从 Ruby 中的方法中检索 Method 实例 [英] Retrieving the Method instance from within a method in Ruby

问题描述

这是如何确定定义方法的类的后续问题?(希望你不介意相似)

This is a follow-up question to How to determine the class a method was defined in? (hope you don't mind the similarity)

给定一个类层次结构，一个方法可以检索它自己的Method实例吗?

Given a class hierarchy, can a method retrieve its own Method instance?

class A
  def foo
    puts "A#foo: `I am #{method(__method__)}'"
  end
end

class B < A
  def foo
    puts "B#foo: `I am #{method(__method__)}'"
    super
  end
end

A.new.foo
# A#foo: `I am #<Method: A#foo>'

B.new.foo
# B#foo: `I am #<Method: B#foo>'
# A#foo: `I am #<Method: B#foo>' # <- A#foo retrieves B#foo

这样 B.new.foo 代替打印

# B#foo: `I am #<Method: B#foo>'
# A#foo: `I am #<Method: A#foo>' # <- this is what I want

在上一个问题中，Jörg W Mittag 怀疑检索方法在其中定义的类可能会违反面向对象范式.这也适用于这里吗?

In the previous question, Jörg W Mittag suspected that retrieving the class a method was defined in might violate object-oriented paradigms. Does this apply here, too?

方法不应该知道自己"吗?

Shouldn't a method "know itself"?

推荐答案

我发现了一个 方法正是这样做的.

I found a method that exactly does that.

class A
  def foo
    puts "A#foo: `I am #{method(__method__).super_method || method(__method__)}'"
  end
end

我真的很佩服 Matz 和 Ruby 核心开发人员.这种方法的存在，意味着他们心里已经有了这样的情况，并且已经想好要怎么办了.

I really admire Matz and the Ruby core developers. The existence of such method means that they had in mind such situation, and had thought about what to do with it.

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