Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!cs.utexas.edu!rutgers!bellcore!pc@flash.bellcore.com
From: pc@flash.bellcore.com
Newsgroups: comp.lang.lisp
Subject: updating random slots in (say) defstruct
Message-ID: <18963@bellcore.bellcore.com>
Date: 15 Jan 90 15:49:10 GMT
Sender: news@bellcore.bellcore.com
Reply-To: pc@flash.bellcore.com
Organization: Bellcore
Lines: 27

> In article <18837@bellcore.bellcore.com> pc@flash.bellcore.com writes:
> >There appears to be no Common LISP way to similarly update a random
> >slot.  The best one can do seems to be:
> 
> You can do
> 
> (setq updater-function #'(lambda (object value)
> 			   (setf (test-one object) value)))
> 
> (funcall updater-function instance value)
> 

Yes, that's so.  But given a defstruct with 50 slots, i must define an
updator function for each, which seems wasteful, given that the DEFSTRUCT
has already defined one.

> In ANSI Common Lisp you'll be able to use #'(setf test-one) to access the
> updater function directly.


Ah, now this is closer to what i was looking for.  But what i want to
do, is define a SETFable function created with (INTERN (string-append
<defstruct-name> "-" <slot-name>)).  Perhaps i really have to throw the
whole expression i've consed up to EVAL.  But that really is a bit
gross.

Peter Clitherow