From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,ae9506fd4dcf7090
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-10-22 22:22:03 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!news.tele.dk!news.tele.dk!small.news.tele.dk!fr.usenet-edu.net!usenet-edu.net!enst.fr!not-for-mail
From: "Grein, Christoph" <christoph.grein@eurocopter.com>
Newsgroups: comp.lang.ada
Subject: Re: Concatenation and Characters
Date: Wed, 23 Oct 2002 07:15:59 +0200 (MET DST)
Organization: ENST, France
Sender: comp.lang.ada-admin@ada.eu.org
Message-ID: <mailman.1035350522.7202.comp.lang.ada@ada.eu.org>
Reply-To: comp.lang.ada@ada.eu.org
NNTP-Posting-Host: marvin.enst.fr
Mime-Version: 1.0
Content-Type: TEXT/plain; charset=us-ascii
X-Trace: avanie.enst.fr 1035350522 45344 137.194.161.2 (23 Oct 2002 05:22:02
 GMT)
X-Complaints-To: usenet@enst.fr
NNTP-Posting-Date: Wed, 23 Oct 2002 05:22:02 +0000 (UTC)
Return-Path: <christoph.grein@eurocopter.com>
X-Authentication-Warning: mail.eurocopter.com: uucp set sender to
 <christoph.grein@eurocopter.com> using -f
Content-MD5: SEgv1NX2/2TQ+dJiFUEvqQ==
X-Mailer: dtmail 1.2.1 CDE Version 1.2.1 SunOS 5.6 sun4u sparc 
Errors-To: comp.lang.ada-admin@ada.eu.org
X-BeenThere: comp.lang.ada@ada.eu.org
X-Mailman-Version: 2.0.13
Precedence: bulk
X-Reply-To: "Grein, Christoph" <christoph.grein@eurocopter.com>
List-Unsubscribe: <http://ada.eu.org/mailman/listinfo/comp.lang.ada>,
	<mailto:comp.lang.ada-request@ada.eu.org?subject=unsubscribe>
List-Id: comp.lang.ada mail<->news gateway <comp.lang.ada.ada.eu.org>
List-Post: <mailto:comp.lang.ada@ada.eu.org>
List-Help: <mailto:comp.lang.ada-request@ada.eu.org?subject=help>
List-Subscribe: <http://ada.eu.org/mailman/listinfo/comp.lang.ada>,
	<mailto:comp.lang.ada-request@ada.eu.org?subject=subscribe>
Errors-To: comp.lang.ada-admin@ada.eu.org
X-BeenThere: comp.lang.ada@ada.eu.org
Xref: archiver1.google.com comp.lang.ada:30057
Date: 2002-10-23T07:15:59+02:00

> It really is a language design flaw that you can't have a zero-length
> positional aggregate.

with Ada.Text_IO;
use  Ada.Text_IO;

procedure Xxx is

  type Empty is range 1 .. 0;
  type Array_Type is array (Positive range <>) of Empty;

  function F return Array_Type is
  begin
    return (5 .. 4 => 0);
  end;

  Nothing: Array_Type := F;

begin

  Put_Line (Boolean'Image (Nothing = (7..4 => Empty'First)));
  Put_Line (Boolean'Image (Nothing = (0..-1 => Empty'Last)));

end Xxx;


try to run this. No value can fulfil the range constraint of Empty, but it does 
not matter, since the range is empty and the value is not evaluated.

(I'm not so sure that the range 0..-1 is legal, but my compiler accepts it and 
prints True twice, and I 
just do not feel like searching the RM :-(