Message-ID: <3EB64B7F.4040604 at lix.polytechnique.fr>
Date: Mon, 05 May 2003 13:31:11 +0200
From: Benjamin Monate <benjamin.monate at lix.polytechnique.fr>
MIME-Version: 1.0
To: Richard Jones <rich at annexia.org>
Cc: lablgtk at kaba.or.jp
Subject: Re: More GtkHtml questions
References: <20030503100346.GE24136 at redhat.com> <16051.59001.830936.263287 at karryall.dnsalias.org> <20030504141338.GA9710 at redhat.com> <20030505095109.GA10796 at redhat.com> <16054.16579.173448.942063 at akasha.ijm.jussieu.fr> <20030505110949.GB10796 at redhat.com>
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Richard Jones wrote:

>  
>
>I'm not sure exactly what the difference is between:
>
>method cut = cut obj
>
>and
>
>method cut () = cut obj
>
>Doesn't the first define a partial function requiring one additional
>argument (the unit) before it is called?
>  
>

No.
In the first case:
let x = o#cut in...
x has the same type as "cut obj".

In the second case,
let x= o#cut in ...
 x has type unit -> type of "cut obj".
In this case you may use directly x#cut as an argument to a callback.

In lablgtk, methods having side effects always have an extra unit 
argument as explained in the README.


>I have another question. I've defined a "font_style" type as:
>...
>Of course in Caml these are variants, not just integers, so you can't
>do logical operations on them. I'm not sure if there's an easy way to
>solve this in Caml - except by having some C native functions for
>converting font_style to integers and/or performing logical
>operations.  This doesn't seem type safe to me. Do you have any
>opinions on the best way to solve this?
>
In lablgtk, we use lists to denote disj/cunjunctions.
You may provide something like :
val set_font_style : html -> ~enable:font_style list -> ~keep:font_style 
list -> unit

Cheers
Benjamin