> for instance, Sets of Sets of things would be really nice. Sure. One could simply use lexicographic ordering (i. e. s1 `compare` s2 = setToList s1 `compare` setToList s2) or length-lexicographic ordering (for efficiency) ... = (cardinality s1, setToList s1) `compare` (cardinality s2, setToList s2)
As you write, there seems to be no reason not to do this. An Ord instance should be a linear ordering, and the above are. -- -- Johannes Waldmann ---- http://www.informatik.uni-leipzig.de/~joe/ -- -- [EMAIL PROTECTED] -- phone/fax (+49) 341 9732 204/252 -- _______________________________________________ Glasgow-haskell-users mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
