[ruby-core:31967] [Ruby 1.9-Bug#3768] Constant Lookup doesn't work in a subclass of BasicObject

Issue #3768 has been updated by Thomas Sawyer.


I see the technical reason it occurs, but to accept that as proper behavior is going to hobble the usefulness of BasicObject.

First of all, it means one's ability to open a class and modify it will be conditional. One will have to check if it is a BasicObject upfront. That's easy to do if you're working with one class you already know, but consider how it effects doing some meta-programming where code is injected into any arbitrary class.

Worst still is that it makes importing code into a namespace very fragile. Consider the simplistic example of having some code in a script to eval into a module.

  module M
    eval(File.read('file.rb'))
  end

If file.rb contains:

  class R
  end

  class Q < BasicObject
    def r; R.new; end
  end

Then it will break whether we use R or ::R.

I feel the underlying issue here goes back to some other issues we've discussed some years ago about the top-level. Routing the toplevel to Object is not as flexible or robust as having a toplevel be an independent self-extended module in which constant resolution would terminate.
----------------------------------------
http://redmine.ruby-lang.org/issues/show/3768

----------------------------------------
http://redmine.ruby-lang.org