[self-interest] A question about method slots

Jecel Assumpcao Jr. jecel at merlintec.com
Mon Mar 10 22:20:15 UTC 2014


Michael,

> If you want to say, that the statement,
> 
> "if you clone an object, the original becomes the parent of the clone."
> 
> is not just "rumours", but right in some way, I would like to understand 
> this better.

I am pretty sure David is saying that the statement is wrong. It isn't
very hard to see where the idea came from. If you first read "Using
Prototypical Objects to Implement Shared Behavior in Object-Oriented
Systems" presented by Henry Lieberman at OOPSLA 1986:

http://web.media.mit.edu/~lieber/Lieberary/OOP/Delegation/Delegation.htm
l

and then you have that very much in mind as you read "Self: The Power of
Simplicity" presented by David Ungar and Randall Smith at the next
OOPSLA:

http://bibliography.selflanguage.org/self-power.html

it is *very* easy to see stuff in the paper that really isn't there. You
have to remember that this is the extent of the experience that most
people who discuss Self have had with the language. On top of that we
had "SELF and the Origins of NewtonScript" by Walter Smith (Originally
published in PIE Developers  magazine, July 1994):

http://waltersmith.us/newton/SELF%20and%20the%20Origins%20of%20NewtonScr
ipt.pdf

which reinforced the idea that the Lieberman model in NewtonScript had
come from Self. I know that Steve Dekorte thought so for quite a while
after having created Io based on NewtonScript. And people often look at
the title "Parents are Shared Parts: Inheritance and Encapsulation in
Self" by Craig Chambers, David Ungar, Bay-Wei Chang and Urs Hölzle (Lisp
and Symbolic Computation 4(3), Kluwer Academic Publishers, June, 1991):

http://bibliography.selflanguage.org/parents-shared-parts.html

without reading the actual paper (and often not even the abstract) and
it confirms their idea that Self uses the Lieberman differential
prototype model. But Self's model comes from ARK (The Alternate Reality
Kit by Randall Smith) instead where new objects are perfect clones of
their prototypes instead of empty children of the same:

http://www.open-video.org/details.php?videoid=8050

In short: it is reasonable that people think that in Self "if you clone
an object, the original becomes the parent of the clone." but they are
wrong.

-- Jecel




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