2014-05-18 21:42 GMT+02:00 Johan Fabry <jfabry@dcc.uchile.cl>:

I understand, thanks for the info.

Let me simplify my question: Using slots is there a reasonably straightforward way for me to intercept variable accesses in all methods within a class?

Yes. This is easy to do with slots.��

��

Basically you need to define your own slot and mark the instance variables you want to intercept to use this specific slot (in your case, all the instance variables). Then all instance variable access will be compiled with your indirection.

This so that I can transparently redirect them to a dictionary lookup.

Yes, you can do that with slots.

However we were discussing about that recently with some VM guys, and this may be quite slow on our VM. One language that runs on our VM, NewSpeak, have similar features (indirection for all instance variable access) and it is difficult for them to have good performance. This dictionary lookup case is optimized in prototype-based language VMs (Self, Javascript). Usually for users it appears that there is an indirection with a dictionary, but the implementation does not rely on dictionary for performance.

Or am I going to have to override instVarNamed: and hope that works always?

I guess you will also have to override��instVarNamed: and/or instVarAt: if you want to catch reflexive instVar access.��

But that will never always work this method is only for reflective access.

On May 18, 2014, at 3:50 AM, Cl��ment Bera <bera.clement@gmail.com> wrote:

> Hello,
>
> Actually slots are introduced so we can use them the next Pharo iteration (Pharo 4). It is difficult to use as it is, you need to change a bit the compiler so that it asks the class slots for field access byte code generation (a field being typically an instance variable) and you also need to improve the class builder in a way that you would have a class template where you can set specific slot for each field. Then you can subclass slots and use them.
>
> So I'd say there's a few work to do to use them, but if someone do this work, it will be integrated for Pharo 4.
>
> Marcus, Camille, Martin, you know more than me about slots what do you think ?
>
>
> 2014-05-17 23:36 GMT+02:00 Johan Fabry <jfabry@dcc.uchile.cl>:
>
> +1 on the question actually, I think it may help with some hacky stuff that I am doing right now for my research :-)
>
> On May 17, 2014, at 5:10 PM, webwarrior <reg@webwarrior.ws> wrote:
>
> > So Pharo 3 is out, slots are listed in changelog, but how to use them? Any
> > examples (those in paper don't work)?
> >
> >
> >
> > --
> > View this message in context: http://forum.world.st/Slots-tp4679183p4759385.html
> > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.
> >
> >
>
>
>
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