[cells-devel] Family Registry ? What for ?

Kenny Tilton kennytilton at optonline.net
Thu Oct 23 12:38:09 UTC 2008


Frank Goenninger wrote:
> While inspecting a model I saw the registry? slot - but no registry  
> being assigned ...

I have this in my family.lisp:

(defmethod initialize-instance :after ((self family) &key)
   (when (registry? self)
     (setf (registry self) (make-hash-table :test 'eq))))

No?

> Which lead to an assertion failure afterwards.

Where exactly?

> So:  
> What for is the registry mechanism?

Actually Peter H rolled something similar doing his project and I had 
been fighting thru a lot of issues where one instance was looking for 
another by name and it got tricky because everyone was coming into or 
going out of existence and did not exist yet or any longer and I decided 
to see if simply registering a name-model pair in a hash table right at 
initialize-instance time (vs md-awaken even) would work better than 
fm-other which navigates the family tree to find things.

It does help, but I do not use it for normal lookups, just the ones that 
do not play well with the normal scheme.

cheers,

ken




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