Hi Mitch:

I was thinking about a marriage of traversal automata and strategies.
The nodes in a strategy graph can be viewed as states.
Consider the strategy with class map:

{-> q0:A q1:C
 -> q1:C q2:D}

The class graph is:
A = B.
B = [C] D.
C = B.
D = .

At class B we have the generated state transitions:

((B q0) (TRAVERSE c q0)
 (B q1) (TRAVERSE c q1) (TRAVERSE d q1))

Now the "marriage" would consist of allowing the strategy
specifier to take complete control at certain classes.

For example, we can refine the above strategy with

((A q0) (TRAVERSE b q0) (TRAVERSE b q3)
 (B extend with 
    (B q3) () // nothing
)

This means that at A we traverse the b edge twice and at
B we go further only if in states q0 or q1.

Regarding visitor actions, I like a specification of the form:

before
  B         during {set of states} v1
  -> B,c,C  during {set of states} v2

same for after. Maybe we want a substrategy in addition to
a set of states.

It is important that we view the extended strategies to be defined
in terms of class-valued variables.

-- Karl