From: ts <decoux@...>
Date: 2002-12-15T20:27:35+09:00
Subject: Re: un-extending objects

>>>>> "d" == dblack  <dblack@candle.superlink.net> writes:

d>   # Object#stretch(aModule) -- extend only for duration of block
d>   class Object
d>     def stretch(mod)
d>       c = class << self; self; end
d>       before = methods
d>       extend(mod)
d>       yield
d>       (methods - before).each { |m| c.class_eval {undef_method(m)} }
d>     end
d>   end

 Nice, very nice :-)))

pigeon% cat b.rb
#!/usr/bin/ruby
class Object
   def stretch(mod)
      c = class << self; self; end
      before = methods
      extend(mod)
      yield
      (methods - before).each { |m| c.class_eval {undef_method(m)} }
   end
end

class A
   def a
      puts "a"
   end
end

module M
   def a
      puts "b"
   end
end

a = A.new
a.a
a.stretch(M) { a.a }
a.a
pigeon%
 
pigeon% b.rb
a
b
b
pigeon% 


Guy Decoux