[cells-devel] Re: [cello-devel] Constructor syntax

[Thomas F. Burdick]

Kenny Tilton writes:

 > Thomas F. Burdick wrote:
 >
 > >At this point, something should handle the UNBOUND-CELL error, and
 > >make SUM unbound.
 >
 > well, I always get a kick out of digging and digging and finally there 
 > it is in all its simplicity:
 > 
 >     (funcall (c-rule c) self)
 > 
 > ...or something like that. So that would be where the trap for 
 > unbounditude would go.
 > 
 > >  Now, if I call ADDER-SUM, it should kick off SUM's
 > >rule again,..
 >
 > Why? rules get run when dependencies change or the state is unknown 
 > (only after make-instance, except for lazy cells which have been 
 > invalidated but not recalculated). The unbounditude is effectively a 
 > cached result, so there is no need to kick off the rule.

Good point.  I was thinking we'd kick of the rule here, so the user
could see which slot was ultimately responsible for the unbound error
-- but we can just cache that information, hell, cache the condition
itself, and signal it when needed.