Am Samstag, den 20.02.2010, 10:47 +0000 schrieb Andrew Coppin: > I just discovered the highly useful function Data.Function.on. I vaguely > recall a few people muttering a couple of years back that this would be > a useful thing to have, but I had no idea it was in the standard > libraries now. > > Anyway, while using it, I discovered a small omission from the Haskell > libraries: We have min, max, minimum and maximum. We also have minimumBy > and maximumBy. But there's no sign of minBy or maxBy. You can do, for > example, > > (min `on` postcode) customer1 customer2 > > but that gives you the lowest postcode, not the customer to which this > postcode belongs. By contrast, > > minimumBy (compare `on` postcode) [customer1, customer2] > > gives you the corresponding customer. But it seems silly to have to > actually construct a list just for this. So... is there any danger of > getting minBy and maxBy added? (I don't actually know off the top of my > head where min and max are defined - the Prelude?)
minBy and maxBy are already defined in Data.List - but they are local to minimumBy and maximumBy. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
