Spell: Object Extension

object_extension.rb

# =======================
# Spell: Object Extension
# =======================

# Define Singleton Methods by mixing a module into an object’s singleton class.

obj = Object.new

module M
  def my_method
    'a singleton method'
  end
end

class << obj
  include M
end

obj.my_method # => "a singleton method"

# For more information: http://www.pragprog.com/titles/ppmetr/metaprogramming-ruby