[Traits] Namespaces(environments?), SystemChangeNotifier, ...

> List,
>
> for a new project we plan to create a namespace which can and will  
> have names clashing with existing global names like Object[tm] and  
> Process[tm]. All behavior will be specified in form of Traits (for  
> the immediate future only classTraits).
>
> We've looked around in the Traits implementation [3.9a] and found a  
> good namespace separation example, [self environment organization],  
> but there also is [SystemChangeNotifier uniqueInstance] which seems  
> to know nothing about possible name clashes.
>
> What is the status, are the plans for having 100%[tm] separated  
> namespaces? Google found
> - http://lists.squeakfoundation.org/pipermail/squeak-dev/2004- 
> December/085761.html
> was there anything else we should take care of?
>
> The new name space we have in mind derives from ontologies and we  
> don't want to force users of an ontology namespace to prefix or  
> suffix any names/identifiers.
>
> And while we are at it, how should an object (say, a Class) use  
> objects from another namespace (say, a Traits), and what about  
> namespace separation in #definitionST80.
>
> But perhaps there are other and/or better ideas on how to separate  
> namespaces in Squeak, suggestions and/or experience, all appreciated.
>
> /Klaus
>
> P.S. Of course we already have some ideas (and working code  
> examples) on how to address these issues but would naturally like  
> to hear voices from the community.
>
>

> List,
>
> for a new project we plan to create a namespace which can and will  
> have names clashing with existing global names like Object[tm] and  
> Process[tm]. All behavior will be specified in form of Traits (for  
> the immediate future only classTraits).
>
> We've looked around in the Traits implementation [3.9a] and found a  
> good namespace separation example, [self environment organization],  
> but there also is [SystemChangeNotifier uniqueInstance] which seems  
> to know nothing about possible name clashes.
>
> What is the status, are the plans for having 100%[tm] separated  
> namespaces? Google found
> - http://lists.squeakfoundation.org/pipermail/squeak-dev/2004- 
> December/085761.html
> was there anything else we should take care of?
>
> The new name space we have in mind derives from ontologies and we  
> don't want to force users of an ontology namespace to prefix or  
> suffix any names/identifiers.
>
> And while we are at it, how should an object (say, a Class) use  
> objects from another namespace (say, a Traits), and what about  
> namespace separation in #definitionST80.
>
> But perhaps there are other and/or better ideas on how to separate  
> namespaces in Squeak, suggestions and/or experience, all appreciated.
>
> /Klaus
>
> P.S. Of course we already have some ideas (and working code  
> examples) on how to address these issues but would naturally like  
> to hear voices from the community.
>
>

> ...
> My Namespaces code (hmmm, did I update it on SM? Nope, doesn't look that
> way, sorry, will put it up there) was refreshed to work in 3.9 when I
> was in Brussels recently and presented it to the people attending that
> Smalltalk party. Other people attending can comment on it - but
> unfortunately I managed to break the code right before the talk so I
> couldn't demo it - but it worked 30 minutes later when I discovered what
> I had done. ;)
>
> I very much want to make that code as good as possible so that the
> community can decide if we want to use it or not. I personally think it
> is a simple and very nice way of dealing with the problem. There are
> also numerous writeups about it, the latest here:
>
> http://swiki.krampe.se/gohu/32

> Hi Roel,
>
> on Mon, 24 Apr 2006 17:48:27 +0200, you wrote:
>
>> Hello,
>>
>> I am maintaining the SystemChangeNotifier, so I am interested in  
>> the discussion.
>
> Thank you for taking care!
>
>> Could you elaborate a bit more on SystemChangeNotifier and name  
>> clashes, since I did not quite follow you there.
>
> Now that I reread my posting I see that I should have written  
> "namespace separation" instead of "name clashes" when I mentioned  
> SystemChangeNotifier. Apologies! But anyways, here is how we  
> stumbled on SystemChangeNotifier.
>
> We checked the classes in System-Change Notification (and also  
> class ModifiedTraitDefinitionEvent) to find out what happens when  
> the namespace of an entity (Class or Traits) is changed. We  
> couldn't find evidence that such a change is recognized. So  
> possibly [SystemChangeNotifier uniqueInstance allSystemEvents] and  
> #notify:ofAllSystemChangesUsing: do not handle such a situation?  
> Perhaps [oldItem environment] and [newItem environment] would fit  
> the bill, dunno. In any case, namespace changes (of classes and/or  
> traits) seem not to be captured nor reported.
>
> There currently is no urgence for system change notification to  
> take care of namespace changes, we can live with the "manual" design
> +development rule: take care with namespaces and system change  
> notification.
>
> But for (multiple) namespaces to be useful painlessly, sooner or  
> later support from system change notification is neccessary.
>
> Hope this clarifies a bit.
>
> /Klaus
>
>