SM final tweaks (was Re: Trouble getting SqueakMap to work)

Avi Bryant avi at
Wed Jan 28 23:02:44 UTC 2004

On Jan 28, 2004, at 2:32 PM, goran.krampe at wrote:

> So the idea is to... add this "speaking UUID" as a field in SMPackage?
> Which is generated when the package is registered I assume.
> First - this "speaking UUID" would still not make packages renameable.
> Secondly - since this is so, the extra number at the end is hardly
> necessary since SM actually enforces the package name to be unique!
> So actually - what does this mean? What would happen if we simply used
> the package name (haven't looked at your code) with tricky chars 
> removed
> as shown above and perhaps also changed into lowercase (are all
> filesystems case sensitive?) and truncated at 31 chars?
> Well, theoretically the removal of tricky chars/truncation etc could
> make two packages end up with the same name.

I think you're misunderstanding.  Let me rephrase (my understanding of) 
the proposal:

Currently, to generate a new unique ID for a package you use Squeak's 
UUID class, which basically gives you a large random number.
What if, instead, you used a derivation of the original package name 
(whatever it is first registered with), truncated and with tricky 
characters removed, and with some extra numbers at the end to ensure 

This isn't a new field, or a new concept, or something that in any way 
changes any of the semantics of SM.  It's simply a new algorithm for 
generating the UUID for a package that happens to have the nice 
property that a human, looking at a UUID, may be able to guess which 
package it belongs to (although in some cases, especially after package 
renames, they may not be able to guess with 100% certainty).

This sounds like a pretty good idea to me.


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