From: matz@... (Yukihiro Matsumoto)
Date: 2001-06-08T15:05:12+09:00
Subject: [ruby-talk:16322] Re: require and include confusion

Hi,

Sorry for being late.  I missed this one somehow.

In message "[ruby-talk:16074] Re: require and include confusion"
    on 01/05/31, Mathieu Bouchard <matju@sympatico.ca> writes:

|But I have just found a case where it actually matters. Here it is:
|
|module A; end
|module B; include A; end
|module C; include A; end
|[A,B,C].each{|k| k.module_eval "def foo; '#{k}' + super; end" }
|module Kernel; def foo; "" end end
|x = Object.new; x.extend C; p x.foo
|include B; p x.foo
|x = Object.new; x.extend C; p x.foo
|
|This prints:
|	"CA"
|	"CABA"   # A is seen twice in old x
|	"CBA"    # A is seen once  in new x

Well, module duplication check is done when "include" is done.  So
that if insertion to upper level (Object this case) is done AFTER any
insertion, it would be remain doubled.  I don't think I can rescue
this case.

							matz.