Message: 2 Date: Thu, 17 Jan 2013 22:32:14 +0100 From: "dag.odenhall@gmail.com" Subject: Re: Simple addition to Control.Arrow To: Daniel D?az Casanueva Cc: Haskell-Libs Message-ID: Content-Type: text/plain; charset="iso-8859-1"

Should perhaps be noted that this exists in the lens package as "over both" and also for up to 9-tuples as "over each".

This was also said by #haskell, but it's simply not true, unless you claim (->) is the only Arrow people use. over both :: (a -> b) -> (a, a) -> (b, b) whereas my suggestion: both :: Arrow a => a b c -> a (b, b) (c, c) Anyway, judging by the response from the list there (unfortunately) doesn't seem to be that much interest. Kind regards, Merijn