class Reline::KillRing

def append(string, before_p = false)
  case @state
  when State::FRESH, State::YANK
    @ring << RingPoint.new(+string)
    @state = State::CONTINUED
  when State::CONTINUED, State::PROCESSED
    if before_p
      @ring.head.str.prepend(string)
    else
      @ring.head.str.concat(string)
    end
    @state = State::CONTINUED
  end
end