From: shugo@...
Date: 2015-12-10T07:07:22+00:00
Subject: [ruby-core:72025] [Ruby trunk - Bug #11779] Module#using does not make sense as a method

Issue #11779 has been updated by Shugo Maeda.


bug hit wrote:
> Shugo Maeda wrote:
> > ...
> > Because refinement activation should be as static as possible.
> > ...
> 
> ruby is too dynamic a language to have a clear distinction between what you're calling "static" and "dynamic"  You are labeling class bodies as "static" and methods "dynamic" but a class body is executable ruby and can be invoked by methods, so the current restriction on module_eval can be overcome with relative ease:

Methods are expected to be invoked more than once, so there's a significant difference from class bodies.
That's why static features like constant assignments are prohibited in method definitions.


----------------------------------------
Bug #11779: Module#using does not make sense as a method
https://bugs.ruby-lang.org/issues/11779#change-55437

* Author: bug hit
* Status: Feedback
* Priority: Normal
* Assignee: 
* ruby -v: 2.2.3
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
1. it can't be called from another method
2. the receiver must be self
3. since refinements are lexically scoped the self receiver must match the currently open class

#3 is particularly curious

```ruby
module Refinement
  refine String do
    def refined?
      true
    end
  end
end

module Foo
  def self.refined?
    ''.refined? rescue false
  end
end


module Bar
  def self.refined?
    ''.refined? rescue false
  end
  Foo.module_eval do
    using Refinement

  end
end

p Foo.refined? #false
```

The module_eval `#using` call does not raise (it's not from a method and the receiver is self), but evidently because currently open class does not match self, it does not do anything. So it should at least raise.

So `#using`, though a method, does not function as a method, which is misleading.



-- 
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