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Date: Wed, 20 Aug 2003 11:05:35 -0500 (CDT)
From: Brian Hurt <bhurt@spnz.org>
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To: Benjamin Geer <ben@socialtools.net>
cc: <caml-list@inria.fr>
Subject: Re: [Caml-list] does class polymorphism need to be so complicated?
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On Wed, 20 Aug 2003, Benjamin Geer wrote:

> class printer =
>    object
>      method print (obj : printable) = obj#print()
>    end ;;

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.

Brian


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