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From: milkweed@plainfield.bypass.com (Anders Pytte)
Subject: Re: Papers on the Ariane-5 crash and Design by Contract
Date: 1997/03/18
Date: 1997-03-18T00:00:00+00:00	[thread overview]
Message-ID: <milkweed-1803971317060001@port4.chester.smallmedia.com> (raw)
In-Reply-To: 5gm8a6$2qu$2@news.irisa.fr

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In article <5gm8a6$2qu$2@news.irisa.fr>, jezequel@irisa.fr (Jean-Marc
Jezequel) wrote:

> >I expect Meyers to push his own products, but to imply the Ariane-5 crash
> >was caused by poor choice of programming language seems out of step with
> >his otherwise impeccable manners.
> 
> Unless our English is so bad that it betrays our thinking, we 
> *never* implied such a thing. Just a point in a case: Eiffel simply did
not exist when they 
> worked on Ariane4. Let me quote the relevant section of the paper:
> 
> <<Is it the programming language's fault?
> Although one may criticize the Ada exception mechanism, it could have
been used here
>  to catch the exception. In fact, quoting the report: [omitted]
> In other words the potential problem of failed arithmetic conversions
was recognized.
>  Unfortunately, the fatal exception was among the three that were not
monitored,
>  not the four that were.>>
> 
> In case it is not clear enough, I repeat again: *it is not a language problem*
> Let me quote another part of the paper:
> <<Does this mean that the crash would automatically have been avoided
had the mission used
> a language and method supporting built-in assertions and Design by
Contract? >>
> 
> Please note the "language and method supporting built-in assertions and
Design by Contract"
> and please do not reduce it to : "a language". 

Let me quote the entire paragraph:

"Does this mean that the crash would automatically have been avoided had
the mission used a language and method supporting built-in assertions and
Design by Contract? Although it is always risky to draw such
after-the-fact conclusions, the answer is probably yes�"

And further:

"To attempt to reuse software without Eiffel-like assertions is to invite
failures of potentially disastrous consequences."

This is somewhat confusing, since assertions and design by contract can be
easily effected in Ada, the language used for Ariane5 (and in the other
languages disparaged in the article). I acknowledge that a strict reading
of the article would not prove my point, but the implication is obvious to
an unbiased reader, that the writer believes the use of Eiffel, as opposed
to "CORBA to C++ to Visual Basic to ActiveX to Java" and ofcourse Ada,
"probably" would have prevented the crash.

Don't get me wrong: I think Eiffel is a fine language.

My point was that assertions and design by contract are good, but are not
enforced by Eiffel any more than any other modern programming language.
The presence of "built-in" assertions does not mean they will be used; a
person who would use assertions fastidiously in Eiffel is probably already
using them in C++ or Ada. If your article does not seem slanted to you,
that is probably because you wrote it - I am not the only reader that
detected a pro-Eiffel bias.

Anders.

-- 
Anders Pytte            Milkweed Software
RR 1, Box 227           Voice: (802) 472-5142
Cabot VT 05647          Internet: milkweed@plainfield.bypass.com




  reply	other threads:[~1997-03-18  0:00 UTC|newest]

Thread overview: 254+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-03-15  0:00 Papers on the Ariane-5 crash and Design by Contract Bertrand Meyer
1997-03-18  0:00 ` Ariane-5: can you clarify? (Re: Please do not start a language war) Jon S Anthony
1997-03-19  0:00 ` Papers on the Ariane-5 crash and Design by Contract Chris Brand
     [not found] ` <tz8ohcjv7cc.fsf@aimnet.com>
1997-03-16  0:00   ` Robert Dewar
1997-03-17  0:00     ` Please do not start a language war (was " Jean-Marc Jezequel
1997-03-18  0:00       ` Richard Irvine
     [not found]       ` <tz8913l930b.fsf_-_@aimnet.com>
1997-03-18  0:00         ` Ariane-5: can you clarify? (Re: Please do not start a language war) Gavin Collings
1997-03-18  0:00         ` Ariane-5: can you clarify? (Re: Please do not start a language war Roedy Green
1997-03-18  0:00       ` Please do not start a language war (was Re: Papers on the Ariane-5 crash and Design by Contract Ken Garlington
1997-03-19  0:00         ` Jean-Marc Jezequel
1997-03-19  0:00           ` Richard Kaiser
1997-03-21  0:00           ` Ken Garlington
1997-03-21  0:00             ` Jean-Marc Jezequel
1997-03-25  0:00               ` Ken Garlington
1997-03-26  0:00                 ` Trust but verify " Robert S. White
1997-03-25  0:00                   ` Bertrand Meyer
1997-03-26  0:00                     ` Robb Nebbe
1997-03-27  0:00                     ` Ken Garlington
1997-03-28  0:00                       ` Karel Th�nissen
1997-03-28  0:00                         ` Ken Garlington
1997-04-07  0:00                           ` Jean-Marc Jezequel
1997-03-28  0:00                       ` Jeffrey W. Stulin
1997-03-31  0:00                         ` Ken Garlington
1997-03-29  0:00                     ` the one and only real true kibo
     [not found]         ` <199703190839.JAA02652@stormbringer.irisa.fr>
1997-03-19  0:00           ` Please do not start a language war " Ken Garlington
1997-03-20  0:00             ` Robert S. White
1997-03-20  0:00               ` Martin Tom Brown
1997-03-21  0:00                 ` Wolfgang Gellerich
1997-03-21  0:00                 ` Robert S. White
1997-03-20  0:00               ` John L. Ahrens
1997-03-20  0:00             ` Roger T.
1997-03-21  0:00               ` Ken Garlington
1997-03-21  0:00               ` Jean-Marc Jezequel
1997-03-24  0:00                 ` Ken Garlington
1997-03-17  0:00   ` Bertrand Meyer
1997-03-18  0:00     ` John McCabe
1997-03-18  0:00       ` Ray McVay
1997-03-27  0:00         ` Robert Dewar
1997-03-29  0:00           ` the one and only real true kibo
1997-03-30  0:00             ` Nick Roberts
1997-04-06  0:00             ` Doctorb
1997-04-08  0:00         ` Ron Crocker
1997-04-11  0:00           ` Richard Riehle
1997-03-17  0:00   ` Nick Leaton
1997-03-17  0:00     ` Richard Kaiser
1997-03-18  0:00     ` Richard Kaiser
1997-03-18  0:00       ` Nick Leaton
1997-03-18  0:00         ` "Paul E. Bennett"
1997-03-19  0:00           ` Nick Leaton
1997-03-24  0:00           ` Joachim Durchholz
1997-03-25  0:00             ` Robert Dewar
1997-03-31  0:00               ` Jan Galkowski
1997-03-31  0:00               ` Joachim Durchholz
1997-04-02  0:00                 ` Robert Dewar
1997-04-03  0:00                   ` Martin Tom Brown
1997-04-04  0:00                   ` Derek Clarke
1997-04-04  0:00                   ` Jonathan Egre'
1997-04-06  0:00                     ` Robert Dewar
1997-04-06  0:00                       ` Nick Roberts
1997-03-31  0:00             ` Alexander Anderson
1997-04-01  0:00             ` Alexander Anderson
1997-04-02  0:00             ` Ken Garlington
1997-03-20  0:00         ` John the Hamster
1997-03-18  0:00     ` Richard Kaiser
1997-03-18  0:00       ` Jean-Marc Jezequel
1997-03-19  0:00         ` Ken Garlington
1997-03-18  0:00       ` Nick Leaton
1997-03-19  0:00         ` Richard Kaiser
1997-03-19  0:00           ` Jean-Marc Jezequel
1997-03-19  0:00             ` Richard Kaiser
1997-03-19  0:00           ` Fergus Henderson
     [not found]     ` <tz8g1xtzx9y.fsf@aimnet.com>
1997-03-18  0:00       ` Anders Pytte
1997-03-18  0:00         ` Jean-Marc Jezequel
1997-03-18  0:00           ` Anders Pytte [this message]
1997-03-19  0:00             ` Programming language fanaticism! Louis Bastarache
1997-03-20  0:00               ` Anders Pytte
1997-03-20  0:00             ` Papers on the Ariane-5 crash and Design by Contract Matt Kennel (Remove 'nospam' to reply)
1997-03-24  0:00             ` Joachim Durchholz
1997-03-24  0:00               ` Anders Pytte
1997-03-26  0:00                 ` Matt Kennel (Remove 'nospam' to reply)
1997-03-29  0:00                   ` Anders Pytte
1997-03-29  0:00                     ` Steve Furlong
1997-03-26  0:00                 ` Robert Dewar
1997-03-27  0:00                   ` the one and only real true kibo
1997-03-29  0:00                   ` the one and only real true kibo
1997-03-29  0:00                     ` Nick S Bensema
1997-03-30  0:00                       ` the one and only real true kibo
1997-03-18  0:00           ` Anders Pytte
1997-03-21  0:00           ` Ken Garlington
1997-03-21  0:00             ` Bertrand Meyer
1997-03-21  0:00               ` William Clodius
1997-03-21  0:00                 ` Bertrand Meyer
1997-03-23  0:00                   ` William Clodius
1997-03-23  0:00                   ` the one and only real true kibo
1997-03-22  0:00               ` Fergus Henderson
1997-03-22  0:00                 ` Bertrand Meyer
1997-03-23  0:00                   ` the one and only real true kibo
1997-03-23  0:00                     ` Anders Pytte
1997-03-24  0:00                   ` FUD (Re: Papers on the Ariane-5 crash and Design by Contract) Alexander Anderson
1997-03-24  0:00                   ` Alexander Anderson
1997-03-23  0:00               ` Papers on the Ariane-5 crash and Design by Contract Anders Pytte
     [not found]                 ` <3335BC24.13728473@eiffel.com>
1997-03-23  0:00                   ` Bertrand Meyer
1997-03-24  0:00                     ` Robert Dewar
1997-03-31  0:00                       ` Ken Garlington
1997-04-01  0:00                         ` Bertrand Meyer
1997-03-25  0:00                     ` Ken Garlington
1997-03-24  0:00                 ` Ken Garlington
1997-03-24  0:00                 ` the one and only real true kibo
1997-03-24  0:00               ` John Hogg
1997-03-24  0:00               ` Ken Garlington
1997-03-26  0:00                 ` Robert Dewar
1997-03-26  0:00                   ` Ken Garlington
     [not found]                     ` <E7ox17.MKx@syd.csa.com.au>
1997-03-28  0:00                       ` Ken Garlington
1997-03-18  0:00         ` Laurent Moussault
1997-03-17  0:00   ` Alexander Anderson
1997-03-17  0:00   ` Please do not start a language war (was " Jon S Anthony
1997-03-18  0:00     ` Kent Tong
1997-03-20  0:00       ` Ranan Fraer
1997-03-17  0:00   ` Robert I. Eachus
1997-03-17  0:00     ` Martin Tom Brown
1997-03-17  0:00   ` John McCabe
     [not found]     ` <tz8n2s1hrdc.fsf@aimnet.com>
1997-03-20  0:00       ` John McCabe
1997-03-20  0:00       ` John McCabe
1997-03-20  0:00         ` Jean-Marc Jezequel
1997-03-20  0:00           ` John McCabe
1997-03-21  0:00             ` Niall Cooling
1997-03-21  0:00               ` Gavin Collings
1997-03-27  0:00                 ` Joachim Durchholz
1997-04-03  0:00                   ` Robert I. Eachus
1997-04-04  0:00                     ` Derek Clarke
1997-04-04  0:00                     ` Chris Beer
1997-04-03  0:00                   ` Gavin Collings
1997-04-03  0:00                     ` Ken Garlington
1997-04-04  0:00                       ` Derek Clarke
1997-04-04  0:00                     ` Derek Clarke
1997-04-06  0:00                       ` Robert Dewar
1997-04-07  0:00                         ` Ken Garlington
1997-04-09  0:00                           ` Gavin Collings
1997-04-04  0:00                   ` Ken Garlington
1997-04-04  0:00                     ` Robert Dewar
1997-04-03  0:00                 ` Robin Rosenberg
1997-03-24  0:00             ` Ken Garlington
1997-03-26  0:00           ` Thomas Beale
1997-03-26  0:00             ` Ken Garlington
1997-03-21  0:00       ` "Paul E. Bennett"
1997-03-22  0:00     ` Nigel Tzeng
1997-03-23  0:00       ` John McCabe
1997-03-17  0:00   ` Paul Johnson
1997-03-17  0:00     ` Enrico Facchin - Sartori E.T.
1997-03-19  0:00       ` Anders Pytte
1997-03-18  0:00     ` Ken Garlington
1997-03-18  0:00   ` Tarjei Jensen
1997-03-18  0:00   ` Ken Garlington
1997-03-19  0:00     ` Eric M. Boyd
1997-03-19  0:00       ` Jeffrey W. Stulin
     [not found]       ` <3345cd60.2092398@news.sydney.apana.org.au>
1997-04-03  0:00         ` Ariane-5 crash , Eiffel and Ada Nick Leaton
1997-04-03  0:00         ` Jeffrey W. Stulin
1997-04-08  0:00         ` AdaWorks
1997-03-18  0:00   ` Papers on the Ariane-5 crash and Design by Contract Jon S Anthony
1997-03-18  0:00   ` Jon S Anthony
1997-03-19  0:00     ` Ron Forrester
1997-03-21  0:00       ` Ken Garlington
1997-03-22  0:00         ` Ron Forrester
1997-03-18  0:00   ` Jon S Anthony
1997-03-18  0:00   ` Robert I. Eachus
1997-03-18  0:00   ` Jon S Anthony
1997-03-18  0:00   ` Ulrich Windl
1997-03-19  0:00   ` Karel Th�nissen
1997-03-19  0:00   ` Jon S Anthony
1997-03-19  0:00   ` Ken Garlington
1997-03-20  0:00     ` Martin Tom Brown
1997-03-21  0:00       ` Frank Manning
1997-03-21  0:00         ` Martin Tom Brown
1997-03-23  0:00           ` Frank Manning
1997-03-25  0:00             ` Ken Garlington
1997-03-20  0:00     ` Richard Kaiser
1997-03-24  0:00       ` Ken Garlington
1997-03-19  0:00   ` Ken Garlington
1997-03-19  0:00   ` Karel Th�nissen
1997-03-19  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) Karel Th�nissen
1997-03-19  0:00   ` Papers on the Ariane-5 crash and Design by Contract Jon S Anthony
1997-03-20  0:00     ` Jean-Marc Jezequel
1997-03-24  0:00       ` Ken Garlington
1997-03-20  0:00     ` Paul Johnson
1997-03-24  0:00       ` Ken Garlington
1997-03-24  0:00         ` Design by Contract in C++ (was Re: Papers on the Ariane-5 crash and Design by Contract) Anders Pytte
1997-03-19  0:00   ` Papers on the Ariane-5 crash and Design by Contract Nick Leaton
1997-03-20  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) Karel Th�nissen
1997-03-20  0:00   ` Nick Leaton
1997-03-20  0:00   ` Papers on the Ariane-5 crash and Design by Contract Robert I. Eachus
1997-03-20  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) Nick Leaton
1997-03-20  0:00   ` Papers on the Ariane-5 crash and Design by Contract Robert I. Eachus
1997-03-21  0:00   ` Please do not start a language war (was " Jon S Anthony
1997-03-21  0:00   ` Ulrich Windl
     [not found]   ` <tz8sp1qiywm.fsf@aimnet.com>
1997-03-21  0:00     ` ae59
1997-03-21  0:00   ` Alexander Anderson
1997-03-23  0:00     ` "Paul E. Bennett"
1997-03-22  0:00   ` Jon S Anthony
1997-03-28  0:00     ` Matt Kennel (Remove 'nospam' to reply)
1997-03-22  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) Stuart Yeates
1997-03-22  0:00   ` Papers on the Ariane-5 crash and Design by Contract Bertrand Meyer
1997-03-22  0:00     ` Anders Pytte
1997-03-23  0:00       ` Steve Furlong
1997-03-24  0:00         ` Anders Pytte
1997-03-24  0:00           ` Simulating Eiffel-style assertions (was: Papers on the Ariane-5 crash and Design by Contract) Wolfgang Reddig
1997-03-24  0:00             ` Anders Pytte
1997-03-25  0:00               ` Wolfgang Reddig
1997-03-25  0:00                 ` Anders Pytte
1997-03-31  0:00                 ` Joachim Durchholz
1997-03-26  0:00             ` Alan Brain
1997-03-26  0:00               ` Wolfgang Reddig
1997-03-29  0:00                 ` How old time languages survive EJon
1997-03-22  0:00   ` Papers on the Ariane-5 crash and Design by Contract Bertrand Meyer
1997-03-23  0:00     ` Dale Stanbrough
     [not found]       ` <3335E18E.33590565@eiffel.com>
1997-03-23  0:00         ` FUD (Re: Papers on the Ariane-5 crash and Design by Contract) Bertrand Meyer
1997-03-24  0:00           ` William Grosso
1997-03-24  0:00             ` Brad Appleton
1997-03-24  0:00             ` Bertrand Meyer
1997-03-24  0:00             ` William Clodius
1997-03-24  0:00     ` Papers on the Ariane-5 crash and Design by Contract Robert Dewar
1997-03-24  0:00       ` Manners (was Re: Papers on the Ariane-5 crash and Design by Contract) Bertrand Meyer
1997-03-25  0:00         ` the one and only real true kibo
1997-03-24  0:00   ` Papers on the Ariane-5 crash and Design by Contract Ken Garlington
1997-03-27  0:00     ` Joachim Durchholz
1997-03-31  0:00       ` Ken Garlington
1997-04-06  0:00         ` Joachim Durchholz
1997-03-24  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) Nick Leaton
1997-03-24  0:00   ` Papers on the Ariane-5 crash and Design by Contract Robb Nebbe
1997-03-24  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) William Clodius
1997-03-24  0:00   ` Ken Garlington
1997-03-24  0:00   ` Papers on the Ariane-5 crash and Design by Contract Ken Garlington
1997-03-24  0:00   ` Alexander Anderson
1997-03-24  0:00   ` Jon S Anthony
1997-03-24  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) Ken Garlington
1997-03-24  0:00   ` Papers on the Ariane-5 crash and Design by Contract Ken Garlington
1997-03-25  0:00   ` Ariane-5: can you clarify? (Re: Please do not start a language war) David Starr
1997-03-25  0:00   ` Ken Garlington
1997-03-25  0:00   ` Ken Garlington
1997-03-25  0:00   ` Papers on the Ariane-5 crash and Design by Contract Robert I. Eachus
1997-03-26  0:00   ` Alexander Anderson
1997-03-26  0:00   ` Jon S Anthony
1997-03-26  0:00   ` Ken Garlington
1997-03-27  0:00   ` Trust but verify (was " Robert I. Eachus
1997-03-28  0:00   ` Jon S Anthony
1997-03-28  0:00   ` Trust but verify (was " Robert I. Eachus
1997-03-31  0:00   ` Ken Garlington
1997-03-23  0:00 ` the one and only real true kibo
  -- strict thread matches above, loose matches on Subject: below --
1997-03-17  0:00 Marin David Condic, 561.796.8997, M/S 731-93
1997-03-20  0:00 Marin David Condic, 561.796.8997, M/S 731-93
1997-03-25  0:00 ` Nick Roberts
1997-03-24  0:00 Marin David Condic, 561.796.8997, M/S 731-93
1997-03-27  0:00 Marin David Condic, 561.796.8997, M/S 731-93
1997-04-03  0:00 Adrian B.Y. Hoe
1997-04-05  0:00 ` Nick Roberts
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