Please see below. On Oct 10, 2013, at 10:09 PM, Edward Kmett wrote:
> Wait, that sounds like it induces bad semantics. > > Can't we use that as yet another way to attack the sanctity of Set? > > class Ord a => Foo a where > badInsert :: a -> Set a -> Set a > > instance Foo Int where > badInsert = insert > > newtype Bar = Bar Int deriving (Eq,Foo) > > instance Ord Bar where > compare (Bar x) (Bar y) = compare y x > > Now you can badInsert into a Set. > > If that is still in play then even with all the roles machinery then GND > doesn't pass the restrictions of "SafeHaskell". =( Hrm. Yes. I'm out of fresh ideas at the moment. Maybe some will arrive with sleep. Richard _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
