14 Sep
2019
14 Sep
'19
2:51 p.m.
On Fri, 13 Sep 2019 at 13:54, Henning Thielemann < lemming@henning-thielemann.de> wrote:
On Tue, 10 Sep 2019, David Feuer wrote:
Every time I reach for Data.Function.on, I feel like a total dolt for having to import a module to get a function whose implementation is barely longer than the import. And it's a really good function too! Can we please add it to the Prelude? on :: (b -> b -> c) -> (a -> b) -> a -> a -> c (.*.) `on` f = \x y -> f x .*. f y
Most of the time I would use this I can use the more specific 'equating' and 'comparing'.
Does 'equating' exist in base now? I've always missed having that function in the past, and defined it myself many times. Erik