Re: appearance problem with LISTs [really handles]

[Paul Burchard <burchard at horizon.gw.umn.edu>]

> I believe the appearance behavior is a "feature" of
> handles in general, not a problem with LISTs in
> particular.  I think that different instances of a handle
> can have different positions but cannot have different
> appearances.

Stuart already fixed this bug.  Handle instances can indeed have  
different appearances -- it was just failing for the specific  
construct {appearance{...}{:handle}}.  (You're right, though, it had  
nothing to do with LISTs.)

Normally, {appearance{...}X} can be optimized to use X's appearance  
structure, without destroying the referential transparency of OOGL,  
because X is a "value" which is never referenced anywhere else.   
However, this optimization fails in the case when X is of the form  
{:handle}.  In that case, {appearance{...}{:handle}} must explicitly  
create a new Geom, built hierarchically on top of the handle, with  
its own appearance struct.

PB