SimplePie_Misc::space_seperated_tokens PHP Method

    function space_seperated_tokens($string)
    {
        $space_characters = " \t\n\v\f\r";
        $string_length = strlen($string);
        $position = strspn($string, $space_characters);
        $tokens = array();
        while ($position < $string_length) {
            $len = strcspn($string, $space_characters, $position);
            $tokens[] = substr($string, $position, $len);
            $position += $len;
            $position += strspn($string, $space_characters, $position);
        }
        return $tokens;
    }

 function result()
 {
     if ($this->data['file']->url != 'http://diveintomark.org/tests/client/autodiscovery/') {
         parent::result();
     }
     static $done = array();
     $links = SimplePie_Misc::get_element('link', $this->data['file']->body);
     foreach ($links as $link) {
         if (!empty($link['attribs']['href']['data']) && !empty($link['attribs']['rel']['data'])) {
             $rel = array_unique(SimplePie_Misc::space_seperated_tokens(strtolower($link['attribs']['rel']['data'])));
             $href = SimplePie_Misc::absolutize_url(trim($link['attribs']['href']['data']), $this->data['file']->url);
             if (!in_array($href, $done) && in_array('next', $rel)) {
                 $done[] = $this->data['url'] = $href;
                 break;
             }
         }
     }
     if ($this->data['url']) {
         $this->run();
     }
 }