From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <lukstafi@gmail.com>
Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83])
	by yquem.inria.fr (Postfix) with ESMTP id 5BBE7BBAF
	for <caml-list@yquem.inria.fr>; Sun,  5 Dec 2010 09:25:56 +0100 (CET)
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: Ar0AAGfb+kzRVdg0kGdsb2JhbACjKggVAQEBAQkJDAcRBB6lAolpghmEBS6IVgEBAwWFRASKboYF
X-IronPort-AV: E=Sophos;i="4.59,301,1288566000"; 
   d="scan'208";a="83107519"
Received: from mail-qw0-f52.google.com ([209.85.216.52])
  by mail2-smtp-roc.national.inria.fr with ESMTP; 05 Dec 2010 09:25:55 +0100
Received: by qwe4 with SMTP id 4so5389231qwe.39
        for <caml-list@yquem.inria.fr>; Sun, 05 Dec 2010 00:25:55 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=gamma;
        h=domainkey-signature:received:mime-version:received:in-reply-to
         :references:from:date:message-id:subject:to:cc:content-type
         :content-transfer-encoding;
        bh=eQPabo3XL+zx++tjIcl/2nhpC4W7+fPYCxmvcxXViQg=;
        b=M9IezANB0DCYxB5ja9YaqqmKcw/IcQwu6zYjAbVV/6yhB5aOZdDIQicN88xgy2qrey
         R9vjUu+5As8s91xAwSmfD0uAmFf/Q5RQ6USTdL03LK6LAWzzWLXywMj4gbZEC3tKfXpk
         xcJ9K0GKsqDCNLZmxXvjDgSw9DheNzsymxfKQ=
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:from:date:message-id:subject:to
         :cc:content-type:content-transfer-encoding;
        b=rGdpU3aWy73MORSuBaC2YYUzWVZFVfYuAdrZTo73xWptFQj+l93YczKVwWGu+ns4Dx
         5Awac/9D87/ABp5U7f3Tq/RrI41oPARhsCGXZ1t5ikohDTzhk5uCZhYrjYLfcXecF1FZ
         wge4eL7Rn/ZPEI4O9B4aqLOfwMwvgkeyc3KX8=
Received: by 10.229.183.135 with SMTP id cg7mr3012286qcb.296.1291537555294;
 Sun, 05 Dec 2010 00:25:55 -0800 (PST)
MIME-Version: 1.0
Received: by 10.229.230.149 with HTTP; Sun, 5 Dec 2010 00:25:35 -0800 (PST)
In-Reply-To: <AANLkTinVSDB-XWXKvJPxDzhzxox-Vmxnw9Lw2ucLy0De@mail.gmail.com>
References: <AANLkTimVTv7J_b6AY1gKKT9hdQx83a+4FBM7pqvHpAHM@mail.gmail.com>
 <AANLkTimmAMG_1+UhNh+Q8bR22XsDtoF44gDd7YEwx5v+@mail.gmail.com>
 <AANLkTim5uyeAXwSzvsVtDyQi28kqdKfE2hDOeCnRW+4Z@mail.gmail.com>
 <AANLkTi=brs65VkfeM0qt+fLFVd=Vc7PMm809VstVN=Q-@mail.gmail.com>
 <AANLkTin9Bdea8CZjx3OR1NsFFawSu7G8KGD_ZiTvGr1S@mail.gmail.com>
 <AANLkTimRki9EfbN0ekQQA2RmaQ2u28pHuvy37-eLhtxq@mail.gmail.com>
 <AANLkTi=tXmna=Rk5nyQbYWNambBYUUk1=nRS=aGC0cfV@mail.gmail.com> <AANLkTinVSDB-XWXKvJPxDzhzxox-Vmxnw9Lw2ucLy0De@mail.gmail.com>
From: Lukasz Stafiniak <lukstafi@gmail.com>
Date: Sun, 5 Dec 2010 09:25:35 +0100
Message-ID: <AANLkTi=uB6NJ94yK63iDHopzCsbd_byvb2WKPM5KvvvU@mail.gmail.com>
Subject: Re: [Caml-list] GADT constructor syntax
To: Jacques Le Normand <rathereasy@gmail.com>
Cc: caml-list caml-list <caml-list@yquem.inria.fr>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
X-Spam: no; 0.00; lukasz:01 syntax:01 lukasz:01 quantified:01 notation:01 existential:01 wrote:01 caml-list:01 constructor:01 exceptions:01 int:01 int:01 explicitly:02 variables:02 pattern:04 

On Sun, Dec 5, 2010 at 9:10 AM, Lukasz Stafiniak <lukstafi@gmail.com> wrote=
:
>
> shouldn't mean that Embed is "basically" Embed of int : int term. My
> position is that if a type variable should be treated as local to a
> branch, it should be explicitly quantified (using the dot notation,
> for example "Ignore of 'a. 'a : int term", without any exceptions to
> "existential" variables). And that the patterns
>
> type X =3D
> =A0| Branch of Y
>
> and
>
> type X =3D
> =A0| Branch of Y : X
>
> should be equivalent (where X could for example be 'a term).

To clarify again: modulo variable capture! That is, the pattern

> type X =3D
> =A0| Branch of 'a. Y : X

will be different (unless 'a is not used in Y nor X).