]> Here's a working solution, I think. let raw_min = min let raw_max = max let nan_or_equal x y = not (x < y) && not (x > y) (** min and max that choose nan if its there *) let min x y = if x = y then x else if nan_or_equal x y then nan else raw_min x y let max x y = if x = y then x else if nan_or_equal x y then nan else raw_max x y > min and max have pretty strange behavior when it comes to nan's. Here's > an example: > > # min 3. nan;; > - : float = 3. > # min nan 3.;; > - : float = nan > > When you think about it, the reason for this is clear. comparisons > involving nan's always return false, so if you simply implement min as > follows: > > if x < y then x else y > > the the result will depend on the order. > > Now here's the weird bit. I decided I wanted a polymorphic comparison > that wouldn't have this problem. But this is a little harder than it > seems, since it turns out that specialized float version of equality is > different from the polymorphic version. Here's the example: > > # let raw_min = min > val raw_min : 'a -> 'a -> 'a = <fun> > # let min x y = > if not (y = y) then y > else if not (x = x) then x > else raw_min x y > ;; > val min : 'a -> 'a -> 'a = <fun> > # let fmin (x:float) y = > if not (y = y) then y > else if not (x = x) then x > else raw_min x y > ;; > val fmin : float -> float -> float = <fun> > # fmin 3. nan;; > - : float = nan > # fmin nan 3.;; > - : float = nan > # min nan 3.;; > - : float = nan > # min 3. nan;; > - : float = 3. > > So, does this count as a bug? Any ideas about how to fix this behavior in > a reasonably efficient way? > > Yaron > > ------------------- > To unsubscribe, mail caml-list-request@inria.fr Archives: > http://caml.inria.fr > Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: > http://caml.inria.fr/FAQ/ > Beginner's list: http://groups.yahoo.com/group/ocaml_beginners > ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners