From: card@syr.lmco.com
To: card@syr.lmco.com
Subject: Re: Visibility and access to "public" attributes
Date: 1997/09/02
Date: 1997-09-02T00:00:00+00:00 [thread overview]
Message-ID: <873212609.24297@dejanews.com> (raw)
I'd like to thank everyone who replied to my original
post RE: visibility of attributes.
I had wondered when/why one would make a class'
attributes read-only rather than hiding them altogether.
The answer to my question was provided by Peter Horan:
>One must export parameters and functions when they
>are needed to verify pre-conditions. This is an
>Eiffel validity requirement (VAPE). (I am reminded
>of keeping one's fingers crossed when making
>promises :-)). This does not apply to features in
>post-conditions and invariants, which may be more
>restrictive than the client needs without harm.
This makes sense. Since everything in a precondition
must be visible to a class's client(s), then the
client must be able to read the class's attributes
(features) if they are used in the precondition(s).
Thanks, Pete!
- Mike
---------------
Michael P. Card
Lockheed Martin Ocean, Radar and Sensor Systems Division
Syracuse, NY 13221
voice: (315)-456-3022 FAX: (315)-456-2414 e-mail:card@syr.lmco.com
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next reply other threads:[~1997-09-02 0:00 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
1997-09-02 0:00 card [this message]
-- strict thread matches above, loose matches on Subject: below --
1997-08-29 0:00 Visibility and access to "public" attributes card
1997-08-29 0:00 ` Patrick Doyle
[not found] ` <JSA.97Aug29190453@alexandria.organon.com>
1997-08-30 0:00 ` Patrick Doyle
1997-08-30 0:00 ` Jon S Anthony
1997-09-01 0:00 ` Patrick Doyle
1997-08-30 0:00 ` Darren New
1997-09-02 0:00 ` Don Harrison
1997-09-02 0:00 ` Don Harrison
1997-09-02 0:00 ` Gavin Collings
1997-09-02 0:00 ` Patrick Doyle
1997-09-02 0:00 ` Nick Leaton
1997-09-02 0:00 ` Gavin Collings
1997-09-03 0:00 ` Don Harrison
1997-09-05 0:00 ` Nick Leaton
[not found] ` <01bcba0e$418f7380$2001df0a@gavinspc>
1997-09-05 0:00 ` Nick Leaton
1997-09-05 0:00 ` Patrick Doyle
1997-09-02 0:00 ` Jon S Anthony
1997-09-02 0:00 ` Peter Horan
1997-08-29 0:00 card
1997-08-29 0:00 ` Ted Velkoff
1997-08-30 0:00 ` Patrick Doyle
1997-08-30 0:00 ` Darren New
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