dynamic_role_switching_spec.rb

$:.unshift(File.dirname(__FILE__), ".")
require 'rubygems'
require 'rspec'

module Butler

  def put_fork_on_the_left_of place
    place.unshift "fork"
    place 
  end

  def put_knife_on_the_right_of place
    place.push "knife"
    place 
  end
end

module LayTable

  def follow_instructions
   place = []
   put_fork_on_the_left_of place
   put_knife_on_the_right_of place 
  end
end

class MyActor
  #decide how we will make the actor know in which role they should perform the task
  def initialize role
    extend role
  end

  def perform task
    recall_how_to_do task 
    follow_instructions
  end

  private
  def recall_how_to_do something
    extend something
  end
end

describe "Something" do

  it "Something" do
    butler = MyActor.new Butler

    butler.perform(LayTable).should == ["fork","knife"]
  end
end

This approach removes the need for too much knowledge of what's being operated on.
If some value needs to be remembered for later use we should ask the actor to take_note_of key,value to save any information that will later need to be recalled... It can then be explicitly recalled by subsequent tasks