From: Stephane Glondu <Stephane.Glondu@crans.org>
To: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Object typing
Date: Sun, 10 Jul 2005 11:25:59 -0700 [thread overview]
Message-ID: <200507101126.00725.Stephane.Glondu@crans.org> (raw)
In-Reply-To: <42D063EC.3040900@earthlink.net>
On Saturday 09 July 2005 16:55, Matthew O'Connor wrote:
> Here is a version of what I would like to be able to do, but can't or
> don't know how. I would like to use polymorphic variants to enable
> easier extensibility of the hierarchy.
>
> [...]
>
> I'm at a loss as how to proceed. Any other suggestions or ideas or
> better solutions would be greatly appreciated. Thank you.
How about:
(* test.ml *)
class ['a] entity =
object
method is_a (v : 'a) =
if v = `Entity then true
else false
end
class ['a] predator =
object
inherit ['a] entity as super
method is_a v =
if v = `Predator then true
else super#is_a v
end
let ent = new predator;;
ent#is_a `Predator;; (* returns true *)
ent#is_a `Entity;; (* returns true *)
ent#is_a `Chicken;; (* returns false *)
Stephane Glondu.
next prev parent reply other threads:[~2005-07-10 18:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-07-09 23:55 Matthew O'Connor
2005-07-10 0:20 ` [Caml-list] " Pietro Abate
2005-07-10 6:19 ` Matthew O'Connor
2005-07-10 18:25 ` Stephane Glondu [this message]
2005-07-10 22:06 ` Christophe TROESTLER
2005-07-11 6:23 ` Matthew O'Connor
2005-07-11 7:18 ` Remi Vanicat
2005-07-11 8:22 ` Jacques Garrigue
2005-07-11 9:16 ` Marcin 'Qrczak' Kowalczyk
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