在Ruby中使用新的运算符对自动生成哈希进行多重初始化 [英] Multiple initialization of auto-vivifying hashes using a new operator in Ruby

问题描述

我想初始化几个自动生成哈希。到目前为止，我对 AutoHash 对象有一个额外的方法：

  class AutoHash<哈希
 ... 
 def few（n = 0）
 Array.new（n）{AutoHash.new} 
 end 
  
 
 
 
允许我做以下操作
  a ，b，c = AutoHash.new.few 3 
  
然而，我觉得可以做以下可能通过定义一个新的操作符：=  
  a：= b ：= c = AutoHash.new 
  
您能帮我实施吗？
 
 
 
 
 
 
我必须使用 superators ？
  require'superators'
 
 class AutoHash<哈希
 ... 
 superator：=do | operand | 
如果operand.kind_of？ Hash 
 ... 
 else 
 ... 
 end 
 end 
  
 
 
 
 
 
 
 更新：现在我发现运营商需要在课堂外定义。是否有可能定义这样的对象克隆操作符？
 
 
 
 
 
 
  Update2 更明确的方法定义少数，感谢Joshua 
 
 
 
 
 
 
 参考资料 
 
 
  http://www.linux-mag.com/cache/7432/1.html  
 
 
  Ruby是否支持像PHP这样的var引用？ 
 
 
  http://ruby.about.com/od/advancedruby/a/deepcopy.htm  
 
 
 
 
解决方案
在哪里要求 a：= b：= c： = AutoHash.new.few 3 我想（不知道我理解你的愿望），你真的想要 a，b，c = Autohash.new.few 3  
 
 
 
为什么很少有var当你只使用第一个参数时，这些参数是否可信？ 
 
 
 
我也发现你创建的返回值会令人困惑，也许试试吧。 c $ c> def few（n = 0）
 Array.new（n）{AutoHash.new} 
 end 
  

---

除此之外，似乎少数应该是一个类方法。 a，b，c = AutoHash.few 3 如果您在课堂上定义了很少的话，这将起作用：

<$ p $ （n = 0）
Array.new（n）{AutoHash.new}
结束

---

如果 a，b，c = AutoHash.few 3 不是你正在寻找的东西，而你真的想要实现你自己的操作符，然后检查 Hacking parse.y ，这是在RubyConf上给出的一个讨论您可以在观看演示文稿http://rubyconf2009.confreaks.com/19-nov-2009-17-15-hacking-parsey-tatsuhiro-ujihisa.html ，你可以在 http://www.slideshare.net/ujihisa/hacking-parsey-rubyconf-2009

I would like to initialize several auto-vivifying hashes by one-line expression. So far I came to an extra method for the AutoHash object:

class AutoHash < Hash
  ...
  def few(n=0)
    Array.new(n) { AutoHash.new }
  end

which allows me to do the following

a, b, c = AutoHash.new.few 3

However, I feel that one can make the following sentence possible by defining a new operator :=

a := b := c = AutoHash.new

Could you help me to implement this?

---

Do I have to use superators?

require 'superators'

class AutoHash < Hash
  ...
  superator ":=" do |operand|
    if operand.kind_of? Hash
      ...
    else
      ...
    end
  end

---

Update: Now I see that the operator needs to be defined outside the class. Is it possible to define such object clone operator?

---

Update2 More clear definition of method few, thanks to Joshua

---

References

1. http://www.linux-mag.com/cache/7432/1.html
2. Does Ruby support var references like PHP?
3. http://ruby.about.com/od/advancedruby/a/deepcopy.htm

解决方案

Where you ask for a := b := c := AutoHash.new.few 3 I think (not sure I understand your desire) that you really want a,b,c=Autohash.new.few 3

---

Why does few take variable args, when you only ever use the first?

I also find your creation of the return value to be confusing, maybe try

def few(n=0) 
  Array.new(n) { AutoHash.new } 
end 

---

Beyond that, it seems like few should be a class method. a,b,c=AutoHash.few 3 which will work if you defined few on the class:

def AutoHash.few(n=0)
  Array.new(n) { AutoHash.new }
end

---

If a,b,c=AutoHash.few 3 isn't what you're looking for, and you really want to implement your own operator, then check out Hacking parse.y, which was a talk given at RubyConf 2009. You can watch the presentation at http://rubyconf2009.confreaks.com/19-nov-2009-17-15-hacking-parsey-tatsuhiro-ujihisa.html and you can see the slides at http://www.slideshare.net/ujihisa/hacking-parsey-rubyconf-2009

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