Does anyone know what Alan means by "assignments are a metalevel change from functions, and therefore should not
be dealt with at the same level"? In what way are assignments a metalevel change from functions?
I believe he means that variable and their assignments are at a lower level. Objects interfaces should be defined in terms of the messages they can send and receive. No exposed variables: Variables should always be private/protected and are just used by the objects to maintain their internal state.