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[Caml-list] does class polymorphism need to be so complicated?
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Date: -- (:)
From: Richard Jones <rich@a...>
Subject: Re: [Caml-list] does class polymorphism need to be so complicated?
On Wed, Aug 20, 2003 at 11:05:35AM -0500, Brian Hurt wrote:
> Instead of declaring obj to be printable, why not just declare that it has 
> a function print?  Like:
> 
> class printer = 
>     object
>         method print (obj: <print: unit->unit>) = obj#print ();
>     end;;
> 
> This removes the need for a coercion, as it gets around the need to 
> upcast.

Interesting. Am I right in thinking that the <print : unit -> unit>
type syntax can refer to _any_ object which has a print method,
regardless of class hierarchy?

This could be quite a fun feature, although I'm not quite sure of the
best way to use it ...

Rich.

-- 
Richard Jones. http://www.annexia.org/ http://freshmeat.net/users/rwmj
Merjis Ltd. http://www.merjis.com/ - all your business data are belong to you.
'There is a joke about American engineers and French engineers. The
American team brings a prototype to the French team. The French team's
response is: "Well, it works fine in practice; but how will it hold up
in theory?"'

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