On 2011-07-29, at 11:22 AM, Brandon Allbery wrote:
Ask yourself this: is True *every* instance of Ord? You are expecting it to be an "any", but it's an "every" (forall).
By the way, True happens to be an instance of Ord but it doesn't have to be. You're working backwards here, I think. It happens that useful operations on things in class Ord generally produce Bool; that doesn't mean Bool must be Ord.
Right - actually, I did not expect it to compile. I gave the code as, perhaps, a counterexample to what some other responses seemed to be asserting, although it is possible I did not get their point(s) correctly. They seemed to say that adding a constraint is of itself what makes the cases that used numeric literals work. But it seems (as described in Brent Yorgey's post) that there is more to it than that. - J -