From: Trans <transfire@...>
Date: 2005-10-12T15:16:52+09:00
Subject: Re: Default argument values for blocks


Eric Mahurin wrote:

> I agree.  In addition to eval within the block (or even a
> method that calls eval), you also have the issue that sometimes
> people (including me) have wanted to call eval with
> Proc#binding and want access to variables outside the block.  I
> think the majority of the time that is wanted is when the
> binding is from the caller, so those variables won't want to be
> GCed yet anyways.  One of the solutions I gave was to have all
> of the variables not directly referenced in the block be weak
> references in Proc#binding, so that GC wouldn't be prevented.
> GCing those unused variables would delete the weak references
> in Proc#binding.  I think this solution would maintain the best
> compatibility/flexibility and still solve the problem.

This still avoids a solution to closing scope for other uses. For
instance Class.new.

  A = Class.new {
    class B
      def x; 1; end
    end
  }

  class B
    def x; 2; 1
  end

  A::B
  (irb):19: warning: toplevel constant B referenced by A::B

There really needs to be a way to close that off.

T.