M

terrible.rb

#!/usr/bin/ruby
# -*- coding: utf-8 -*-


class Function
  attr_reader :block

  def initialize &block
    @block = block
  end

  def -@
    self
  end

  def < other
    Function.new { |x| block[other.block[x]] }
  end
end


puts (Function.new { |x| x + 1 } <- Function.new { |x| x * 3 }).block[2]
# => 7