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-Language: ENGLISH,ASCII-7-bit
X-Google-Thread: 103376,ae9506fd4dcf7090
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2002-10-22 07:46:12 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!paloalto-snf1.gtei.net!news.gtei.net!enews.sgi.com!nntp1.phx1.gblx.net!nntp.gblx.net!nntp.gblx.net!newsfeed.news2me.com!sn-xit-05!sn-xit-01!sn-post-01!supernews.com!corp.supernews.com!not-for-mail
From: "Matthew Heaney" <mheaney@on2.com>
Newsgroups: comp.lang.ada
Subject: Re: Concatenation and Characters
Date: Tue, 22 Oct 2002 10:45:58 -0400
Organization: Posted via Supernews, http://www.supernews.com
Message-ID: <urap57ajqc4rc5@corp.supernews.com>
References: <ysgp9.714$_u6.401@nwrddc01.gnilink.net>
 <slrnaqb570.c68.randhol+news@kiuk0152.chembio.ntnu.no>
 <aGgp9.52608$Oa1.8791@nwrddc02.gnilink.net>
 <slrnaqb6p8.cq7.randhol+news@kiuk0152.chembio.ntnu.no>
 <44hp9.807$_u6.205@nwrddc01.gnilink.net> <3DA5AE5F.3030902@attbi.com>
 <3DB03EF1.EE771923@mmm.com> <ap15v2$i85$2@a1-hrz.uni-duisburg.de>
 <3DB43EB0.AAF4B38C@mmm.com> <3DB44B9C.80007@worldnet.att.net>
 <3DB466CB.7CE0BC59@mmm.com> <3DB4AD20.4070109@acm.org>
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2720.3000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
X-Complaints-To: abuse@supernews.com
Xref: archiver1.google.com comp.lang.ada:30032
Date: 2002-10-22T10:45:58-04:00
List-Id: <comp.lang.ada>


"Jeffrey Carter" <jrcarter@acm.org> wrote in message
news:3DB4AD20.4070109@acm.org...
>
> All correct implementations of Ada must compile and execute this
> program. Ada does not require default initialization of variables except
> for access variables, if we limit ourselves to elementary types. Ada
> does not require that compilers detect references to uninitialized
> variables. Ada does not require that references to uninitialized
> variables be detected at run time.

This isn't quite right.  If an object of a discrete type is used to index an
array, the compiler is required to ensure that the object --even if
uninitialized-- is only used to index an actual component of the array
object.

For example:

procedure Op (S : String) is
  I : Positive;
begin
  S (I) := 'x';
end;

The Ada95 language guarantees that index I will only touch the memory owned
by array object S.

This is one area where Ada95 differs from Ada83, which made no such
guarantee.