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From: Toon Moene <toon@moene.indiv.nluug.nl>
Subject: Re: Fortran or Ada?
Date: 1998/10/03
Date: 1998-10-03T00:00:00+00:00	[thread overview]
Message-ID: <6v5t20$ecr$2@newnews.nl.uu.net> (raw)
In-Reply-To: 36164A60.FA563BB0@icon.fi

Niklas Holsti <nholsti@icon.fi> wrote:

> I wrote:

> > No.  The problem is in the expectation of Ada programmers that software
> > errors should be handled the same as hardware errors, by trapping them 
via a
> > software trap handler specified by the programmer.  Software errors 
should be
> > handled by careful, defensive programming, not CYA.

and you quoted from the report:

<quote>

> [ ... ] The exception was detected, but inappropriately handled because
> the view had been taken that software should be considered correct
> until it is shown to be at fault. The Board has reason to believe
> that this view is also accepted in other areas of Ariane 5 software
> design. The Board is in favour of the opposite view, that software
> should be assumed to be faulty until applying the currently accepted
> best practice methods can demonstrate that it is correct."

</quote>

> I think the report criticises the assumption that a trap ("exception")
> indicated hardware failure rather than software failure. I don't
> see any criticism of software exception-handling as such, just a
> suggestion that the most likely cause of a software exception is
> a software fault, with which I agree.

OK, good point - I was probably reading it in a different way because I am 
not used to thinking of "exceptions" as anything a "user routine" should take 
care of.

In my mind, an exception is a sign that the assumptions behind the 
(physics/mathematics) of your model is wrong, and - even though that pertains 
to a large extent also to rocket ascent - this would not lead to a reasonably 
safe procedure here.

-- 
Toon Moene (mailto:toon@moene.indiv.nluug.nl)
Saturnushof 14, 3738 XG  Maartensdijk, The Netherlands
Phone: +31 346 214290; Fax: +31 346 214286
g77 Support: mailto:fortran@gnu.org; egcs: mailto:egcs-bugs@cygnus.com




  reply	other threads:[~1998-10-03  0:00 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <36068E73.F0398C54@meca.polymtl.ca>
1998-09-22  0:00 ` Fortran or Ada? Gisle S{lensminde
1998-09-22  0:00   ` Jeff Templon
1998-09-22  0:00     ` dewarr
1998-09-23  0:00       ` Jeff Templon
1998-09-23  0:00         ` Corey Minyard
1998-09-24  0:00           ` Craig Burley
1998-09-25  0:00             ` dewarr
1998-09-25  0:00               ` Jonathan Guthrie
1998-09-26  0:00               ` Craig Burley
1998-09-26  0:00                 ` dewarr
1998-09-26  0:00                   ` Robert B. Love 
1998-09-26  0:00                   ` Craig Burley
1998-09-24  0:00           ` Joel Seidman
1998-09-24  0:00         ` Marc A. Criley
1998-09-24  0:00           ` dewarr
1998-09-24  0:00             ` Robert I. Eachus
1998-09-24  0:00               ` William Clodius
1998-09-25  0:00                 ` dewarr
1998-09-25  0:00               ` dewarr
1998-09-25  0:00                 ` Robert I. Eachus
1998-09-25  0:00                   ` dewarr
1998-09-25  0:00             ` jbs
1998-09-26  0:00               ` dewarr
1998-09-28  0:00                 ` jbs
1998-09-29  0:00                   ` William B. Clodius
1998-09-30  0:00                     ` jbs
1998-09-30  0:00                       ` dewarr
1998-09-30  0:00                         ` jbs
1998-09-30  0:00                           ` William Clodius
1998-09-30  0:00                       ` William Clodius
1998-10-03  0:00                       ` Niklas Holsti
1998-10-03  0:00                         ` Toon Moene
1998-10-03  0:00                           ` Niklas Holsti
1998-10-03  0:00                             ` Toon Moene [this message]
1998-10-04  0:00                               ` Niklas Holsti
1998-10-05  0:00                                 ` Michel OLAGNON
1998-10-05  0:00                                   ` Ian St. John
1998-10-05  0:00                                     ` dewarr
1998-10-05  0:00                                       ` Ian St. John
1998-10-06  0:00                                         ` dewarr
1998-10-06  0:00                                           ` Ian St. John
1998-10-08  0:00                                             ` Offtopic Airport Diversion (Was: Fortran or Ada?) Harold Stevens ** PLEASE SEE SIG **
1998-10-08  0:00                                               ` Ian St. John
1998-10-08  0:00                                             ` Fortran or Ada? Gary L. Scott
1998-10-06  0:00                                           ` Toon Moene
1998-10-06  0:00                                             ` Jonathan Guthrie
1998-10-06  0:00                                           ` James Giles
1998-10-06  0:00                                             ` Mark A Biggar
1998-10-06  0:00                                               ` James Giles
1998-10-07  0:00                                                 ` dewarr
1998-10-07  0:00                                             ` dewarr
1998-10-05  0:00                                     ` Richard D Riehle
1998-10-05  0:00                                       ` dewarr
1998-10-06  0:00                                     ` Michel OLAGNON
1998-10-07  0:00                                       ` Ian St. John
1998-09-29  0:00                   ` Dean F. Sutherland
1998-09-29  0:00                   ` Dean F. Sutherland
1998-09-29  0:00                   ` Gautier.DeMontmollin
1998-09-29  0:00                   ` Dean F. Sutherland
1998-10-02  0:00                   ` Geoff Bull
1998-10-02  0:00                   ` Robert I. Eachus
1998-10-02  0:00                     ` jbs
1998-10-02  0:00                       ` William Clodius
1998-10-03  0:00                         ` jbs
1998-10-03  0:00                           ` Larry Elmore
1998-10-06  0:00                           ` Robert I. Eachus
1998-10-06  0:00                             ` Pat Rogers
1998-09-24  0:00           ` Jeff Templon
1998-09-25  0:00             ` Dale Stanbrough
1998-09-30  0:00               ` Daniel Barker
1998-09-30  0:00                 ` Lawrence Kirby
1998-10-01  0:00                   ` Aaron Crane
1998-10-02  0:00                 ` Fortran or Ada or gobbledygook? Wes Groleau
1998-10-05  0:00                 ` Fortran or Ada? Terry Devine
1998-09-25  0:00             ` dewarr
     [not found]           ` <6udre0$ha1$1@nnrp1.dejane <6utg60$h6l$1@nnrp1.dejanews.com>
1998-10-01  0:00             ` robin_v
1998-09-22  0:00     ` Corey Minyard
1998-09-22  0:00     ` Larry Kilgallen
1998-09-22  0:00     ` Rakesh Malhotra
1998-09-23  0:00     ` Frank Ecke
1998-09-23  0:00   ` bglbv
1998-09-23  0:00     ` Robert I. Eachus
1998-09-24  0:00       ` Richard D Riehle
1998-09-23  0:00 Marin David Condic, 561.796.8997, M/S 731-96
  -- strict thread matches above, loose matches on Subject: below --
1998-09-23  0:00 Marin David Condic, 561.796.8997, M/S 731-96
1998-09-23  0:00 ` Gisle S{lensminde
1998-09-24  0:00   ` John McCabe
1998-09-24  0:00     ` Dean F. Sutherland
1998-09-24  0:00     ` Gisle S{lensminde
1998-09-24  0:00 ` Samuel T. Harris
1998-09-24  0:00 Walt Brainerd
1998-09-25  0:00 ` Robert I. Eachus
1998-09-25  0:00 ` dewarr
1998-10-05  0:00 robin
1998-10-05  0:00 Condic, Marin D.
1998-10-05  0:00 Robert I. Eachus
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