[squeak-dev] Re: Meeting Report for 8/18/2010

Juan Vuletich juan at jvuletich.org
Tue Aug 24 11:53:17 UTC 2010


Andreas Raab wrote:
> On 8/23/2010 4:28 AM, Pavel Krivanek wrote:
>> Hi Andreas,
>>
>> the latest KernelImage based on Squeak 3.10 is here:
>> http://comtalk.cz/public/pub/KernelImage/current/
>> I continuously compared the image to Squeak and commented the changes.
>> For more information see http://www.squeaksource.com/KernelImage.html.
>
> Thanks Pavel, that's *hugely* helpful. I'm seriously wondering how I 
> could have missed that - the only explanation I have is that this must 
> have happened when I didn't pay any attention to Squeak :-)
>
> One thing that I'm not sure about is how to interpret the scripts at 
> the above URL - are they used to create the package structure in the 
> KernelImage repository or are they for something different?
>
> In any case, I think that's very good starting point. I'm curious, 
> Juan, how does that stack up to Cuis? Is that similar to the structure 
> you've ended up with or very different?

I have only looked at Pavel's work very briefly, so my comments might be 
wrong. The main focus of KernelImage is about modularization, while the 
main focus of Cuis is cleaning.

This means that Cuis doesn't provide a set of packages to build a 
"bigger image", and therefore doesn't have a clear structure of how 
those packages might be like. On the other hand, it means that 
KernelImage doesn't provide simple, efficient, clean code. I mean, with 
KernelImage you have either just a headless system, or a a bigger image, 
with more stuff loaded, but without significant improvements in code 
quality.

It seems that there is a lot to learn from KernelImage about the 
modularization of the image. If you want to start with a headless image, 
may be you can even start building on top of it.

Cuis is useful if you want to start with a complete, working ST-80 like 
system, including a GUI, dev tools, etc.

As a side note, headless KernelImage is about 2Mb. Cuis (reducing fonts 
to a usable minimum) is about 2.9Mb. This might suggest that Cuis has 
bigger "bang for the buck", and this could mean simpler, better code. 
This would be consistent with the huge amount of hours I've spent 
cleaning Cuis. Somebody could try to do a fair comparison between them, 
though. When I realized that KernelImage is headless, and therefore, not 
a easy to browse and study, I just didn't spend any more time on it.

>> There are several possible approaches:
>> - take the original KernelImage and adopt it for the latest Squeak. It
>> should be quite easy.
>> - do the similar remodularization and patches as the Pharo did. The
>> package structure of Pharo and Squeak then will be very similar.
>> - Pharo did a lot of important work on the cleanup of the system, it
>> has wider and motivated community of developers and its goals are
>> subset of goals of Squeak. What about to use whole Pharo as the basic
>> system for Squeak and let Pharo people to finish its modularization
>> and focus on tasks important for Squeak? Give me week or two and I
>> will show you that it's possible to load EToys and other Squeak
>> specific stuff to Pharo...
>
> I'm sure it's possible given enough effort. But it won't matter. The 
> issue isn't technical, the rift between Squeak and Pharo is something 
> that is the result of both personal as well philosophical differences. 
> Contrary to which Cuis is much closer to Squeak; not only is Juan a 
> Squeak board member, but the idea of having a system that a single 
> person can understand is dear to all of us, I think :-)
>
> Cheers,
>   - Andreas

I fully agree, but I see a clear technical issue. Current Pharo has too 
much 'optional stuff' to be considered the basic system. If the Pharo 
modularization efforts lead to a much smaller kernel (perhaps the size 
of Cuis or KernelImage), then that could be the basic system.

So it seems that Squeak and Pharo might be walking a similar path to 
system modularization. So, personal and social issues aside, what would 
be nice is some form of cooperation between those efforts.

Cheers,
Juan Vuletich



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