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: 103376,8893269a4640c798
X-Google-Attributes: gid103376,public
X-Google-ArrivalTime: 2003-07-17 15:42:37 PST
Path: 
 archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!fu-berlin.de!uni-berlin.de!82-43-33-75.cable.ubr01.croy.blueyonder.co.UK!not-for-mail
From: "Nick Roberts" <nickroberts@blueyonder.co.uk>
Newsgroups: comp.lang.ada
Subject: Re: terminate applications
Date: Thu, 17 Jul 2003 23:44:17 +0100
Message-ID: <bf78or$boi9c$1@ID-25716.news.uni-berlin.de>
References: <bf5uks$8n0$1@e3k.asi.ansaldo.it>
 <bf6upn$b2m7q$1@ID-25716.news.uni-berlin.de>
 <23ERa.75454$OZ2.12362@rwcrnsc54>
NNTP-Posting-Host: 82-43-33-75.cable.ubr01.croy.blueyonder.co.uk (82.43.33.75)
X-Trace: news.uni-berlin.de 1058481755 12339500 82.43.33.75 (16 [25716])
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 5.50.4807.1700
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700
Xref: archiver1.google.com comp.lang.ada:40445
Date: 2003-07-17T23:44:17+01:00
List-Id: <comp.lang.ada>

"Mark A. Biggar" <mark@biggar.org> wrote in message
news:23ERa.75454$OZ2.12362@rwcrnsc54...

> If you really need to abort an Ada program form some
> deeply nested code, raising an exception is a reasonable
> way to do it.  All clean up actions are guaranteed to
> happen and you can add a handler to the main procedure
> to do any last gasp stuff cleanly.

Absolutely right.

Furthermore, on reviewing the first example I gave, I see that it is
rubbish! You cannot 'goto' out of a procedure in Ada. Sorry.

Perhaps it could be corrected to the following:

   with Ada.Text_IO; use Ada.Text_IO;
   procedure exit_from_prog is
      Count: Natural := 0;
      My_Exception: exception;
      procedure Inner_Proc is
      begin
         Put_Line("Hello World");
         if Count = 20 then
            raise My_Exception;
         end if;
      end;
   begin
      loop
         Inner_Proc;
         Count := Count + 1;
      end loop;
   exception
      when My_Exception =>
         Put_Line("Clean termination!");
      when others =>
         Put_Line("Something unexpected!");
   end;

I have tested this on GNAT!

The second example, and the reason why it is better, remains correct.

--
Nick Roberts
Jabber: debater@charente.de [ICQ: 159718630]