LISP X based toolkits

[Haruyuki Kawabe <kawabe@etl.jp>]

   >Sender: KK@sierra.csc.ti.com
   >Date: Thu, 6 Oct 88  19:38:16 CDT
   >From: Kerry Kimbrough <Kimbrough@dsg.csc.ti.com>
   >
   >One rightful objection to the way CLUE works is that invoking callbacks involves
   >a look-up that is a lot like method dispatch, so why does it have to be
   >different?  Another approach has recently been pointed out to me.  Instead of
   >looking up a function associated with a 'callback-name, the contact calls the
   >generic function 'callback-name.  The application programmer defines a
   >instance-specific method for 'callback-name by using an (eql <instance>)
   >specializer.  The method would be created dynamically by using something like
   >(make-instance 'standard-method ...  :function #'application-function-closure
   >...) and add-method. Why didn't we do this? It didn't occur to us until now! Hey,
   >10-4 on that CLOS learning curve.  Anyway, I'm looking into this, and I'd
   >appreciate any advice on its pro's and con's.

But it seems to me that it is too heavyin most implementations to add or remove methods at
run time because of re-hashing of a method table or
similar things in order to speed up of generic-function callings,
 Another approach is adding methods using WITH-ADDED-METHODS (or
GENERIC-FLET), but they are only available lexically.