Re: Ada safety road

[Franco Mazzanti <fmazz@tin.it>]

Keith Thompson wrote:
> 
> kilgallen@eisner.decus.org (Larry Kilgallen) writes:
> > In article <928703068.617.98@news.remarQ.com>, "Vladimir Olensky" <vladimir_olensky@yahoo.com> writes:
> > > But I see one problem here.  All this information is scattered
> > > around RM.
> >
> > In order to be definitive, the RM should not duplicate information in
> > various locations, and thus cannot be in the ideal exposition format
> > for all purposes.
> 
> The RM already has several "informative" annexes, which are not
> strictly part of the standard.  Annexes K (attributes) and L (pragmas)
> are particularly useful, even though (or rather *because*) they
> duplicate information scattered around the RM.  An informative annex
> listing all occurrences of erroneous execution and bounded errors
> would have been useful.
> 
> As I was writing this, I realized we already have the next best thing.
> The entry for "erroneous" in the RM's index refers to all the places
> in the RM where the term is used; likewise for "bounded error".
> 
> This brings up a pet peeve of mine: the word "erroneous" was a poor
> choice of terminology.  It's an existing English word with a
> well-defined meaning.  When I use the word in an Ada context, I very
> often have to explain the Ada-specific meaning.  It also fails to make
> it clear that it's the execution of a construct that's erroneous, not
> the construct itself.  Norman Cohen, in his book "Ada as a Second
> Language", uses the phrase "unbounded error", which is much clearer.
> Another good term is "undefined behavior", used by the C and C++
> standards for (essentially) the same concept.
> 
...

Some time ago I did that job of collecting from all the RM all this
kind of information related to erroneous executions. It took a long
time, 
and it has been a much harder job rather than what initially expected,
but in the end I think I succeded in getting the whole picture.
If anybody is interested, the report can downloaded by anonymous ftp
from:
  ftp://rep1.iei.pi.cnr.it/pub/mazzanti/publications/EEG.ps
(it is an IEI report)
Some printed copies are also available under request.

It is almost two years old, so some details concerning new or 
recently revised Ada Commentaries may be absent.

Any comments on that report are still welcome.

   Franco Mazzanti   
   Istituto di Elaborazione della Informazione
   Via S.Maria 46, 56126 Pisa, ITALY
   Tel: +39050-593447/593400, Fax: +39-50-554342
   e-mail: mazzanti@iei.pi.cnr.it
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