Date: Mon, 22 Sep 2003 10:06:02 +0200
From: Francois Pottier <francois.pottier at inria.fr>
To: lablgtk at kaba.or.jp
Subject: Re: Misc questions
Message-ID: <20030922100602.B31077 at pauillac.inria.fr>
Reply-To: Francois.Pottier at inria.fr
References: <20030921180318.A7068 at pauillac.inria.fr> <20030922101819Y.garrigue at kurims.kyoto-u.ac.jp> <20030922085521.A30725 at pauillac.inria.fr> <20030922165104L.garrigue at kurims.kyoto-u.ac.jp>
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In-Reply-To: <20030922165104L.garrigue at kurims.kyoto-u.ac.jp>; from garrigue at kurims.kyoto-u.ac.jp on Mon, Sep 22, 2003 at 04:51:04PM +0900


Hi Jacques,

On Mon, Sep 22, 2003 at 04:51:04PM +0900, Jacques Garrigue wrote:
> 
> OK. Gobject.obj is contravariant. Since for variants [`treemodel] is a
> subtype of [`treemodel|`liststore], then a (liststore obj) is a
> subtype of a (treemodel obj).

Hmm, I do see that

  [`treemodel|`liststore] obj   <:   [`treemodel] obj

is valid. But I still don't see why

  [`treemodel] obj   <:   tree_model obj

should be valid -- which was my original question :)

> You have to use ocamlbrowser to see all the contents directly.

Aah! I see. So browsing the .mli files by hand doesn't tell you all
of the truth. That is subtle.

-- 
François Pottier
Francois.Pottier@inria.fr
http://pauillac.inria.fr/~fpottier/