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,c9d5fc258548b22a
X-Google-NewGroupId: yes
X-Google-Attributes: gida07f3367d7,domainid0,public,usenet
X-Google-Language: ENGLISH,ASCII-7-bit
Path: 
 g2news2.google.com!news3.google.com!proxad.net!feeder1-2.proxad.net!weretis.net!feeder4.news.weretis.net!news1.tnib.de!feed.news.tnib.de!news.tnib.de!newsfeed.freenet.ag!news.netcologne.de!ramfeed1.netcologne.de!newsfeed.arcor.de!newsspool3.arcor-online.net!news.arcor.de.POSTED!not-for-mail
Date: Mon, 07 Feb 2011 18:55:09 +0100
From: Georg Bauhaus <rm.dash-bauhaus@futureapps.de>
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US;
 rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7
MIME-Version: 1.0
Newsgroups: comp.lang.ada
Subject: Re: How do I write directly to a memory address?
References: 
 <67063a5b-f588-45ea-bf22-ca4ba0196ee6@l11g2000yqb.googlegroups.com>
 <31c357bd-c8dc-4583-a454-86d9c579e5f4@m13g2000yqb.googlegroups.com>
 <05a3673e-fb97-449c-94ed-1139eb085c32@x1g2000yqb.googlegroups.com>
 <iimmvm$tsp$1@news.eternal-september.org> <8r86vgFc3uU1@mid.individual.net>
 <iimrem$udn$1@news.eternal-september.org>
 <19fh1chm74f9.11cws0j5bckze.dlg@40tude.net>
 <fa33fca1-c95b-4558-8a4c-7b3276366ffc@m13g2000yqb.googlegroups.com>
 <4d4ff70e$0$6886$9b4e6d93@newsspool2.arcor-online.net>
 <737a6396-72bd-4a1e-8895-7d50f287960e@d28g2000yqc.googlegroups.com>
 <4d5008a5$0$6879$9b4e6d93@newsspool2.arcor-online.net>
 <eda00084-fcc3-416c-bd3e-8b9e9c1a4b40@o13g2000yql.googlegroups.com>
In-Reply-To: 
 <eda00084-fcc3-416c-bd3e-8b9e9c1a4b40@o13g2000yql.googlegroups.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Message-ID: <4d5031fe$0$6765$9b4e6d93@newsspool3.arcor-online.net>
Organization: Arcor
NNTP-Posting-Date: 07 Feb 2011 18:55:10 CET
NNTP-Posting-Host: 1d2d17cb.newsspool3.arcor-online.net
X-Trace: 
 DXC=ieJYB@OCK5UHigV@eW57PQMcF=Q^Z^V3X4Fo<]lROoRQ8kF<OcfhCO[NnY[\SNbC7Xnc\616M64>ZLh>_cHTX3j]<:ZMX6gD_n\
X-Complaints-To: usenet-abuse@arcor.de
Xref: g2news2.google.com comp.lang.ada:17912
Date: 2011-02-07T18:55:10+01:00
List-Id: <comp.lang.ada>

On 07.02.11 17:54, Ludovic Brenta wrote:
> Georg Bauhaus wrote:
>> Exactly.  Style has, by hypothesis, a strong impact on on code
>> quality [...]
> 
> I would rephrase that as: style has, *in my experience*, a strong
> impact on code quality.

That's something from which to start an investigation.

> You can always program dangerously in Ada but you have to be explicit
> about it.

Yes.


> The generator is not modified; its associated (pointed-to) state is.

The state is "its" state; the LRM does not seem to mention
a pointer.  GNAT uses a limited record with no pointers in
it, but does refer to components through non-standard
'Unrestricted_Access inside the function.

GNAT: "
   --  The design of this spec is very awkward, as a result of Ada 95 not
   --  permitting in-out parameters for function formals (most naturally
   --  Generator values would be passed this way). "

I think it is fair to say that (a) Random modifies the generator's
state and that (b) the specification does not reflect that Random
acts as this state changing subprogram.




> Well, I came to wonder what intentions are conveyed by "void foo (int
> arg)" and why modifying arg inside foo could be intentional.  Since I
> came up with no convincing reason (the only reasons being variants of
> premature optimization), I concluded that the possibility of "void foo
> (int arg)" as opposed to "void foo (const int arg)" was a flaw in the
> C language, that cost me a lot of effort.

Ease of implementation when pushing parameters?


void foo(int countdown)
{
  while (--countdown) {
    fputc('.', stdout);
  }
  fputc('\n', stdout);
}