what is Image?

Stef

On Aug 9, 2008, at 11:41 AM, Tony Garnock-Jones wrote:

> Hi,
>
> K. K. Subramaniam wrote:
>> My interest got piqued because if the primal image is so complex  
>> that it requires jiggery pokery perhaps it is time to apply Occam's  
>> razor to it. Transmutation (aka bootstrapping) from one type of  
>> system into Smalltalk should not be so complex that SystemTracer  
>> remains only source of information even after nine years.
>
> Have a look at the bootstrapping process for Slate, starting perhaps  
> with http://slate.tunes.org/repos/stable/src/mobius/vm/ 
> bootstrap.slate. The fact that the program is written in Slate does  
> not detract from what the program does, which is (if I remember  
> rightly!) to build and serialise a model of an image that does not  
> rely on any characteristics of the host language.
>
> (Compare approaches to implementing call/return in simple  
> interpreters: you can use the host language's support for call and  
> return, by recursing into your evaluator in the host language, or  
> you can reify the stack, and so avoid requiring the host language to  
> even have call/return semantics. Similarly, Slate reifies the image  
> being constructed, so doesn't depend on being image-based itself.)
>
> (Also, I had a go at the same thing myself: See the definition of  
> (bootstrap-image!) in http://www.eighty-twenty.org/~tonyg/Darcs/smalltalk-tng/r1/kernel.scm 
> . This is a Scheme system implementing an image-based Slate-like  
> language.)
>
> Regards,
>  Tony
>
>