I would like to renew the effort to improve the documentation of base and, through that, include more doctests in the haddocks. Some usage of doctest can already be seen in Data.Maybe and Data.Functor. I would like to spread its usage to the rest of base.

Being new to the GHC development world, I would love to have your opinion on the matter.

Cheers.

cc @carter, @bgamari, @phadej