On Sat, Feb 09, 2013 at 11:51:21PM +0000, Frank Shearar wrote:
> In the interests of revisiting Pavel Krivanek's work, and a long term
> goal of this community, I thought I'd use the Dependency Browser and
> dig out interpackage dependencies.
> 
> By scraping the DependencyBrowser's contents together with a bit of UI
> scripting I've constructed a dotfile of Trunk (attached). Turning this
> into a PNG results in an 11MB image! [1] Nodes near the top are nodes
> that aren't used by many things.
> 
> For instance, ReleaseBuilder's right at the top because nothing depends on it.
> 
> One thing to note is that XML-Parser and Nebraska are only used by
> Universes, and that Universes isn't used by anything else.
> 
> It occurs to me that we could thus remove these 3 packages from trunk
> and add the loading of these to ReleaseBuilderFor4dot5 [2], and still
> end up with a 4.5 that while apparently unchanged, actually has a
> smaller core.
> 
> What do you think of trying this out as an experiment? How would we
> unload these packages? (I should note: I've nothing against these
> packages. They're just packages that aren't woven into the guts of the
> image, and are thus easily removable.)

I would prefer to see the experiment focus on *reloadable* packages,
in the sense of SmalltalkImage>>unloadAllKnownPackages, where the
unloaded packages are supposedly distinct enough that they can be
reloaded after having been removed from the image. Success would
be defined as being able to unload a package, reload it, and verify
that the image is equivalent to what you started with. I think that
the packages you identified are probably good candidates for an initial
experiment with this.

If we had some way to actually test that reloadable packages stay
that way over time, presumably with the help of Jenkins, it would be
a really good thing. I'm not entirely sure how to test for this, but
it would be very worthwhile if someone could figure it out. I think
that a verifiable set of truly reloadable packages would go a long
way toward improving modularity.

I'm not so keen on the idea of just unloading things without some
mechanism to verify that they stay reloadable. That's a fast track
to bit rot.

> 
> frank
> 
> [1] If you have dot installed, `dot -Tpng -o trunk-deps.dot
> trunk-deps.png` will do the trick.

I think you meant 'dot -Tpng -o trunk-deps.png trunk-deps.dot'.
Nice picture :)


> [2] Installer squeak
> 	package: 'trunk';
> 	install: '39Deprecated-ar.19';
> 	install: '311Deprecated-nice.2';
> 	install: 'XML-Parser-ael.35';
> 	install: 'Nebraska-ul.35';
> 	install: 'Universes-nice.45'.


>