DSLの作り方

dsl.rb

# クラスメソッド Enalbe_foo                                                     
module Product
  def foo
    puts "OK2"
  end
end

class F
  include Product
end

class Object
  def acts_as_product
  #def self.acts_as_product
    include Product
  end
end
class G
  acts_as_product
end

class A < G
end
A.new.foo
#
module Foo
  def foo
    puts "OK foo"
  end
end
module Enalbe_foo
  module ClassMethods
    def enable_foo
      include Foo                                                               
    end
  end
  def self.included(base)
    base.extend(ClassMethods) # making class method
  end
end
# この手法のメリットは？
Object.instance_eval{include Enalbe_foo}

class H
  enable_foo # calling class method
end

class B < H
end
B.new.foo