I'm ever so slightly +1 on this proposal.
Why? Because it gets reinvented every 4 months, and by just adding it we can stop having this discussion.
I hereby proposed there exists a "co-Fairbairn threshold", the point at which the traffic caused by fighting against adding a commonly reinvented simple composition outweighs the pedagogical gain of pushing people to understand the simpler parts. OK, you have me convinced. You should put these thresholds of yours on
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 19/07/14 14:44, Edward Kmett wrote: the GHC Wiki or something. ;-)
That said, I'd prefer it live alongside comparing, and not get pushed redundantly around to other modules. I suggest: equating :: Eq a => (b -> a) -> b -> b -> Bool equating p x y = (p x) == (p y)
in Data.Eq, exposing it with module Data.Eq ( Eq(..), ) where If this sounds good I can write a patch for it, test it & upload it to phab to have it built & reviewed by austin and you. :-) - -- Alexander alexander@plaimi.net https://secure.plaimi.net/~alexander -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iF4EAREIAAYFAlPKaZ8ACgkQRtClrXBQc7WqgwEAgmlzkK+/JdsGDZ2OabyNPE8W y2zffqFTvus/GYO1S00BAKC3ncHM5R01sgrZfE8BhstzNNQ3JnTF5CoReBUedc4R =u6pc -----END PGP SIGNATURE-----