[self-interest] inheritance in Self

[Steve Dekorte]

On Wednesday, September 18, 2002, at 05:26  PM, David Ungar wrote:
> Not every object is guaranteed to respond to any particular message.
...
> Lookup loops *are* allowed in Self. The virtual machine simply stops 
> following parent links
> if it gets to an object it has already traversed.

Interesting. Do you use any tricks to make checking if the parent has 
already been searched on each lookup fast? The only thing that occurs to 
me is OR-ing each new parent pointer into variable and then doing an XOR 
with of this with the next parent pointer to see if a check is needed, 
but this becomes ineffective on long parent chains. Also, pointers are 
less spread out in copying garbage collectors like the one Self uses. (I 
guess if each object stored a hash value of itself, that could be used)

Thanks for the response,
Steve