Mailing list for all users of the OCaml language and system.
 help / color / mirror / Atom feed
From: John Prevost <j.prevost@gmail.com>
To: Alex Baretta <alex@barettadeit.com>
Cc: Ocaml <caml-list@inria.fr>
Subject: Re: [Caml-list] Dummy polymorphic constructors
Date: Thu, 16 Dec 2004 17:38:46 -0500	[thread overview]
Message-ID: <d849ad2a041216143853ab054@mail.gmail.com> (raw)
In-Reply-To: <41C1E091.1040508@barettadeit.com>

On Thu, 16 Dec 2004 20:22:57 +0100, Alex Baretta <alex@barettadeit.com> wrote:
> Currently ocaml does not support empty polymorphic variant sum types.
> Say, I cannot write the following.
> 
> type empty = [ ]
> 
> This fails due to a syntax error rather than a typing error, which is a
> sensible, given that the type expression I have written is actually
> perfectly meaningful.

I'm somewhat confused as to why this is different from simply
declaring a new opaque type:

type empty

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.


  reply	other threads:[~2004-12-16 22:38 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 ` John Prevost [this message]
2004-12-17  7:42   ` [Caml-list] " Alex Baretta
2004-12-17  7:59   ` skaller
2004-12-17  1:10 ` Jacques Garrigue
2004-12-17  9:03   ` skaller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d849ad2a041216143853ab054@mail.gmail.com \
    --to=j.prevost@gmail.com \
    --cc=alex@barettadeit.com \
    --cc=caml-list@inria.fr \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox