Hi Boaz:

Edge-free strategies can indeed be very useful, especially
with the adaptive methods which Doug is implementing now.

You can define a strategy with 10 nodes and then do a

before * (@ some code @)

and now all 10 classes will have a method with the interface
of the adaptive method and identical bodies.

So edge-free strategies are useful to distribute common methods
to a bunch of classes.

Doug's new syntax already allows this.
AdaptiveMethodBody      = TraversalExpression VisitorExpression.
etc.
in:
vega::</home/dougo/demjava/src/demjava.cd

-- Karl

From boaz@ccs.neu.edu Wed Jul 30 09:46:23 1997
To: Karl Lieberherr <lieber@ccs.neu.edu>
cc: dougo@ccs.neu.edu
Subject: Re: special cases

Karl Lieberherr writes:
 > Regarding the first case, if we make zero copies of the class graph,
 > doesn't that result in an empty graph? But we would like to have one
 > node left?
 > 
You're right. But edge-free strategies do not make too much sense, do
they?
Boaz

===========================================
Hi Boaz:

do you agree with the following two special cases?
I think that the first is not handled by our paper. We should add it.

Doug, how does your implementation handle those two special cases?

-- Karl


Special case 1:
=============================

Strategy graph S:

A (no edges, only one node)
----------------
Class graph C:

A = B.
B = .

PathSet_S(C) = the single node path consisting of A.

This property is important so that we can say that a method
is a degenerate traversal: we visit only one object.

===================
Special case 2:
=============================


Strategy graph S:

from A to A (two different strategy graph nodes)
----------------
Class graph C:

A = .

PathSet_S(C) = the single node path consisting of A.