behaviours

[Jay Nelson]

 > It seems to me that the distinction you're trying to make is between
 > interfaces (i.e., behaviours - they *are* the same) and what is usually
 > known as mixin classes (a form of multiple inheritance of
 > implementations).

I'd say the modern day morph of mixins is now called Aspect
Oriented Programming:

http://citeseer.nj.nec.com/kiczales97aspectoriented.html

It takes a slightly different twist in that it is a "post-programming"
method of fixing up classes consistently to add in a functionality
shared by all participating classes.

I've wanted to combine AOP, mixins and erlang's functional style
to produce ESOO (erlang-style object-oriented) that is a purely
function combination of callback plug-ins, but of course it is pushed
way down on my to-do list.  Sounds a lot like what this behaviours
discussion is about -- sharing interfaces, callbacks and plug-ins.

jay