From: "ko1 (Koichi Sasada)" <redmine@...>
Date: 2013-02-22T09:10:21+09:00
Subject: [ruby-core:52654] [ruby-trunk - Feature #7748] Contextual send


Issue #7748 has been updated by ko1 (Koichi Sasada).

Assignee set to matz (Yukihiro Matsumoto)

I think matz tried it.
Matz: Could you give us your knowledge?

----------------------------------------
Feature #7748: Contextual send
https://bugs.ruby-lang.org/issues/7748#change-36740

Author: trans (Thomas Sawyer)
Status: Open
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


=begin
If I write a method that uses #send vs. #public_send, I am making an assumption about how that method is invoked. For example, take the simplest form of such a method:

  class String
    def send_out(op, *a, &b)
      send(op, *a, &b)
    end
  end

This code has a bug in it, in the sense that it can be used to call private string methods. The solution is to use #public_send. In most cases that will be fine. But if anyone tries to reuse the method while extending String themselves, e.g.

  class String
    def send_out(op, *a, &b)
      public_send(op, *a, &b)
    end

    def some_public_method
      send_out(:some_private_method)
    end

    private
    def some_private_method
    end
  end

Then it will be a problem b/c it cannot be used on a private supporting method.

So it seems like there should be something like a ((*contextual send*)) which invokes a send with the same visibility as the parent method is invoked. e.g.

  class String
    def send_out(op, *a, &b)
      contextual_send(op, *a, &b)
    end
  end

And then all cases will work as expected.
=end


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