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=ham
	autolearn_force=no version=3.4.4
X-Google-Thread: 103376,634259facc42df7a
X-Google-Attributes: gid103376,public
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news4.google.com!newsfeed2.dallas1.level3.net!news.level3.com!newsfeed-00.mathworks.com!news.tele.dk!feed118.news.tele.dk!news.tele.dk!small.news.tele.dk!proxad.net!cleanfeed1-b.proxad.net!nnrp2-2.free.fr!not-for-mail
Date: Thu, 06 Jul 2006 22:25:10 +0200
From: guillaume.portail@grospied.enanglais.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; fr-FR;
 rv:1.7) Gecko/20040616
X-Accept-Language: fr, en-us, en
MIME-Version: 1.0
Newsgroups: comp.lang.ada
Subject: Re: Conditional compilation of debug traces without cpp
References: <44aaae35$0$5389$626a54ce@news.free.fr>
 <mbdg8e.ddb.ln@hunter.axlog.fr> <44ac1562$0$10269$636a55ce@news.free.fr>
 <4ufi8e.ig7.ln@hunter.axlog.fr>
In-Reply-To: <4ufi8e.ig7.ln@hunter.axlog.fr>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
Message-ID: <44ad719c$0$5389$626a54ce@news.free.fr>
Organization: Guest of ProXad - France
NNTP-Posting-Date: 06 Jul 2006 22:25:00 MEST
NNTP-Posting-Host: 82.228.125.157
X-Trace: 1152217500 nnrp2-2.free.fr 5389 82.228.125.157:33603
X-Complaints-To: abuse@proxad.net
Xref: g2news2.google.com comp.lang.ada:5542
Date: 2006-07-06T22:25:00+02:00
List-Id: <comp.lang.ada>

Jean-Pierre Rosen wrote:

> Therefore yes, the *execution*  of the call will always involve the 
> *evaluation* of the parameters (unless the compiler can prove that this 
> evaluation has no side-effects - like a call to a function declared in a 
> pure package).

Ah yes, I just read LRM95-10.2.1(18), it seems to be what I want (I 
forgot this point). But Pure is applicable only to library units. And I 
need to apply it to functions of packages :

package Data is
   type T is private
   procedure ...
private
   type T is ...
end;

package Data.Image
   subtype T_String is String(...);
   function "+" (R : T) return T_String;
   ...
end;


- Data.Image."+" has really no side effect, but it cannot be declared 
Pure. Why ? The legality of such a pragma seems statically computable 
(the body of "+" should not access 'global' variables, etc).
- "+" is located in its own package, where UI resources are grouped, as 
to facilitate their potential elimination/counting (all are named 
*.*...*.Image).

--
Thierry Bernier