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
Path: 
 g2news1.google.com!news1.google.com!postnews.google.com!79g2000hsk.googlegroups.com!not-for-mail
From: Adam Beneschan <adam@irvine.com>
Newsgroups: comp.lang.ada
Subject: Re: On pragma Precondition and types
Date: Thu, 2 Oct 2008 08:02:16 -0700 (PDT)
Organization: http://groups.google.com
Message-ID: <3818fb9e-4599-400d-aa01-431a0b7101fa@79g2000hsk.googlegroups.com>
References: <48e4dc3b$0$6604$9b4e6d93@newsspool3.arcor-online.net>
NNTP-Posting-Host: 66.126.103.122
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
X-Trace: posting.google.com 1222959737 10651 127.0.0.1 (2 Oct 2008 15:02:17
 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Thu, 2 Oct 2008 15:02:17 +0000 (UTC)
Complaints-To: groups-abuse@google.com
Injection-Info: 79g2000hsk.googlegroups.com; posting-host=66.126.103.122;
	posting-account=duW0ogkAAABjRdnxgLGXDfna0Gc6XqmQ
User-Agent: G2/1.0
X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.7.12)
	Gecko/20050922 Fedora/1.7.12-1.3.1,gzip(gfe),gzip(gfe)
Xref: g2news1.google.com comp.lang.ada:2195
Date: 2008-10-02T08:02:16-07:00
List-Id: <comp.lang.ada>

On Oct 2, 7:35 am, Georg Bauhaus <rm.dash-bauh...@futureapps.de>
wrote:
> Suppose there is a type T with operations P and F,
>
>    type T is private;
>
>    procedure P (X: in out T);
>    function  F (X: T) return Boolean;
>
> I want to add a precondition of P. The precondition
> involves F,
>
>    procedure P (X: in out T);
>    pragma Precondition (F(X));
>
>    function  F (X: T) return Boolean;
>
> But when the compiler sees the pragma Precondition,
> it has not yet seen F.  Therefore, by the principle
> of linear reading, the precondition cannot be compiled,
> IIUC.
>
> Could there be a rule for pragmas, say, allowing forward
> references?

If you just heard a strange high-pitched noise, it was the sound of
several dozen compiler maintainers reacting to your proposal in
terror.  Sort of the same sound Janet Leigh made in "Psycho"........

                                 -- Adam