The Join Point Model of DemeterF

A join point model for a dynamic AOP system consists of the set
of all join points, mechanisms to select sets of join points 
(called pointcuts), and mechanisms to specify behavior to
be executed at the join points selected by a pointcut (called advice).

The set of all join points are the object entry and exit points
of pure object traversals. For a specific program,
the join points are determined by the traversal control
(bypass and only fields for classes).
The pointcuts (sets of join points) are the combine
and update method signatures. Combine and update method signatures
include information about programmer controlled
traversal contexts which also influence the pointcuts.
Because of optional combine method arguments,
a pointcut may select a large number of join points.
The advice is given by the combine and update method
bodies.

The next join point to be executed is determined in two
steps. First the traversal advances in a DFS manner to the
next entry or exit join point. Multiple advice (update or
combine method bodies) might be available for that join point.
DemeterF executes only the most specific advice as in Socrates 
[Orleans AOSD 2002, Dissertation 2005).