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=-0.3 required=5.0 tests=BAYES_00,
	REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4
X-Google-Thread: 103376,5cd2177597e1920b
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!newsfeed00.sul.t-online.de!newsfeed01.sul.t-online.de!t-online.de!news.belwue.de!newsfeed.ision.net!newsfeed2.easynews.net!ision!newsfeed.arcor.de!newsspool1.arcor-online.net!news.arcor.de.POSTED!not-for-mail
From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Subject: Re: discriminants, what are they?
Newsgroups: comp.lang.ada
User-Agent: 40tude_Dialog/2.0.15.1
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Reply-To: mailbox@dmitry-kazakov.de
Organization: cbb software GmbH
References: <1166399856.146825.149540@f1g2000cwa.googlegroups.com>
 <wccy7p69h60.fsf@shell01.TheWorld.com>
Date: Mon, 18 Dec 2006 11:23:50 +0100
Message-ID: <aa0svfsddwez.8bzbv0bpcovf.dlg@40tude.net>
NNTP-Posting-Date: 18 Dec 2006 11:23:47 CET
NNTP-Posting-Host: a908f8eb.newsspool1.arcor-online.net
X-Trace: 
 DXC=en_7CFJo8Xcg`45cDR8l?oic==]BZ:afn4Fo<]lROoRa^YC2XCjHcbiGYX3fBd>A4`DNcfSJ;bb[eIRnRBaCd<Mn`11jF8nGF;lbG<4QO\Qh>l
X-Complaints-To: usenet-abuse@arcor.de
Xref: g2news2.google.com comp.lang.ada:7942
Date: 2006-12-18T11:23:47+01:00
List-Id: <comp.lang.ada>

On Sun, 17 Dec 2006 19:33:27 -0500, Robert A Duff wrote:

> "markww" <markww@gmail.com> writes:
> 
>> Can explain what an Ada discriminant is? I found this definition but
> 
> It's a parameter that can be passed to a type when making an object of
> the type, sort of like a parameter passed to a procedure when making a
> call to that procedure.  It can be used inside the type to determine which
> variant you want, or the bounds of an array, or to pass further along to
> another discriminant of a component type, or in an expression that
> initializes a component.
> 
> Another view: it's a constant component.  Once you give a discriminant
> of a particular object a value, that value cannot change.

and with a subtype declaration some of the discriminants can be fixed to
distinct values, e.g. to produce "specializations."

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de