ruby - Ruby 的方法查找路径

Question

我正在阅读“Well Grounded Rubyist”一书，我对方法查找路径有疑问:

module M
  def report
    puts "'report' method in module M"
  end
end

module N
  def report
    puts "'report' method in module N"
  end
end

class C
  include M
  include N
  def report
    puts "'report' method in class C"
    puts "About to call super..."
    super
    puts "Back from super..."
  end
end

obj = C.new
obj.report

根据我的理解，obj.report 会输出:

'report' method in class C
About to call super...
'report' method in module N
Back from super...

但是，我很好奇是否可以通过绕过 N 的报告，从类 C 中调用 M 的报告方法。我知道如果我在模块 N 中添加“super”，它会调用 N 的报告，然后调用 M 的报告在放置“从 super ...返回”之前，但是有没有办法直接从 C 执行此操作？

Answer 1

你可以使用祖先反射:

class C
  def report
    my_ancestors = self.class.ancestors
    puts "my ancestors are: #{my_ancestors}"
    method = my_ancestors[2].instance_method(:report)
    method.bind(self).call
  end
end

C.new.report
=> my ancestors are: [C, N, M, Object, PP::ObjectMixin, Kernel, BasicObject]
=> 'report' method in module M