From: Martin Jambon <martin.jambon@ens-lyon.org>
To: Goswin von Brederlow <goswin-v-b@web.de>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Bug? Constraints get ignored in methods
Date: Wed, 01 Apr 2009 01:12:50 +0200 [thread overview]
Message-ID: <49D2A372.3010800@ens-lyon.org> (raw)
In-Reply-To: <49D2A0AF.1080300@ens-lyon.org>
Martin Jambon wrote:
> Use a classic list:
>
>
> class base = ...
> class derived = ... (* inherits base *)
>
> type obj = Base of base | Derived of derived
>
> let obj_list = [ Base (new base); Derived (new derived); ... ]
>
> let iter_base f l =
> List.iter (function Base x -> f x | Derived x -> f (x :> base)) l
>
> let iter_derived f l =
> List.iter (function Derived x -> f x | Base _ -> ()) l
>
> ...
Or simply one list per type, each list containing all the elements compatible
with the type.
I would stay away from any solution that requires special methods in order to
solve the polymorphism/heterogeneity problem. Keep the modifications non-invasive.
Cheers,
Martin
--
http://mjambon.com/
next prev parent reply other threads:[~2009-03-31 23:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-31 22:05 Goswin von Brederlow
2009-03-31 23:01 ` [Caml-list] " Martin Jambon
2009-03-31 23:12 ` Martin Jambon [this message]
2009-03-31 23:52 ` Goswin von Brederlow
2009-04-01 0:08 ` Goswin von Brederlow
2009-04-01 11:41 ` Martin Jambon
2009-04-01 15:57 ` Goswin von Brederlow
2009-04-01 18:45 ` Martin Jambon
2009-04-01 1:24 ` Peng Zang
2009-04-01 3:25 ` Goswin von Brederlow
2009-04-02 8:39 ` Jacques GARRIGUE
2009-04-03 20:53 ` Goswin von Brederlow
2009-04-06 4:30 ` Jacques Garrigue
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