Composed in Ruby

composed.rb

module Kernel
  def composed(actions)
    lambda do |*args, &block|
      actions.reverse.reduce(*args) do |result, next_op|
        result = next_op.call(result, &block)
      end
    end
  end
end

class Class
  def composed_method(name, actions, *options)
    if options.include?(:class_method)
      define_singleton_method name, &composed(actions)
    else
      define_method name, &composed(actions)
    end
  end
end

class Ops
  def self.plus_one(x)
    x + 1
  end       
  def self.times_two(x)
    x * 2
  end       
  def self.sq(x)
    x * x
  end
  composed_method :all_of_the_above, [:plus_one, :times_two, :sq].map { |x| method(x) }, :class_method
end


methods = [:plus_one, :times_two, :sq]
methods.map! { |x| Ops.method(x) }
methods # => [#<Method: Ops.plus_one>, #<Method: Ops.times_two>, #<Method: Ops.sq>]
composed(methods).call(1) # => 3
composed(methods).call(2) # => 9
composed(methods).call(3) # => 19

plus_one = -> x { x + 1}
times_two = -> x { x * 2}
sq = -> x { x * x}

methods = [plus_one, times_two, sq] # => [#<Proc:0x007fd58c046fa0@-:42 (lambda)>, #<Proc:0x007fd58c046f78@-:43 (lambda)>, #<Proc:0x007fd58c046f50@-:44 (lambda)>]

composed(methods).call(1) # => 3
composed(methods).call(2) # => 9
composed(methods).call(3) # => 19


Ops.all_of_the_above(1) # => 3
Ops.all_of_the_above(2) # => 9
Ops.all_of_the_above(3) # => 19