Hi I-Chen:

I am glad you have chosen the adapter bean project.
Below is an abstract description of your project.

-- Karl

Adapter Beans:

Abstract problem:

Input:
Class graph G with strategies S1 and S2 where S2 is a
refinement of S1.
Input object O for class graph G.
Output:
Traversal of O according to both S1 and S2. (According to S2 would be enough
because S2 is a refinement of S1).

(See paper with Boaz Patt-Shamir on strategies for description of 
algorithms, including 
an intersection algorithm that might help) 

Intuition:
G is the concrete class graph used to instantiate a group of APPCs.
S1 is one of the strategies in the APPCs that defines traversals
of G-objects.
S2 is a refinement of S1 (defining a more restrictive traversal).
You can think of S2 being the result of combining S1 with
additional constraints of mapping an interface class graph
into a class graph.

The example below shows what your program should accomplish.
It acts like an informed filter that listens to certain events
and then sends out new events.


Example:
Class graph:
A = B C.
B = D.
C = E F.
D = G.
G = Z.
E = Z.
F = Z.

Object traversed: A-object (there is only one)

Strategy:
S1: A -> *
S2: A -> D D -> Z
S1			S2
before A		before A
before ->A,B		before ->A,D
before B
before ->B,D	
before D    		before D
before ->D,G		before ->D,Z
before G
before ->G,Z	
before Z    		before Z
after Z    		after Z
after ->G,Z
after G
after ->D,G		after ->D,Z	
after D			after D
after B
before C
...			...	
after ->A,B		after ->A,D
after A			after A

The adapter bean does not have to listen to all 
events sent by the traversal bean. This speads up the event handling.

Implement first for embedded strategies and add later a name map.

Plan for project:

1. Do basic event adaptation.
2. Add name map.
3. Implement algorithm for checking refinement of strategies.

   http://www.ccs.neu.edu/home/lorenz/Meetings/draft
4. Integrate with Bill's traversal bean (Bill does the S1 traversal)

-- Karl