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=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: border2.nntp.dca1.giganews.com!buffer2.nntp.dca1.giganews.com!border2.nntp.dca3.giganews.com!backlog4.nntp.dca3.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newspeer1.nac.net!feeder.erje.net!eu.feeder.erje.net!eternal-september.org!feeder.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: "J-P. Rosen" Newsgroups: comp.lang.ada Subject: Re: Style Question: normal record vs discriminated null-record. Date: Tue, 03 Jun 2014 06:40:16 +0200 Organization: A noiseless patient Spider Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Tue, 3 Jun 2014 04:40:16 +0000 (UTC) Injection-Info: mx05.eternal-september.org; posting-host="2b3884a634d8f846e0712b4e3a92507a"; logging-data="1711"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18OoXa1ihvLO98vI4jm04Tj" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 In-Reply-To: Cancel-Lock: sha1:8ejfyCsyW6MNt+QGz1sggZ2+VlU= X-Enigmail-Version: 1.6 X-Original-Bytes: 1911 Xref: number.nntp.dca.giganews.com comp.lang.ada:186711 Date: 2014-06-03T06:40:16+02:00 List-Id: Le 03/06/2014 06:38, J-P. Rosen a écrit : > Depends how you perceive your data. Discriminants are intended to define > some kind of subclasses of your type, and can be used to parameterized > inner components. Some criteria for you to chose: > > - You can define subtypes according to certain values of discriminants. > > - Discriminants are always initialized. > > - Discriminants cannot be changed after the declaration. > And I forgot: - You can have a private type whose discriminants are visible (and components private) -- J-P. Rosen Adalog 2 rue du Docteur Lombard, 92441 Issy-les-Moulineaux CEDEX Tel: +33 1 45 29 21 52, Fax: +33 1 45 29 25 00 http://www.adalog.fr