From: ptkwt@... (Phil Tomson)
Date: 2006-02-15T11:23:27+09:00
Subject: extend quesion

The following doesn't quite do what I would expect:

module A
    def foo
       "A::foo" 
    end
end
module B
    def foo
       "B::foo" 
    end
end
class Demo
    def to_a
        self.extend(A)
    end
    def to_b
        self.extend(B)
    end
    def initialize
      self.extend(A)
    end
end


d = Demo.new
puts d.foo  #=> A::foo 
d.to_b
puts d.foo  #=> B::foo
d.to_a
puts d.foo  #=> B::foo (but I expected A::foo)


OK, I can kind of see why this happended; B's foo 'hide's A's foo method.  But 
I'm not sure why it didn't happen in the second 'puts' above (ie. why 
wouldn't it just keep printing A::foo every time?).  I think the answer is that 
A has already been mixed-in so it's not really mixed-in again (true?).


And how would I go about making this work so that it prints:

A::foo
B::foo
A::foo

?

Phil