On on (was: [GHC] #971: Add intercalate and split to Data.List)

On Mon, 30 Oct 2006, Jón Fairbairn wrote:

We can write “groupBy (\a b -> p a && p b)” [...]

You mean “groupBy ((&&) `on` p)”, right? ;) Do you consider on to be above or below the Fairbairn threshold, by the way? I think it is above the threshold since * we get rid of two lambdas, * we get rid of the duplication of p, * and, most importantly, it is easier at a glance to tell what the function does (assuming one knows about on). -- /NAD