/span>
  <span class='kw'>while</span> <span class='id identifier rubyid_current'>current</span> <span class='op'>!=</span> <span class='kw'>nil</span>
    <span class='id identifier rubyid_next_current'>next_current</span> <span class='op'>=</span> <span class='id identifier rubyid_current'>current</span><span class='period'>.</span><span class='id identifier rubyid_next'>next</span>
    <span class='kw'>yield</span> <span class='id identifier rubyid_current'>current</span>
    <span class='id identifier r