From: Alex Baretta <alex@barettadeit.com>
To: Ocaml <caml-list@inria.fr>
Subject: Re: [Caml-list] Dummy polymorphic constructors
Date: Fri, 17 Dec 2004 08:42:03 +0100 [thread overview]
Message-ID: <41C28DCB.3050409@barettadeit.com> (raw)
In-Reply-To: <d849ad2a041216143853ab054@mail.gmail.com>
John Prevost wrote:
>>type empty = [ ]
>
> I'm somewhat confused as to why this is different from simply
> declaring a new opaque type:
>
> type empty
Ah, this is interesting!
> Since there is no way to construct a value of the type, nor any way to
> deconstruct such a value, how is it different?
>
> John.
>
Not much, actually. I thought opaque types could only be *declared*.
module M : sig type t end = struct type t = *** end
I never realized that a type could be *defined* as opaque.
module M = struct type t end
Alex
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next prev parent reply other threads:[~2004-12-17 7:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-12-16 19:22 Alex Baretta
2004-12-16 22:38 ` [Caml-list] " John Prevost
2004-12-17 7:42 ` Alex Baretta [this message]
2004-12-17 7:59 ` skaller
2004-12-17 1:10 ` Jacques Garrigue
2004-12-17 9:03 ` skaller
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