Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!think.com!barmar
From: barmar@think.com (Barry Margolin)
Newsgroups: comp.lang.clos
Subject: Re: Is CLOS Object-Oriented ???
Keywords: CLOS, dynamic binding, setf, Flavors
Message-ID: <1990Nov24.235733.29577@Think.COM>
Date: 24 Nov 90 23:57:33 GMT
References: <1990Nov15.101847.26285@diku.dk> <3904@s3.ireq.hydro.qc.ca> <27443D49.2BE8@wilbur.coyote.trw.com>
Sender: news@Think.COM
Distribution: comp
Organization: Thinking Machines Corporation, Cambridge MA, USA
Lines: 25

In article <27443D49.2BE8@wilbur.coyote.trw.com> scott@wiley.UUCP (Scott Simpson) writes:
>I thought they were the same too until someone at work came up with
>this problem in Flavors:
>
>	(setf (send self (send button :slot-to-change)) value)
>
>What is happening is that (send button :slot-to-change) returns the
>name of a slot to change and that slot is changed to VALUE on the
>object SELF. How do you do this is CLOS?

Unfortunately, the above isn't valid Flavors code (at least as far as my
Symbolics machine is concerned).  When I try to macroexpand it I get told
that SETF of SEND requires the message name to be a constant.

IMHO, the closest translation is:

(funcall (slot-change-function button) self value)

The SLOT-CHANGE-FUNCTION generic function would generally return a function
of the form #'(setf <slot-name>).
--
Barry Margolin, Thinking Machines Corp.

barmar@think.com
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