On Sat, 22 Sep 2007 06:58:57 -0700, Kay Schluehr wrote:
> On Sep 22, 1:15 pm, Marc 'BlackJack' Rintsch <[EMAIL PROTECTED]> wrote:
>> On Sat, 22 Sep 2007 02:44:35 -0700, Kay Schluehr wrote:
>> > I checked out Io once and I disliked it. I expected Io's prototype OO
>> > being just a more flexible variant of class based OO but Io couples a
>> > prototype very closely to its offspring. When A produces B and A.f is
>> > modified after production of B also B.f is modified. A controls the
>> > state of B during the whole lifetime of B. I think parents shall not
>> > do this, not in real life and also not in programming language
>> > semantics.
>>
>> Well it's like Python: inherited slots (attributes) are looked up in the
>> ancestors. It should be easy to override `Object clone` in Io, so all
>> slots of the ancestor are shallow copied to the clone, but I guess this
>> might break existing code. At least for your own code you could introduce
>> a `realClone` slot.
>
> But in class based OO most relevant attributes are defined during
> object construction and they can't be simply changed by setting a
> class attribute. Later you often create new attributes as but on
> object level. You do not overuse the object/class relationship to
> broadcast changes to all objects.
You don't do this in Io either. It's really like Python in this respect.
There's an `init` slot that gets called by (the default) `clone` and you
set "instance attributes" there, for example mutables so they are not
shared by all clones.
Ciao,
Marc 'BlackJack' Rintsch
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