From: Paul Johnson <Paul@treetop.demon.co.uk>
Subject: Re: Building blocks (Was: Design By Contract)
Date: 1997/10/04
Date: 1997-10-04T00:00:00+00:00 [thread overview]
Message-ID: <J87JkUA6zdN0Iwrm@treetop.demon.co.uk> (raw)
In-Reply-To: EACHUS.97Oct3164342@spectre.mitre.org
In article <EACHUS.97Oct3164342@spectre.mitre.org>, "Robert I. Eachus"
<eachus@spectre.mitre.org> writes
> Actually Ada does have a quite well defined concept of pre- and
>post- conditions for subprograms. However, they are implicit rather
>than defined as part of the syntax. This guarentees that the
>conditions are always true, but it makes it hard to add complex
>postconditions.
Yes, sort of.
[Positive subrange example deleted]
The problem is that it doesn't let you say things like
item: T is
require
not empty
> Which is better? I prefer the Ada approach, where you can, with a
>little bit of caution, always count on the value of the object meeting
>all of the rules for such objects,
You can count on it for Eiffel as well: invariants state this kind of
thing.
Paul.
--------------------------------+---------------------------------
Paul Johnson | You are lost in a maze of twisty
Email: Paul@treetop.demon.co.uk | little standards, all different.
paul.johnson@gecm.com |
next prev parent reply other threads:[~1997-10-04 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 ` 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
1997-10-03 0:00 ` Robert I. Eachus
1997-10-04 0:00 ` Paul Johnson [this message]
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 ` Richard A. O'Keefe
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 ` Joachim Durchholz
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
1997-10-02 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
1997-09-18 0:00 ` Jon S Anthony
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 ` Veli-Pekka Nousiainen
1997-09-09 0:00 ` Veli-Pekka Nousiainen
1997-09-09 0:00 ` Jon S Anthony
1997-09-09 0:00 ` W. Wesley Groleau x4923
1997-09-09 0:00 ` Matthew Heaney
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
1997-09-09 0:00 ` Brian Rogoff
1997-09-10 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
1997-09-12 0:00 ` Paul Johnson
1997-09-14 0:00 ` Robert Dewar
1997-09-15 0:00 ` John G. Volan
1997-09-14 0:00 ` Robert Dewar
1997-09-14 0:00 ` Robert Dewar
1997-09-10 0:00 ` Paul Johnson
1997-09-10 0:00 ` Matthew Heaney
1997-09-10 0:00 ` Darren New
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