roconnor@theorem.ca wrote:
On Wed, 7 Jan 2009, Stefan Holdermans wrote:
Twan,
How about:
-- intended for |qualified| import |as Ord|: newtype Dual a = Dual { unDual :: a } deriving Eq
+1 for Dual.
+1 for Dual. The term seems common in lattice theory. I use it myself.
Dual does seem to be the right term, but I suggest using DualOrd or DualOrdering instead. The fact that it can be imported qualified is no reason to confuse people, in many cases the function will not be imported qualified, since conflicts are very unlikely. To me just "dual" does not immediatly suggest a reverse ordering. Consider also: sortBy (comparing `on` Dual . fst) stuff vs. sortBy (comparing `on` DualOrd . fst) stuff In the first version it is not immediatly clear that dual has something to do with the ordering, and not just taking some kind of dual of something in some other way. Also, the record selector should be called getDual{Ord}, in accordance with the monoid wrappers and mtl types. In summary, I like: DualOrd{ering}, ReverseOrd{ering} and am okay with Desc{ending}. Twan