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From: =?UTF-8?Q?Fran=c3=a7ois_Pottier?= <francois.pottier@inria.fr>
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Date: Fri, 13 Jan 2017 10:09:06 +0100
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Subject: [Caml-list] How to indicate that I am overriding an inherited
 virtual method?


Dear OCaml users,

Is there an OCaml equivalent of Java's @Override keyword, which allows
indicating that a method definition is intended to override an inherited
(virtual or concrete) method?

As far as I can see, in OCaml, the "method!" form works for inherited 
concrete
methods:

   class base = object
     method foo: string = "uh?"
   end

   class child = object
     inherit base
     method! foo = "ha!"
       (* OK *)
   end

but does not work for inherited virtual methods:

   class virtual base = object
     method virtual foo: string
   end

   class child = object
     inherit base
     method! foo = "ha!"
       (* Error: The method `foo' has no previous definition *)
   end

Is this intentional?

This is too bad. I seem to be forced to use "method" instead of "method!".
Therefore, I cannot indicate my intent, and if I mistype the name "foo" in
the definition of the child class, the compiler cannot catch this mistake.
(Well, in this case, it can, as the child class is not declared virtual.)

--
François Pottier
francois.pottier@inria.fr
http://gallium.inria.fr/~fpottier/