class REXML::Parsers::LightParser

def parse
  root = context = [ :document ]
  while true
    event = @parser.pull
    case event[0]
    when :end_document
      break
    when :start_element, :start_doctype
      new_node = event
      context << new_node
      new_node[1,0] = [context]
      context = new_node
    when :end_element, :end_doctype
      context = context[1]
    else
      new_node = event
      context << new_node
      new_node[1,0] = [context]
    end
  end
  root
end