From: GOTO Kentaro <gotoken@...>
Date: 2002-07-17T16:10:28+09:00
Subject: Re: alias_method problem

At Wed, 17 Jul 2002 05:09:08 +0900,
Steve Tuckner wrote:

> I too have run in to this and implemented an ugly kludge to deal with it
> (instead of taking the time to figure it out).

I have another trick. 

  require "noreload"

  class Foo
    include NoReload

      alias_method :oldone, :newone
      def newone
         oldone
      end

    no_reload_upto_here!
  end

noreload uses a continuation but not tested enough. 

  % cat noreload.rb

  class ReloadError < StandardError
  end

  module NoReload
    def self.append_features(mod)
      super
      mod.class_eval do
        unless @no_reload_included_position
          @no_reload_included_position = caller[4]
        else
          if @no_reload_included_position == caller[4]
            @no_reload_upto_here or raise ReloadError,
              "`no_reload_upto_here!' wasn't called in previous definition",
              caller[3..-1]
            @no_reload_upto_here.call
          end
        end

        def mod.no_reload_upto_here!
          @no_reload_upto_here and raise ReloadError,
            "`no_reload_upto_here!' called twice", caller[0]
          callcc{|@no_reload_upto_here|}
        end
      end
    end
  end

Full version:
http://www.notwork.org/~gotoken/ruby/p/as-is/noreload.rb
http://www.notwork.org/~gotoken/ruby/p/as-is/noreload-test.rb