class, prototype, meta

John Albert Fehr jfehr at
Sun Mar 1 22:02:37 UTC 1998

wirth at wrote:
> While we're on non-CS points of view, let me ask a new question about
> method bindings.  I'm really interested in biological analogs (and was much
> taken by the ones you mentioned in your OOPSLA keynote).  I've been trying
> to figure out how one might do method dispatching for prototypes that are
> floating around a distributed, sometimes-connected environment (as span the
> set of electronic gadgets I have in my pocket, briefcase, etc.).  Cells
> have receptors on their cell walls that signal what messages (proteins)
> they can receive.  Can we use a similar mechanism for objects?  (The answer
> to which leads to more questions about where the methods are stored, how
> they're inherited, etc.  The fantastic redundancy of having the full
> "source code" in the DNA in each cell is a marvelous thing.)  Comments?
> Pointers to other writings on computational vs. biological systems?
> Mike

i don't have any "pointers to other writings" but i want to comment.  
i liked what Alan had to say about the region between a prototype and 
a "kind"  -- that something starts out as a sketch and evolves into a 
"kind of" something.  i've wondered if a behavior for a prototypes or 
classes couldn't die if unused, like entrophy.  one could prototype a 
method definition, allow it to keep track of its invocations and 
versions, and the most frequently sent definitions could persist 
across the temporal prototype-to-kind evolution phase.  those methods
definitions that are unsent would either die or remain in the prototype 
for further refinement -- excluded from the emerging "kind."  
furthermore, in an local image, unwanted (unsent) behavior could be 
treated like unreferenced objects -- eligible for garbage collection.  
if the behavior is ever needed, its definition might be fetched from 
another local image, compiled for that platform and evaluated -- as 
in a set of local images "floating around a distributed, sometimes-
connected environment" or a kind of cyber-image.  one could measure 
when a prototype is a more-stable "kind" by the frequencies of its 
instantiation and the utilization of its respective behaviors.

excuse me if this has all been discussed. i just subscribed to this 
forum.  i liked your question about method bindings and wondered if 
dispatching might be assisted by somehow tracking behavior 
invocation, -John F.

John Albert Fehr
Ranch to Market, Inc.
PO Box 162404
Austin, Texas  78716-2404
(512) 472-6726
jfehr at

More information about the Squeak-dev mailing list