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From: "Veli-Pekka Nousiainen" <vp.nousiainen@remove_this_eiffel.fi>
Subject: Re: Building blocks (Was: Design By Contract)
Date: 1997/09/23
Date: 1997-09-23T00:00:00+00:00	[thread overview]
Message-ID: <01bcc7f6$638b7f60$108142c1@Yeif-1.eiffel.fi> (raw)
In-Reply-To: mheaney-ya023680002209971930310001@news.ni.net




Matthew Heaney <mheaney@ni.net> wrote in article
<mheaney-ya023680002209971930310001@news.ni.net>...
> In article <3423BE13.9C3852A4@munich.netsurf.de>, Joachim Durchholz
> <joachim.durchholz@munich.netsurf.de> wrote:
> 
<SNIP> 
> 
> >What's disciplined about Eiffel exceptions is not the retry instruction,
> >which is somewhat secondary. The discipline of exception handling in
> >Eiffel has other sources:
> >- A precise definition of what an exception indicates (namely a routine
> >that fails to fulfill its postcondition - other languages, lacking the
> >notion of postcondition, can't even start to compete)
> 
> This statement confuses syntax with semantics.  By a very deliberate
choice
> during language design, 
> there is not always a way in Ada to state syntactically what the
> postcondition of a subprogram is (and never any way to state what
> exceptions are propagated by a subprogram).   However, in Ada, you do
state
> what the postcondition is, in the form of a comment.  It is clearly not
the
> case that Ada - or any other language - "lacks a notion of
postcondition." 

It is clear to me that postconditioning is missing in all other languages
exept Eiffel (Sather???). If all you need is comments, then my old
hex-assembler for an 8-bit processor is all O-O with DbC, I just comment
:-)
> 
> So yes, in Ada, you really do raise an exception when you are unable to
> satisfy a postcondition, it's just that the postcondition and possible
> exceptions raised cannot be stated as part of Ada syntax; they must be
> stated as a comment.
> 
<SNIP> 
> 
IMO
-- 
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Veli-Pekka Nousiainen
Sokinsuontie 3 A 1, FIN-02760 Espoo, Finland
TEL +358-9-859 2025 ; GSM 0400-5940 824
e-mail: vp.nousiainen@remove_this_eiffel.fi
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  reply	other threads:[~1997-09-23  0:00 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-09-09  0:00 Building blocks (Was: Design By Contract) Marc Wachowitz
1997-09-15  0:00 ` Joachim Durchholz
1997-09-17  0:00 ` Paul Johnson
1997-09-18  0:00   ` Jon S Anthony
1997-09-18  0:00   ` Stephen Leake
1997-09-18  0:00     ` W. Wesley Groleau x4923
1997-09-21  0:00       ` Matthew Heaney
1997-09-18  0:00     ` Mark L. Fussell
1997-09-19  0:00       ` Jon S Anthony
1997-09-23  0:00         ` Mark L. Fussell
     [not found]       ` <11861963wnr@eiffel.demon.co.uk>
1997-09-19  0:00         ` Mark L. Fussell
1997-09-19  0:00       ` Robert A Duff
1997-09-20  0:00         ` Joachim Durchholz
1997-09-22  0:00           ` Matthew Heaney
1997-09-23  0:00             ` Veli-Pekka Nousiainen [this message]
1997-10-03  0:00               ` Robert I. Eachus
1997-10-04  0:00                 ` Paul Johnson
1997-10-14  0:00                   ` Robert I. Eachus
1997-09-23  0:00             ` Joachim Durchholz
1997-09-23  0:00           ` Jon S Anthony
1997-09-24  0:00           ` Alan E & Carmel J Brain
1997-09-25  0:00             ` Anonymous
1997-09-30  0:00               ` Alan E & Carmel J Brain
1997-09-30  0:00                 ` Matthew Heaney
1997-09-30  0:00                   ` W. Wesley Groleau x4923
1997-09-30  0:00                     ` Matthew Heaney
1997-10-01  0:00                     ` Alan E & Carmel J Brain
1997-09-30  0:00                   ` Neil Wilson
1997-09-30  0:00                     ` Stephen Leake
1997-10-01  0:00                 ` Anonymous
1997-10-01  0:00                   ` Paul M Gover
1997-10-04  0:00                     ` Paul Johnson
1997-10-04  0:00                       ` Matthew Heaney
1997-10-15  0:00                         ` Paul Johnson
1997-10-15  0:00                           ` Matthew Heaney
1997-10-16  0:00                             ` Joachim Durchholz
1997-10-17  0:00                               ` Robert I. Eachus
1997-10-16  0:00                           ` Joachim Durchholz
1997-10-22  0:00                           ` Reimer Behrends
1997-10-01  0:00                   ` Joachim Durchholz
1997-10-02  0:00                   ` Robert A Duff
1997-10-02  0:00                     ` Tucker Taft
1997-10-02  0:00                       ` Matthew Heaney
1997-10-03  0:00                     ` Stephen Leake
1997-10-04  0:00                     ` Matthew Heaney
1997-10-07  0:00                       ` Robert A Duff
1997-09-24  0:00           ` Richard A. O'Keefe
1997-09-18  0:00   ` Robert Dewar
  -- strict thread matches above, loose matches on Subject: below --
1997-09-11  0:00 Robert Dewar
1997-09-09  0:00 Marc Wachowitz
1997-09-02  0:00 Design By Contract Jon S Anthony
     [not found] ` <JSA.97Sep3201329@alexandria.organon.com>
1997-09-04  0:00   ` Paul Johnson
     [not found]     ` <5un58u$9ih$1@gonzo.sun3.iaf.nl>
1997-09-06  0:00       ` Building blocks (Was: Design By Contract) Joachim Durchholz
1997-09-08  0:00       ` Paul Johnson
1997-09-08  0:00         ` Brian Rogoff
1997-09-09  0:00           ` W. Wesley Groleau x4923
1997-09-09  0:00           ` Matthew Heaney
1997-09-09  0:00             ` Brian Rogoff
1997-09-09  0:00             ` W. Wesley Groleau x4923
1997-09-10  0:00               ` Robert A Duff
1997-09-12  0:00                 ` Jon S Anthony
1997-09-10  0:00             ` Robert Dewar
1997-09-12  0:00               ` Paul Johnson
1997-09-14  0:00                 ` Robert Dewar
1997-09-14  0:00                 ` Robert Dewar
1997-09-15  0:00                   ` John G. Volan
1997-09-14  0:00                 ` Robert Dewar
1997-09-12  0:00               ` Jon S Anthony
1997-09-12  0:00                 ` Robert Dewar
1997-09-16  0:00                   ` Brian Rogoff
1997-09-10  0:00             ` Paul Johnson
1997-09-10  0:00               ` Darren New
1997-09-10  0:00               ` Matthew Heaney
1997-09-09  0:00           ` Veli-Pekka Nousiainen
1997-09-09  0:00           ` Veli-Pekka Nousiainen
1997-09-09  0:00             ` Jon S Anthony
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