Re: [Caml-list] Re: Define class and sum type in one time

[Guillaume Yziquel <guillaume.yziquel@citycable.ch>]

Le Thursday 17 Mar 2011 à 11:50:37 (+0100), Pierre-Alexandre Voye a écrit :
>    So, this is impossible  ?   :
>    class maclasse = object(self)
>    Â  val mutable valeur = (None : truc option)
>    Â  method getValeur = valeur
>    end
>    and
>    truc = Machin of (maclasse->int) | Recur of truc;;
>    ?
>    (three attempt to write a correct example of my problem.. All apologies
>    !)

No, you can. Break the recursivity with a recursive module. However,
it's quite clumsy, so if you do not have a compelling reason to use
object, avoid the useless complexity.

module rec M : sig

	class maclasse : object

		val mutable valeur : M.truc option 

		method getValeur : M.truc option

	end

	type truc = Machin of (maclasse -> int) | Recur of truc

end = struct

	class maclasse = object

		val mutable valeur : M.truc option = None

		method getValeur = valeur

	end

	type truc = Machin of (maclasse -> int) | Recur of truc

end

include M

-- 
     Guillaume Yziquel