Re: [Pharo-users] adding instance variables (data) to the Object class

[Petr Fischer via Pharo-users]

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It looks like I can't simply add statefull trait to the Object like this:

ProtoObject subclass: #Object
        uses: TMyTrait
        instanceVariableNames: ''
        classVariableNames: 'DependentsFields'
        package: 'Kernel-Objects'

After this, Pharo 7 VM goes to 100% of CPU usage, several GB of RAM usage and 
then crash.

Or... what do you mean by "talents"? I found also this: 
https://github.com/tesonep/pharo-talents

Thanks, pf


> Talents with statefull traits will help you
> 
> пт, 7 сент. 2018 г., 9:08 Marcus Denker <marcus.den...@inria.fr>:
> 
> >
> >
> > On 6 Sep 2018, at 23:35, Petr Fischer via Pharo-users <
> > pharo-users@lists.pharo.org> wrote:
> >
> >
> > *From: *Petr Fischer <petr.fisc...@me.com>
> > *Subject: **adding instance variables (data) to the Object class*
> > *Date: *6 September 2018 at 23:35:26 CEST
> > *To: *pharo-users@lists.pharo.org
> >
> >
> > Hello! Weird question: why I can't add instance variables to the Object
> > class (for example "oid" or something else)? Is it due to some internal
> > (and different) VM "class layouts"?
> >
> > Or - can I inject my own information to all existing objects (any class)?
> >
> >
> > Behavior is a subclass of Object, too. So that means that you would add a
> > ivar to all the classes, but for the VM an object can only be a class that
> > has three ivars, and those
> > are accessed by offset. So if you add an ivar, you shift the offset —>
> > problem.
> >
> > As for “I want to add object specific state”: it would be nice to add an
> > easy to use (and efficient) mechanism to do it.
> >
> > Marcus
> >

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