Parsing Smalltalk with SmaCC

Bergel, Alexandre bergel at
Fri Jun 29 13:28:42 UTC 2007

Thanks Ralph for this detailed explanation.


On 29 Jun 2007, at 13:42, Ralph Johnson wrote:

> SquekMap and Package Universe differ in at least two ways.
> The one that people notice immediately is that PU knows the
> prerequisites for a package.  Thus, when you load a package in PU, you
> load all the packages that it depends on.  This makes it much easier
> to use than SM.  SM ought to be changed to do the same, and if it
> doesn't change then in my opinion it is likely to be abandoned.
> The second major difference is that there is one SqueakMap, and it
> tries to hold everything.  There can be many databases for PU, on the
> other hand.  One PU can include another.  Each PU is supposed to have
> someone who oversees it and who makes sure that everything goes
> together.  However, this last feature hasn't been used much.  There
> was a PU for 3.9 and there is a different one for 3.10.  But lots of
> different people stick stuff in the 3.10 "universe", and so it can
> take awhile before we discover that two packages don't work together.
> It is useful to have a complete list of packages.  It would be a shame
> to abandon that feature of SM.  Most of the time, however, I only want
> packages that are known to work with my current version.
> SM has some other features that PU doesn't, such as recording license
> info.  PU can't uninstall a package, and I think SM allows this.  It
> would be nice if PU added these features.  But the strength of PU is
> that everything is supposed to work together, so PU is fundamentally
> at odds with the requirement to find every existing package.
> Edgar said that the 3.10 release team is going to drop SM.  That is
> not entirely true.  We have been moving packages out of the image, and
> PU makes that easier.  When we move a package out of the image, we
> move it into PU.  So, the plan is to move SM from the image to PU.  It
> will still be available.
> The names of SM and PU seems wierd to me.  Sicne SM tries to include
> everything, it should have been called "Squeak Universe".  Since PU
> only contains packages that work toether, it shouldn't have been
> called "universe".  Perhaps "galaxy", since there are many galaxies
> but only one universe.
> -Ralph

Alexandre Bergel

More information about the Squeak-dev mailing list