From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Ensuring postconditions in the face of exceptions
Date: Tue, 16 Mar 2010 18:23:16 -0500
Date: 2010-03-16T18:23:16-05:00 [thread overview]
Message-ID: <hnp3t6$mfc$1@munin.nbi.dk> (raw)
In-Reply-To: wcciq8wxpkv.fsf@shell01.TheWorld.com
"Robert A Duff" <bobduff@shell01.TheWorld.com> wrote in message
news:wcciq8wxpkv.fsf@shell01.TheWorld.com...
> "Randy Brukardt" <randy@rrsoftware.com> writes:
...
>> Repeat after me: "limited" is a property of a view! It's not constant for
>> a
>> particular type! That's a common mistake that even those of us on the ARG
>> make from time-to-time.
>
> I don't understand why the definition of "by reference" is subtly
> different from the definition of "immutably limited".
Two obvious reasons: "by-reference" predates "immutably limited" by more
than 10 years, and besides there are non-limited types where are
"by-reference" (non-limited tagged types). The latter also means that types
with a component of a non-limited tagged type are "by-reference" as well.
Finally (OK, I can't count), "by-reference" breaks privacy (thus only
dynamic rules ought to depend on it; legality rules should never depend on
the contents of the private part), while "immutably limited" doesn't break
privacy and thus can be used in legality rules. "Immutably limited" is a
direct property; it doesn't depend on type of components.
The net effect is that there isn't much similarity between the two concepts,
nor their use.
Randy.
next prev parent reply other threads:[~2010-03-16 23:23 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-12 9:13 Ensuring postconditions in the face of exceptions Ludovic Brenta
2010-03-12 9:24 ` Ludovic Brenta
2010-03-12 9:29 ` Niklas Holsti
2010-03-12 11:08 ` Ludovic Brenta
2010-03-12 14:00 ` Jeffrey R. Carter
2010-03-13 3:15 ` Randy Brukardt
2010-03-13 15:14 ` Robert A Duff
2010-03-16 3:13 ` Randy Brukardt
2010-03-16 15:18 ` Robert A Duff
2010-03-16 19:00 ` Adam Beneschan
2010-03-16 20:04 ` Robert A Duff
2010-03-16 23:23 ` Randy Brukardt [this message]
2010-03-13 17:34 ` Jeffrey R. Carter
2010-03-13 7:54 ` Stephen Leake
[not found] ` <ruqub2y84rqj.179q01lxzgatj$.dlg@40tude.net>
2010-03-13 19:33 ` Georg Bauhaus
2010-03-14 14:05 ` Alex Mentis
2010-03-14 14:21 ` Ludovic Brenta
2010-03-14 15:12 ` Alex Mentis
2010-03-15 9:14 ` Ludovic Brenta
2010-03-15 11:05 ` cjpsimon
2010-03-15 13:04 ` Ludovic Brenta
2010-03-15 14:16 ` J-P. Rosen
2010-03-15 19:14 ` Jeffrey R. Carter
2010-03-16 19:25 ` Robert Matthews
2010-03-14 15:38 ` Robert A Duff
2010-03-15 8:54 ` Ludovic Brenta
2010-03-15 16:44 ` Robert A Duff
2010-03-15 17:33 ` Ludovic Brenta
2010-03-15 18:36 ` Robert A Duff
2010-03-14 18:57 ` Jeffrey R. Carter
2010-03-15 8:56 ` Ludovic Brenta
2010-03-15 11:04 ` AdaMagica
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