Am Mo., 23. Nov. 2020 um 16:32 Uhr schrieb Sebastiaan Joosten < sjcjoosten+haskell@gmail.com>:
[...] We obtain: length (a,b) = length [b] = 1
Quoting my former self ( https://mail.haskell.org/pipermail/libraries/2017-April/027905.html), you get even more "fun" stuff with lots of potential for late-night debugging hours: maximum (3,2) => 2 minimum (4,5) => 5 sum (6,7) => 7 product (8,9) => 9 Yes, you can think of (X, Y) as "Y with context X" or "a one-element container with Y in it", but is this really what comes to your mind first? I still highly doubt that. The Foldable-Traversable-in-Prelude change was largely a good thing, but very surprising (and not really needed) changes coming stealthily with it were only communicated when it was already too late... :-/