a b)


Functor ((,,,) a b c)


(Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c)


(Monoid a, Monoid b, Monoid c) => Monad ((,,,) a b c)





The absence of Traversable instances for tuples feels quite inconsistent given that there are Bitraversable instances already.