From: Brian Marick <marick@...>
Date: 2001-10-07T09:20:10+09:00
Subject: [ruby-talk:22180] Redefining class that does not inherit with class that does

Suppose that you run this code:

class Sub
   def foo
     "SUB foo!"
   end
end

class Super
   def foo
     "SUPER foo!"
   end
end

# note: redefining Sub
class Sub < Super
   def bar
     "bar!"
   end
end

You get a "warning: already initialized constant Sub", which seems fine. 
Question: when you do "Sub.new.foo", which foo do you get? I expected 
Super's - that the new version of Sub would wipe out the old. I was 
surprised that you got neither. foo is not a method Sub responds to. (bar is.)

I'm not sure my expected behavior is correct. The second "class Sub" might 
instead add a method "bar" to the exiting "foo" and link Super into the 
inheritance chain of Sub. But eliminating "foo" seems odd.

Ruby 1.6.3

Is there a way to destroy the old definition of Sub before the second 
"class Sub"? I'm writing text that explains inheritance, and it's awkward 
to say "if you're following along with IRB, be sure to exit your session now."

--
Brian Marick, marick@testing.com
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