> I would look at the pickaxe book's chapter on reflection
> (http://www.rubycentral.com/book/ospace.html), which covers a lot of
> topics you'll probably find relevant and interesting, including
> runtime callbacks, examining ObjectSpace, and several others.

Hal Fulton also does a marvelous job of describing reflection and 
run-time extension in chapter 5 "OOP and Dynamicity in Ruby" of his 
"The Ruby Way" book. It's longer and a bit more advanced. I learned a 
ton from it.
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