Hello Cristiano, Wednesday, January 13, 2010, 9:43:06 PM, you wrote:
coming up to my mind is that type inference actually forbids a type-directed resolution of names as in C++ or Java.
you are right. we either have ad-hoc polymorphism like in C++ where type of id selected based on type of arguments, like in int open(char *s) int open(int i) or two-way type inference where each id has just one type. otherwise, having both overloaded ids and two-way inference, we will got polynomial raise of complexity of type inferencing. ie. imagine some f = a . b . c . d where a,b,c,d have multiple possible types there is backdorr to this mechanism - you can define foo inside of class. moreover, you can use this to overload struct fields: class HasFoo a b where foo :: a -> b data X = {fooX :: Int} data Y = {fooY :: Char} instance HasFoo X Int where foo=fooX instance HasFoo Y Char where foo=fooY although error messages may be not ideal ;) -- Best regards, Bulat mailto:Bulat.Ziganshin@gmail.com