gross_methods.rb

# The following shows how to pass around methods in Ruby

# Unbound methods in Ruby suck, they can only be re-bound to objects that are
# a #kind_of? the original
class ReallyUnboundMethod
  def initialize(name, body)
    @name, @body = name, body
  end

  def bind(obj)
    method_body = @body
    evaluator = Proc.new do
      obj.instance_eval &method_body
    end
    metaclass = class << obj; self; end
    metaclass.send(:define_method, @name, evaluator)
  end
end

class Method
  def really_unbind
    ReallyUnboundMethod.new(name, to_proc)
  end
end

class You
  def pronoun
    "You"
  end

  def tomato(blah = nil)
    p blah
    pronoun + " say tomato"
  end
end

class Me
  def pronoun
    "I"
  end
end

you = You.new
me = Me.new

p you.tomato
you.method(:tomato).really_unbind.bind(me)
p me.tomato