On Jan 24, 2006, at 10:49 AM, Marcin MielÅ¼yÅ?ski wrote:
What exactly do you mean by eigenclass? is it the same as an
anonymous class created by class<<obj syntax?
Yes (but actually I haven’t found any eigenclass definintions on
the web, not even on http://eigenclass.org/)
(class <<target; self; end)
evaluates to an instance of Class that has the unique
property that its instance methods are only available to
the object referenced by ‘target’.
Traditionally this class has been called target’s ‘singleton class’.
There has been some community frustration with that particular name
due to other meanings of ‘singleton’ as well as the existence in the
standard library of a class with the name ‘Singleton’; both of which
have nothing to do with the expression above. Matz has also hinted
that this feature might not be class based in the future, which would of
course make the term ‘singleton class’ even more confusing. So
this very useful concept floats around in nomenclature-limbo at the
Alternative terms have been suggested. Eigenclass is one of them.