为什么 Ruby 2.0 改进后“发送"会失败? [英] Why does `send` fail with Ruby 2.0 refinement?

问题描述

为什么这不起作用?

module StringRefinement
  refine String do
    def bar
      length
    end
  end
end

using StringRefinement
"abcdefghijklmnopqrstuvwxyz".send(:bar)
#NoMethodError: undefined method 'bar' for "abcdefghijklmnopqrstuvwxyz":String

有人可以解释为什么 send 在这里不起作用吗?有没有办法动态调用细化中定义的方法?我似乎找不到关于 Ruby 2.0 中细化如何工作的完整解释.

Can someone explain why send doesn't work here? And is there a way to dynamically call methods defined in a refinement? I can't seem to find a good, full explanation of how refinements work in Ruby 2.0.

推荐答案

因为规范 是这样说的:

任何间接方法访问，例如 Kernel#send、Kernel#method 和 Kernel#respond_to? 都不应支持调用者中的改进方法查找期间的上下文.

Indirect method accesses

Any indirect method access such as Kernel#send, Kernel#method, and Kernel#respond_to? shall not honor refinements in the caller context during method lookup.

这篇关于为什么 Ruby 2.0 改进后“发送"会失败?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！