]> Le 9 oct. 09 à 07:25, rouanvd@softwarerealisations.com a écrit : > ====================================================== > type t = MyInt of int | MyFloat of float | MyString of string ;; > > let foo printerf = function > | MyInt i -> printerf string_of_int i > | MyFloat x -> printerf string_of_float x > | MyString s -> printerf (fun x -> x) s > ;; > ====================================================== > I read that there are lots of workarounds for the above code > snippet, but > I would like to > Know why this code fails and what is the best workaround for this > type of > code. You might find some answers here: http://caml.inria.fr/pub/old_caml_site/FAQ/FAQ_EXPERT-eng.html#arguments_polymorphes Though this won't clearly tell you "why", and I sadly don't know the answer. From my experience the type system limitations are not so big hindrance in practice, you may have to work a bit to get what you want fit in the type system, but I've never found a thing that wouldn't work at all. BTW: > I have done the same thing in Haskell and it correctly infers the > type of > foo. It doesn't work for me with ghc 6.10.3. I mean, unless you provided the Haskell compiler with some type annotations the same error occurs. But I am not a haskell expert so I may be wrong. V.