[Haskell-cafe] Textbook example of instance Foldable ((,)a)

[Barak A. Pearlmutter]

On Tue, 24 Nov 2020, Henning Thielemann wrote:

> If people would use custom pair types we would not need Foldable on pairs,
> at all.

To be fair, if people would use custom pair types we would not need
*pairs* at all.

--Barak Pearlmutter