middle ware pattern

middle.rb

module Middle
  module Base
    def self.included(base)
      base.extend self
    end

    def returning value=nil
      throw :done, value
    end
  end

  def use m, *args
    middlewares << [m, args]
  end

  def middlewares
    @middlewares ||= [].tap { |this|
      def this.run(input=nil)
        catch(:done) { inject(input) { |r, m| m[0].call(r, *m[1]) }}
      end
    }
  end
end

sample.rb

include Middle

class M1
  def self.call *args
    puts *args
    "From M1"
  end
end

class M2
  include Middle::Base

  def self.call *args
    puts *args
    returning "return from M2"
  end
end

class M3
  def self.call *args
    "M3 untouched"
  end
end


use M1
use M2
use M3

result = middlewares.run "hello wolrd"
puts result

# => hello world
# => From M1
# => return from M2