如何将superclass复制到Ruby中继承的class

Question

我在复制这两个 class 时遇到问题：

module NapakalakiGame
  class Player

  def initialize(name, level)
    @name = name
    @level = level
    @treasures = Array.new
    @quests = Array.new
  end
...
end

我想在这里复制上面class的一个实例：

module NapakalakiGame
  class CultistPlayer < Player

  def initialize(player, cultist)
    super
    @my_cultist_card = cultist
  end
...
end

我需要将Player变成一个邪教徒，所以我需要复制他所有的属性。 CultistPlayer 的构造函数接收要变形的 Player 和一张邪教卡。

例如，如果我有一个叫约翰的玩家，他有 30 级、5 种宝物和 20 个已完成的任务，当他成为邪教徒时，我需要全部保留。

Answer 1

你不能那样做，因为你的 Player#new 方法不接受同类参数，也不接受玩家作为参数。

但是您可以更改子类中的 initalize 方法和 super 调用以使其工作：

更改player.rb：

attr_reader :name, :level, :treasures, :quests # if you don't have getter methods

def initialize(name, level, treasures = nil, quests = nil)
  @name      = name
  @level     = level
  @treasures = treasures || []
  @quests    = quests || []
end

和cultist_player.rb:

def initialize(player, cultist)
  super(player.name, player.level, player.treasures, player.quests)
  @my_cultist_card = cultist
end

Answer 2

我不确定 "transform" 是最好的架构方法。但是如果你真的需要它你可以尝试这样写：

class CultistPlayer < Player
 def initialize(player, cultist)
   copy_variables(player)
   @my_cultist_card = cultist
 end

 def copy_variables player
   player.instance_variables.each do |name|
     instance_variable_set(name, player.instance_variable_get(name))
   end
 end
end

#usage:
simple_player = Player.new('Ben', 10)
cultist = CultistPlayer.new(simple_player, 'some cultist card')

如何将superclass复制到Ruby中继承的class

How to copy the super class into the inherited class in Ruby

ruby

copy-constructor