From: Jim Weirich <jim@...>
Date: 2005-07-28T22:25:36+09:00
Subject: Re: What's so special about operators,      built-in classes and modules?


Austin Ziegler said:
> When a module is mixed into a class, its references to instance
> variables are bound to the instance of the class.
>
>   module Foo
>     def baz
>       @baz ||= 0
>       @baz += 1
>     end
>   end
>
>   class Bar
>     include Foo
>     def blat
>       @blat ||= 0
>       @blat += 1
>     end
>   end
>
>   moof = Bar.new
>   moof.instance_variables # => []
>   moof.blat; moof.instance_variables # => ["@blat"]
>   moof.baz; moof.instance_variables # => ["@blat", "@baz"]
>
> If we include classes, then we have to start caring about the origin
> of instance variables.

How would the above output be different if Bar were a class and we
inherited from Bar?

-- 
-- Jim Weirich     jim@weirichhouse.org    http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct,
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)