]> Jacques Garrigue wrote: >>>You cannot call m from other modules because you cannot create values >>>for the type "protector". >>> >>>Gerd >> >>Effective, definitely, but practical? Is this not supposed >>to be a feature of any general purpose object oriented language? > > > Actually, this seems perfectly practical. > If you have some good reason to "protect" a method, you can do it > cleanly. I would not call adding a fake type a clean solution. It's not idiomatic. A "protected" keyword is cleaner and easier to handle. Although it might be very tricky to implement in a language with type inference. > By the way, ocaml is not a general purpose object-oriented languages, > but a general purpose functional language with object-oriented > features. In particular, encapsulation is supported by the module > system rather than the class system. > Even in object-oriented languages, I've seen heated discussions on > whether using friend classes was good style or not. This is too big an issue for me. I only expressed the need I perceive for a construct to enable different instances of the same class to call methods on their siblings which are not visible to the general public. What I really want is a way to restrict through a type coercion the type of my "autofriendly" class. >>Anyway, for the meantime I'll keep the method public, and >>make sure I don't use it anywhere except where it makes >>sense, and I'll wait for some more insight from the developers. > > > Note that in many cases there are other ways to obtain the expected > behaviour. How about the following pseudocode? Is it sensible/viable? let module M : sig class type public = object <public_methods> end val make_public : unit -> public end = struct class type public = object <public_methods> end class protectd = object (self : #public) <public_methods> <protected_methods> end let make_public () -> (new protected :> public) end If this a working alternative, I would prefer over both the protector type and the protected keyword: clean, simple, and idiomatic. > For instance, if only one specific object is supposed to use a method, > you might register a private callback with it rather than the other > way round. > > Jacques Garrigue Hrmmm.... uuuhhh.... yes? What's it mean? Thank you very much, Jacques, for taking time to answer my former post. Alex ------------------- 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