Hi john

What is also really nice is the separation of the reflective aspect into
separate objects called mirror.
This way you get smaller classes and clear identifiable use of refelctive
facilities.

They have a libraries of low-level mirrors which reify the VM interpretation
of structure at the level of Smalltalk. These low-level mirror can then be
used to for example represent the stack and create a **synchroinized**
debugger.

For example a domain class should not make explicit reference to a mirror.
Hence the domain class can be shipped without all the reflective aspects
when not needed

so Object does not define instVarAt but a low-level mirror does it.
and we can still do

InspectoorMirror on: anObject in which lowlevel mirror will interpret the
object structure. 

So this is a really nice decomposition and recomposition of reflective
aspects. However, they do not provide a MOP just a separation of reflective
aspects. A MOP could be built on top of the mirrors.

This is a really exciting model.
Gilad promises to write a chapter on Animoprhic Smalltalk for the collective
Smalltalk Technology book.

So we will see. 


on 7/17/01 7:04 PM, John.Maloney at disney.com at John.Maloney at disney.com
wrote:

> The Animorphic Smalltalk VM was very high performance. It ran on
> Intel (Win95, I think). My guess is that it would be a fair amount of
> work to port it, since I think they used some assembly code to get
> speed and, of course, it includes a dynamic translator (JIT).
> 
> Their Smalltalk image and class hierarchy was quite interesting. It
> had a type checker and type inferencing system based on abstract
> interfaces ("protocols"), but the type checking was optional. You
> could write code without type declarations during exploratory
> programming, then fill in the declarations later.
> 
> -- John
> 
> 
> At 11:14 PM +0200 7/16/01, Stephane Ducasse wrote:
>> on 7/16/01 12:58 PM, Joern Eyrich at Joern.Eyrich at brokat.com wrote:
>> 
>>> are there any news about this yet? like, *how* soon?
>>> 
>>> Stephane Ducasse wrote:
>>>> 
>>>> Hi
>>>> 
>>>> Gilad Bracha from Sun told me that the animorphic VM and Smalltalk code
>>>> they
>>>> made just before Java went breaking research at Sun will be available soon.
>>>> 
>>>> In this code they introduced mixins (which I think are interested but need
>>>> some extra work) and mirrors that encapsulated reflective aspects to be
>>>> composable.
>>>> 
>>>> So I'm really eager to play with it.
>>>> 
>>>> Stef
>> 
>> Gilad said for the end of the summer but you can ask him directly
>> gilad.bracha at eng.sun.com
>> 
>> stef
> 
> 
> 
> 
>