Stephane Ducasse <ducasse at iam.unibe.ch> wrote:

> If you look carefully all those implementors are in different 
> hierarchies.
> The idea was to avoid to have another method in Object
Given the same implementation is used and the same intent is in mind,
why one earth can we not just put it in Object? Any class that needs to
override or extend can do so. Putting the method in separate hierarchies
means that any new hierarchy needs yet another copy to be added - if
the implementor even knows about it.

Alternatively, get rid of the whole concept and go to either class-side
messages on SystemNavigation or istance side messages on a singleton
global SystemNavigator. The latter leaves open the possibility of having
further instances (or subclass instances) that can dealwith outside code
or images.

tim
--
Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
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