Patch Enumemator to play well with EM::Sunchrony

enumerator_patch.rb

class Enumerator
  class Error < Struct.new(:error)
  end
  def feed(v)
    @feed = v
  end
  class StopIteration < ::StopIteration
    attr :result
    def initialize(msg, result)
      super(msg)
      @result = result
    end
  end
  def next_values
    raise @stop if @stop
    if @peek
      peek, @peek = @peek, nil
      return peek
    end

    @fiber ||= Fiber.new do |parent|
      begin
        result = each {|*args|
          parent, feed = parent.transfer args
          feed
        }
        parent.transfer StopIteration.new("iteration reached an end", result)
      rescue Exception => e
        parent.transfer Error.new(e)
      end
    end
    feed, @feed = @feed, nil
    result = @fiber.transfer Fiber.current, feed
    case result
    when StopIteration
      @fiber.resume
      @fiber = nil
      @stop = result
      raise result 
    when Error
      @fiber = nil
      raise result.error
    end
    result
  end
  def _ary2sv(v, dup)
    case v
    when Array
      case v.size
      when 0 then nil
      when 1 then v[0]
      else
        dup ? v.dup : v
      end
    else
      v
    end
  end
  def next
    _ary2sv(next_values, false)
  end
  def peek
    @peek ||= next_values
    _ary2sv(@peek, true)
  end
end

use_patch.rb

require './enumerator_patch'
EM.synchrony do
  start = Time.now
  enum = Enumerator.new do |y|
    3.times do |i|
      EM::Synchrony.sleep 1
      y.yield i+100
    end
  end
  enum = enum.each_with_index
  puts "! #{enum.next.inspect}"
  puts "Time: #{Time.now - start}"
  EM.stop
end