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=-2.9 required=5.0 tests=BAYES_00,MAILING_LIST_MULTI
	autolearn=unavailable autolearn_force=no version=3.4.4
X-Google-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,c62c9a290ae8e9ab
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2001-02-15 02:10:06 PST
Path: 
 supernews.google.com!sn-xit-03!supernews.com!nntp.cs.ubc.ca!freenix!enst!enst.fr!not-for-mail
From: Mario Amado Alves <maa@di.fct.unl.pt>
Newsgroups: comp.lang.ada
Subject: Re: [Ada-Comment] Extensible Enumerated Types
Date: Thu, 15 Feb 2001 10:13:15 +0000 (WET)
Organization: ENST, France
Sender: comp.lang.ada-admin@ada.eu.org
Message-ID: <mailman.982231753.2811.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 982231753 24877 137.194.161.2 (15 Feb 2001 10:09:13
 GMT)
X-Complaints-To: usenet@enst.fr
NNTP-Posting-Date: Thu, 15 Feb 2001 10:09:13 +0000 (UTC)
To: comp.lang.ada@ada.eu.org
Return-Path: <maa@di.fct.unl.pt>
X-Authentication-Warning: lexis.di.fct.unl.pt: maa owned process doing -bs
In-Reply-To: <3A8A70EC.27658CC9@earthlink.net>
Errors-To: comp.lang.ada-admin@ada.eu.org
X-BeenThere: comp.lang.ada@ada.eu.org
X-Mailman-Version: 2.0
Precedence: bulk
List-Help: <mailto:comp.lang.ada-request@ada.eu.org?subject=help>
List-Post: <mailto:comp.lang.ada@ada.eu.org>
List-Subscribe: <http://ada.eu.org/mailman/listinfo/comp.lang.ada>,
	<mailto: comp.lang.ada-request@ada.eu.org?subject=subscribe>
List-Id: comp.lang.ada mail<->news gateway <comp.lang.ada.ada.eu.org>
List-Unsubscribe: <http://ada.eu.org/mailman/listinfo/comp.lang.ada>,
	<mailto: comp.lang.ada-request@ada.eu.org?subject=unsubscribe>
List-Archive: <http://ada.eu.org/pipermail/comp.lang.ada/>
Errors-To: comp.lang.ada-admin@ada.eu.org
X-BeenThere: comp.lang.ada@ada.eu.org
Xref: supernews.google.com comp.lang.ada:5268
Date: 2001-02-15T10:13:15+00:00

A provisional implementation is to make

  type T is {A, B, C};
  type Extended_T is new T with {X, Y, Z};

merely syntactic sugar for

  type T is {A, B, C}
  type Extended_T is {A, B, C, X, Y, Z};

Of course there is no proper derivation here. Nevertheless it seems like a
useful construct. I often miss it.

| |,| | | |RuaFranciscoTaborda24RcD 2815-249CharnecaCaparica 351+939354005
|M|A|R|I|O|
|A|M|A|D|O|DepartmentoDeInformaticaFCT/UNL 2825-114 Caparica 351+212958536
|A|L|V|E|S|                                                  fax 212948541
| | | | | |                 maa@di.fct.unl.pt                FCT 212948300