Article View: comp.lang.clos
Article #424accessing clos objects
From: Jon L White
Date: Thu, 14 Feb 1991 00:33
Date: Thu, 14 Feb 1991 00:33
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re: Note that in this example the INSTANCES slot will be shared by all
subclasses of ENUMERATION-MIXIN, and so will contain all instances of
all subclasses. In the context of this discussion this is probably not
what is desired. More likely, you would like (CLASS-INSTANCES <some-x>)
to return a list of all instances of class X and only instances of class
X. . . .
Good point. In fact, there is even a bit of terminological confusion
about what "instance" means. I _think_ that amongst some subset of
of CLOS'ers, we've agreed to use "direct instance" to mean what you
are referring to here; to use "indirect instance" to mean "direct
instance of a subclass" (or, ocasionally "derived instance", following
the C++ inspired terms of "base class" and "derived class"); and to
admit that an unqualified "instance" is ambiguous in that different
sectors of the community use it differently.
So, independently of the design issues you bring up, _I_ would expect to
see the slot named INSTANCES pointing to the union of all direct and
derived instances, and to see the slot named DIRECT-INSTANCES used for
the more immediate set. Incidentally, I note that Skip Egdorf did
follow this nomenclature in his recent mesages wherein he presesented
the generic function CLASS-DIRECT-INSTANCES.
One more thing -- sigh -- it seems that the mailer has lost my copy
of the message I sent out:
> Date: Tue, 12 Feb 91 14:48:41 PST
> From: Jon L White <jonl@lucid.COM>
You don't suppose you could forward me a copy?
-- JonL --
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!magnus.ircc.ohio-state.edu!tut.cis.ohio-state.edu!LUCID.COM!jonl From: jonl@LUCID.COM (Jon L White) Newsgroups: comp.lang.clos Subject: accessing clos objects Message-ID: <9102140033.AA23240@kolyma> Date: 14 Feb 91 00:33:48 GMT References: <2875458505-365193@Gilgamesh> Sender: welch@tut.cis.ohio-state.edu Distribution: inet Organization: CommonLoops Lines: 36