23 Apr
2017
23 Apr
'17
6:56 a.m.
On Sun, Apr 23, 2017 at 10:06:00AM +0000, Jonathon Delgado wrote:
If a tuple only has one value, why do functions for operating over sets make sense at all? I can see from your explanations why the answers could be considered correct (if a particular convention is assumed), but why does the operation make sense at all? It seems like we're asking for the length of a single value, its product, etc.
I can only guess: consistency. Once you create an instance of `Foldable` you instantly get some functions "for free". Among those are foldMap, foldr etc. *and* sum, length and friends. I cannot see an occurrence where writing `length (x, y)` instead of 1 makes sense.