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: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!mx05.eternal-september.org!feeder.eternal-september.org!nuzba.szn.dk!news.jacob-sparre.dk!loke.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail
From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Elaboration order handling (Was: Bug in 'gnatmake')
Date: Wed, 19 Jun 2013 17:26:20 -0500
Organization: Jacob Sparre Andersen Research & Innovation
Message-ID: <kptb6c$gh$1@loke.gir.dk>
References: 
 <7f33982d-3bcf-452e-a3b3-3a0a28505ff1@x20g2000vbe.googlegroups.com>
 <87r4g0g9c0.fsf@adaheads.sparre-andersen.dk> <lysj0glghs.fsf@pushface.org>
 <87ip1bg4z2.fsf_-_@adaheads.sparre-andersen.dk>
 <wcczjun4a7y.fsf@shell01.TheWorld.com>
 <db04ccb2-a3f7-4daa-8846-df9a992a0f85@googlegroups.com>
 <wccip1acmt5.fsf@shell01.TheWorld.com>
NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net
X-Trace: loke.gir.dk 1371680780 529 69.95.181.76 (19 Jun 2013 22:26:20 GMT)
X-Complaints-To: news@jacob-sparre.dk
NNTP-Posting-Date: Wed, 19 Jun 2013 22:26:20 +0000 (UTC)
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.5931
X-RFC2646: Format=Flowed; Original
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157
Xref: news.eternal-september.org comp.lang.ada:15850
Date: 2013-06-19T17:26:20-05:00
List-Id: <comp.lang.ada>

"Robert A Duff" <bobduff@shell01.TheWorld.com> wrote in message 
news:wccip1acmt5.fsf@shell01.TheWorld.com...
...
> I don't see what the big deal is.  Any legal Ada identifier can be
> represented as a Wide_Wide_String, and every Ada 2012 implementation
> supports the "<" operator on those.  So one trivial solution is to
> simply sort based on that "<", in cases where the current rules about
> 'with' clauses and pragmas leave the order undefined.

That doesn't work because Ada identifiers are case-insensitive, while "<" is 
case-sensitive. You could get orders that depend on the case of the 
identifiers, and in fact you could get children coming before parents.

A direct conversion to some specific case doesn't work portably in Unicode 
(because it depends on what version Unicode you are using, while the 
case-insensitive compare is guarenteed to work the same in all versions of 
Unicode).

The net effect is that ordering is not very reliable in case-insensitive 
Unicode identifiers, like Ada's. Cool, huh?

                                                Randy.