Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!alberta!arcsun.arc.ab.ca!zero!mdb
From: mdb@arcsun.arc.ab.ca (Mark Brinsmead)
Newsgroups: comp.lang.clos
Subject: Defining SETF methods for CLOS methods
Message-ID: <1990Dec5.212406.20667@arc.ab.ca>
Date: 5 Dec 90 21:24:06 GMT
References: <9012051643.AA01507@zaphod.lanl.gov.lanl.gov> <19901205172442.3.BARMAR@OCCAM.THINK.COM>
Sender: nobody@arc.ab.ca (Absolutely Nobody)
Reply-To: mdb@arcsun.arc.ab.ca (Mark Brinsmead)
Followup-To: Naming: clos generics vs common lisp fns
Distribution: inet
Organization: Alberta Research Council
Lines: 21


   I have a (slightly) new question, which I think relates to the discussion
of naming conventions in CLOS:

   What is the "officially sanctioned" way of defining a setf method for ONE 
SPECIFIC method of a generic function?  My reading of the standards
implies that
something of the form:

   (defsetf (find-method <generic-function> (<specializers>)) ...)

ought to do it, but the version of PCL I am using (which I thought to be the
most recent!) does not seem to support FIND-METHOD, so I can't experiment.

   What I am trying to do (though its of little relevance) is to define a
write-once slot.  Defining it with a :ACCESSOR makes the slot just plain
writable; I want to allow writing ONLY as long as the slot-value is the
default, in this case, NIL.

--  Mark Brinsmead,		(mdb@arcsun.arc.ab.ca)
    Alberta Research Council


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