Twan van Laarhoven wrote:
-- Proposal--
Ticket: #2659 (for sortOn and friends) Ticket: #2660 (for Down newtype) Deadline: now+2 weeks = 2008-10-20
Questions: 1. should sortOn be added to Data.List? 2. should all other *On functions be added as well? 3. what name should these functions get? 4. should the sortOn' variations be added? What about the naming? 5. should Down be added to Data.Ord?
-1 concerning sortOn and friends I think that sortBy (comparing f) is a very good and modular name for the functionality intended, no need to create another one. The only advantage of a special sortOn function would be that you can document it, i.e. there's no haddock blurb for sortBy (comparing f) . Hm, though sortOn could be useful if it caches the values of f by default, like the sortOn' proposed. But Jean-Philippe's code is a beautiful solution for this situation. +1 concerning Down, but I don't like the name. In particular I don't like the "get" prefix in "getDown". I'd simply use newtype Desc a = Desc a without label or fromDesc if really necessary. Regards, apfelmus