dice

dice.rb

class Integer
  DICE_REGEX = /\Ad(\d+)\z/.freeze

  def method_missing(method_name, *args, &block)
    sides = method_name.to_s.match(DICE_REGEX)

    super unless sides

    times.map { rand(sides[1].to_i) + 1 }.inject(:+)
  end

  def respond_to_missing?(method_name, include_private = false)
    method_name.to_s.match(DICE_REGEX) || super
  end
end

puts 1.d10
puts 2.d20
puts 3.d6
puts 4.respond_to?(:d12)
puts 4.respond_to?(:dsgfhf)