copy yourself ?
jan ziak
ziakjan at host.sk
Fri May 23 01:31:47 UTC 2003
yes we can look at the problem from the point you described below. i was just
waiting who will mention that viewpoint as the first.
On Fri, 23 May 2003 11:53:31 +1200 (NZST), Richard A. O'Keefe wrote
> "jan ziak" <ziakjan at host.sk> wrote:
> i would like to ask whether some squeaker has ever seen an
> object which is capable of copying itself.
>
> Why is that an interesting question? I have never seen a physical object
> that could add 1 to itself either. Smalltalk objects are not, for
> the most part, simulations of physical objects and there is no
> reason why they should go out of their way to imitate the
> limitations of physical objects.
>
> the point is that i do not
> believe that any object could copy itself.
>
> Von Neumann proved that it could.
>
my viewpoint on the self-reproduction is somewhat different - look in the
message in which i was writing about "intelligent glass".
> so why, in smalltalk, almost every object can copy itself when i
> send a message to it - it seems absurd to me. doesn't it also
> to you?
>
> Not in the least. Smalltalk objects can copy themselves because it
> is *useful* for them to be able to copy themselves. There isn't the
> slightest absurdity in being useful. On the contrary, what is
> EXTREMELY absurd is beating Smalltalk over the head because it has
> computational objects rather than physical objects.
>
> a second problem is that the copying process depends on
> particularities of situation in which someone or something
> want's to copy an object. copying is context dependent. so why
> has every object in smalltalk only one method for copying (well
> it has three types of copy-methods but the point is that the
> number and meaning of them fixed).
>
> Neither the number nor the meaning of copying methods is fixed.
> Any method can be overridden, and copying methods very often are.
> If you want to add a new #copyImprecisely method to Object,
> there isn't anything at all in Smalltalk to stop you.
>
> In short, the number and semantics of copying methods is whatever you
> want it to be.
>
> wouldn't it be more rational to have objects capable of
> constructing copies of objects?
>
> Clumsier, yes. More rational? In what conceivable way?
>
> One more time:
> COMPUTATIONAL OBJECTS ARE NOT PHYSICAL OBJECTS
> AND SHARE NEITHER THEIR STRENGTHS NOR THEIR LIMITATIONS.
> It is irrational to blame them for being different.
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