On Friday, October 11, 2002, at 04:53  PM, Alex Peake wrote:

> It is a way to add a (reusable) behavior to several classes.
>
> A Mixin is a separate class that through MI adds some functionality. 
> It is the way it is designed
> and used that causes it to be called a Mixin rather than a "super" or 
> "parent" class.

Ruby does quite a good job of this with it's module system. It does 
mixins with single inheritance, though for a language as dynamic as 
Ruby, the distinction is a pretty fine point.

The book Programming Ruby has a pretty good description,, available on 
the web here:

http://www.rubycentral.com/book/tut_modules.html


Cheers,

Colin

Colin Putney
Whistler.com