From: Mauricio Fernandez <mfp@...>
Date: 2006-08-29T17:13:03+09:00
Subject: Re: Partial append_features?

On Tue, Aug 29, 2006 at 08:15:47AM +0900, Eero Saynatkari wrote:
> Robert Dober wrote:
> > unfortunately that approach undefines eralier defined methods in the
> > appendee, especially inherited ones :(
> > I guess that could be fixed but the code will become rather clumsy.
> 
> Heh, take another look:
> 
>      new_mod = Module.new     # Only this anonymous is affected
>      new_mod.module_eval do
>        include mod
>        methods_to_remove.each { |meth| undef_method meth }
>      end
> 
> A rather nice solution.

I think this is what he meant:

RUBY_VERSION                                       # => "1.8.5"
class X; def foo; "X#foo" end end
class Y < X; end
module M; def foo; "M#foo" end end
N = Module.new
N.module_eval do
  include M
  undef_method :foo
end

y = Y.new
y.foo                                              # => "X#foo"
class Y; include N end
y.foo                                              # => 
# ~> -:14: undefined method `foo' for #<Y:0xa7e04000> (NoMethodError)


IMO it's better to have the last call to #foo return X#foo.
You can do that by cloning the module then using remove_method on the copy.

-- 
Mauricio Fernandez  -   http://eigenclass.org   -  singular Ruby