如何在Ruby中创建用于对象的深层复制/克隆的运算符? [英] How to create an operator for deep copy/cloning of objects in Ruby?

问题描述

我想通过引入一个新的运算符(例如:=)来实现以下目标

I would like to achieve the following by introducing a new operator (e.g. :=)

a := b = {}
b[1] = 2
p a # => {}
p b # => {1=>2}

据我了解，我需要修改Object类，但是我不知道该怎么做才能得到我想要的东西.

As far as I understand, I need to modify the Object class, but I don't know what to do in order to get what I want.

require 'superators'
class Object
  superator ":=" operand # update, must be: superator ":=" do |operand|
    # self = Marshal.load(Marshal.dump(operand)) # ???
  end
end

您能帮我吗?

更新

好吧，超级管理员可能不会在这里帮助我，但我仍然想要这样的操作员.我(或您)如何为Ruby创建扩展，可以将其作为模块加载?

Ok, superators will probably not help me here, but I still want such operator. How can I (or you) create an extension for Ruby, which I could load as a module?

require 'deep_copy_operator'
a !?= b = {} # I would prefer ":=" but don't really care how it is spelled
b[1] = 2
p a # => {}
p b # => {1=>2}

推荐答案

首先，超级符号的语法为

First of all, the syntax for superators is

superator ":=" do |operand|
  #code
end

这是一个块，因为超级程序是一个元编程宏.

It's a block, because superator is a metaprogramming macro.

第二，您在Marshal上做了一些事情...但是有点魔术.只要您完全了解自己在做什么，就可以随意使用它.

Secondly, you have something going their with Marshal...but it's a bit of magic-ish. Feel free to use it as long as you understand exactly what it is you're doing.

第三，您在做的事情对超级操作器来说不太可行(我相信)，因为在功能中不能修改self. (如果其他人知道，请告诉我)

Thirdly, what you are doing isn't quite doable with a superator (I believe), because self cannot be modified during a function. (if someone knows otherwise, please let me know)

另外，在您的示例中，a必须首先存在并且已定义，然后才能在其中调用方法:=.

Also, in your example, a must first exist and be defined before being able to call the method := in it.

您最好的选择可能是:

class Object
  def deep_clone
    Marshal::load(Marshal.dump(self))
  end
end

生成对象的深层克隆.

a = (b = {}).deep_clone
b[1] = 2
p a # => {}
p b # => {1=>2}

这篇关于如何在Ruby中创建用于对象的深层复制/克隆的运算符?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！