SimplePie_XML_Declaration_Parser::parse PHP Method

    function parse()
    {
        while ($this->state && $this->state !== 'emit' && $this->has_data()) {
            $state = $this->state;
            $this->{$state}();
        }
        $this->data = '';
        if ($this->state === 'emit') {
            return true;
        } else {
            $this->version = '';
            $this->encoding = '';
            $this->standalone = '';
            return false;
        }
    }

 function parse(&$data, $encoding)
 {
     // Use UTF-8 if we get passed US-ASCII, as every US-ASCII character is a UTF-8 character
     if (strtoupper($encoding) == 'US-ASCII') {
         $this->encoding = 'UTF-8';
     } else {
         $this->encoding = $encoding;
     }
     // Strip BOM:
     // UTF-32 Big Endian BOM
     if (substr($data, 0, 4) === "��") {
         $data = substr($data, 4);
     } elseif (substr($data, 0, 4) === "��") {
         $data = substr($data, 4);
     } elseif (substr($data, 0, 2) === "��") {
         $data = substr($data, 2);
     } elseif (substr($data, 0, 2) === "��") {
         $data = substr($data, 2);
     } elseif (substr($data, 0, 3) === "") {
         $data = substr($data, 3);
     }
     if (substr($data, 0, 5) === '<?xml' && strspn(substr($data, 5, 1), "\t\n\r ") && ($pos = strpos($data, '?>')) !== false) {
         $declaration = new SimplePie_XML_Declaration_Parser(substr($data, 5, $pos - 5));
         if ($declaration->parse()) {
             $data = substr($data, $pos + 2);
             $data = '<?xml version="' . $declaration->version . '" encoding="' . $encoding . '" standalone="' . ($declaration->standalone ? 'yes' : 'no') . '"?>' . $data;
         } else {
             $this->error_string = 'SimplePie bug! Please report this!';
             return false;
         }
     }
     // Work around libxml bug
     $data = str_replace('&lt;', '&#60;', $data);
     $data = str_replace('&gt;', '&#62;', $data);
     $data = str_replace('&amp;', '&#38;', $data);
     $data = str_replace('&apos;', '&#39;', $data);
     $data = str_replace('&quot;', '&#34;', $data);
     $return = true;
     // Create the parser
     $xml = xml_parser_create_ns($this->encoding, $this->separator);
     xml_parser_set_option($xml, XML_OPTION_SKIP_WHITE, 1);
     xml_parser_set_option($xml, XML_OPTION_CASE_FOLDING, 0);
     xml_set_object($xml, $this);
     xml_set_character_data_handler($xml, 'cdata');
     xml_set_element_handler($xml, 'tag_open', 'tag_close');
     // Parse!
     if (!xml_parse($xml, $data, true)) {
         $this->error_code = xml_get_error_code($xml);
         $this->error_string = xml_error_string($this->error_code);
         $return = false;
     }
     $this->current_line = xml_get_current_line_number($xml);
     $this->current_column = xml_get_current_column_number($xml);
     $this->current_byte = xml_get_current_byte_index($xml);
     xml_parser_free($xml);
     return $return;
 }