What is ruled out

Basically, what the law of demeter rules out is the kind of internal data coupling that we earlier noted as being very bad. Instead, access must be mediate by explicit parameters.

My purpose here is not to say that the Law of Demter is a hard and fast rule, but to illustrate the kind of technique one can use to control visibility, and by controlling visibility, control complexity.

[audio] [real] Text to accompany slide10, in Chapter 17 of An Introduction to Object-Oriented Programming