From: ara.t.howard@...
Date: 2007-04-17T07:23:19+09:00
Subject: Re: "restoring" classes after changing stuff

On Tue, 17 Apr 2007, Marcelo Alvim wrote:

> Hi,
>
> Well, I'm new to Ruby (I've been working and playing with it for the
> last 6 months only), and
> I know there's probably another way in which this could work, but
> somehow I feel like the
> code below should work. Let's see what you guys think about it.
>
> The idea is making a copy of a class object, changing it and then
> restoring it back to what it was after playing with the new stuff I
> added. It should go somewhat like this:
>

you can't easily undo class changes.  better to not make them in the first
place.  this will work


harp:~ > cat a.rb
module ProxyClass
   def self.new parent
     Class.new(parent) do
       const_set :PARENT, parent
       instance_methods.each{|m| undef_method m unless m[%r/__/]}
       c = self and define_method(:class){ c }
       def method_missing m, *a, &b
         self.class::PARENT.instance_method(m).bind(self).call(*a, &b)
       end
     end
   end
end
class Class
   def proxy() ProxyClass.new(self) end
end

A = Array.proxy

class A
   def foo() :foo end
end

a = A[ 0, 1, 2 ]

p a.class
p a[0]
p a.first(2)
p a.foo



harp:~ > ruby a.rb
A
0
[0, 1]
:foo


regards.


-a
-- 
be kind whenever possible... it is always possible.
- the dalai lama