Passing classes vs objects

gistfile1.rb

# Passing classes

class Item
  def apply_coupon(coupon_class)
    coupon_class.new(self).apply
  end
end

class Coupon
  attr_reader :target

  def initialize(target)
    @target = target
  end
end

class SomeCoupon < Coupon
  def apply
    target.price -= 10_00
  end
end


# Passing objects

class Item
  def apply_coupon(coupon)
    coupon.apply_to(self)
  end
end

class Coupon
  attr_reader :target

  def apply_to(target)
    @target = target
    apply
  end
end

class SomeCoupon < Coupon
  def apply
    target.price -= 10_00
  end
end