Josh Flowers wrote:
> 
> What about something similar to Catagories in Objective-C?  Packages can add/change
> messages to base classes, but not variables, and those messages are invisible to other
> packages.
> 
> If HTMLPackage adds an asHtml method to String, a subclass (or a new Catagory) of String
> is created, and put in the HTMLPackage dictionary.  When an object within the HTMLPackage
> calls asHtml on a String the message is understood, but when the string object is
> referenced from another package, the asHtml message would no longer be valid.
> 
> Usual new user disclaimer.

Parcels within VisualWorks are similar to this, but still run into problems
as there is no mechanism within VisualWorks ( that I'm aware of ) to resolve
overlapping changes, other than "last loaded wins".  Obviously, that won't
work in every case.

Parcels do load and unload cleanly when properly built, and are otherwise a
very nice feature.

les