]> YAMAGATA yoriyuki wrote: > From: Oleg <oleg_inconnu@myrealbox.com> > Subject: [Caml-list] Five Questions about Objects > Date: Sat, 13 Jul 2002 09:42:47 -0400 > > >>let point a b = >> object >> val x = a >> val y = b >> method get () = (x, y) >> end;; >> > > I think You can't do like this. object ... end is a part of a class > definition, and not an ordinary expression. > > However, I wonder why a class is necessary in the first place. I'm > not familiar with the theory of OOP, but I feel like direct creation > of objects is possible in functional languages. I think that the "class" and "class type" constructs are useful when expressing the relationship between types/classes. For example, "let point a b..." defines a function that creates an object. But, what does (x :> point) mean when point is a function instead of a class type? If anything, I would thing that (f :> g) would mean that the return type and parameter types of f follow the covariant/contravariant rules for methods. Similarly, what would the #point construct mean? Also, class types are types, and classes define implicit types, so I think that the class syntax should be close to the syntax for defining other kinds of types, instead of the syntax for defining functions. - Brian ------------------- 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