🚀 go-pugleaf

How can I add a slot to a class? One solution is to redefine class but that
isn't terribly portable since it requires having the source definition
of the class. P. 203 of the AMOP describes how a slot instance can be
created, e.g., (make-instance  'clos:standard-slot-definition ...).
Then, the question becomes how can a slot instance be added to a given class
as if it were (almost) a re-definition of the class? Can this be done
in a portable manner? If not, I'd be equally interested in an
implementation-specific solution for Lucid 4.0.2 on sparc.

As an example, adding slots can be used to store additional state information
on objects so as to modify the behavior of an algorithm on those objects.
The algorithm modifications can be implemented as redefinitions of the
public methods of the algorithm so as to use the additional state information.
This approach seems to me elegant and portable. In terms of efficiency,
adding information on the object themselves seems to be the fastest way to
get at that information compared to other storage techniques such as lists,
arrays, or hash tables. 

-- 
Nicolas Rouquette
Artificial Intelligence Group
Jet Propulsion Laboratory
California Institute of Technology
4800 Oak Grove Drive
M/S 525-3660
Pasadena, CA 91109

phone: (818) 306-6171
fax:   (818) 306-6912
Email: rouquett@aig.jpl.nasa.gov