From: alxtskrnk@... Date: 2015-12-10T07:01:58+00:00 Subject: [ruby-core:72024] [Ruby trunk - Bug #11779] Module#using does not make sense as a method Issue #11779 has been updated by bug hit. 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: ```ruby module Refinement refine String do def refined? true end end end module Foo end module Bar def self.mod_eval_with_refine(mod) singleton_class.instance_variable_set :@mod, mod class << self @mod.module_eval do using Refinement p((''.refined? rescue false)) end end end end Bar.mod_eval_with_refine(Foo) ``` ---------------------------------------- Bug #11779: Module#using does not make sense as a method https://bugs.ruby-lang.org/issues/11779#change-55436 * 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. -- https://bugs.ruby-lang.org/