Stuart:

here is an answer to your question to Alexey.

-- Karl

Let's assume you have a class

A = <b> B.

and from A exactly one B is reachable.

In Demeter/Java, instead of using the generated get_b() you can write
your own adaptive version:

// an adaptive method where visitor is inlined and strategy
// is explicit.

A{
  B my_get_b() to B {
    before B (@ return_val = host; @)
  }
}

Advantages of my_get_b():

it will work correctly, without change,
if the B gets more deeply nested inside the A.

Disadvantages of my_get_b():
You have to maintain the invariant, as the 
class graph evolves, that from A exactly one B is reachable.
Or alternatively, you have to update the strategy used by 
my_get_b(). Maintaining the invariant or changing the strategy
is easier than maintaining the access code yourself.

When should you use my_get_b() instead of get_b()?
If you expect the A class to evolve so that the B-class gets 
deeper nested in the A-class. The decision is up to you.

See (LoD-PP) in:
ftp://ftp.ccs.neu.edu/pub/people/lieber/faq/Demeter-FAQ

-- Karl Lieberherr