在运行时将实例方法设为私有 [英] Make instance methods private in runtime

问题描述

在另一个对象中注册该对象后，我需要将一些实例方法设为私有。

I need to make some instance methods private after registering that object in another object.

我不想冻结该对象，因为该对象必须保持可编辑状态，并且功能较少。而且我不想取消定义方法，因为它们在内部使用。

I don't want to freeze the object because it must remain editable, only with less functionality. And I don't want to undef the methods since they are used internally.

我需要的是这样的东西：

What I need is something like:

class MyClass

  def my_method
    puts "Hello"
  end

end

a = MyClass.new
b = MyClass.new

a.my_method                            #=> "Hello"
a.private_instance_method(:my_method)
a.my_method                            #=> NoMethodError
b.my_method                            #=> "Hello"

有什么想法吗？

推荐答案

每个类 是什么是公开的，什么是私有的。但是每个对象都可以有自己的类：

What's public and what's private is per class. But each object can have its own class:

class Foo

  private

  def private_except_to_bar
    puts "foo"
  end

end

class Bar

  def initialize(foo)
    @foo = foo.dup
    class << @foo
      public :private_except_to_bar
    end
    @foo.private_except_to_bar
  end

end

foo = Foo.new
Bar.new(foo)    # => "foo"

foo.private_except_to_bar
# => private method `private_except_to_bar' called for #<Foo:0xb7b7e550> (NoMethodError)

但是。考虑以下替代方案：

But yuck. Consider these alternatives:

• 只需公开该方法即可。


• 探索替代设计。

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