从复杂方法链中获取父实例化对象？

Question

原谅我设计的例子，如果我有.

class Condiment
  def ketchup(quantity)
    puts "adding #{quantity} of ketchup!"
  end
end

class OverpricedStadiumSnack
  def add
    Condiment.new
  end
end

hotdog = OverpricedStadiumSnack.new

..。在调用hotdog时，是否可以从Condiment#ketchup内部访问实例化的hotdog.add.ketchup('tons!')对象？

到目前为止，我找到的唯一解决方案是显式传递hotdog，如下所示：

class Condiment
  def ketchup(quantity, snack)
    puts "adding #{quantity} of ketchup to your #{snack.type}!"
  end
end

class OverpricedStadiumSnack
  attr_accessor :type

  def add
    Condiment.new
  end
end

hotdog = OverpricedStadiumSnack.new
hotdog.type = 'hotdog'

# call with
hotdog.add.ketchup('tons!', hotdog)

..。但是，我希望能够在不显式传递hotdog的情况下做到这一点。

Answer 1

可能是：

class Condiment
  def initialize(snack)
    @snack = snack
  end

  def ketchup(quantity)
    puts "adding #{quantity} of ketchup! to your #{@snack.type}"
  end
end

class OverpricedStadiumSnack
  attr_accessor :type

  def add
    Condiment.new(self)
  end
end

hotdog = OverpricedStadiumSnack.new
hotdog.type = 'hotdog'
hotdog.add.ketchup(1)