private function _parseQuotedAttrString(int &$offset): string
    {
        $idx = $offset + 1;
        $val = "";
        while ($idx < $this->_len) {
            $c = $this->_dn[$idx];
            if ("\\" == $c) { // pair
                ++$idx;
                $val .= $this->_parsePairAfterSlash($idx);
                continue;
            } else if ('"' == $c) {
                ++$idx;
                break;
            }
            $val .= $c;
            ++$idx;
        }
        $offset = $idx;
        return $val;
    }
private function _parseQuotedAttrString(int &$offset): string
    {
        $idx = $offset + 1;
        $val = "";
        while ($idx < $this->_len) {
            $c = $this->_dn[$idx];
            if ("\\" == $c) { // pair
                ++$idx;
                $val .= $this->_parsePairAfterSlash($idx);
                continue;
            } else if ('"' == $c) {
                ++$idx;
                break;
            }
            $val .= $c;
            ++$idx;
        }
        $offset = $idx;
        return $val;
    }
private function _parseQuotedAttrString ( int & $ offset ) : string { $ idx = $ offset + 1 ; $ val = "" ; while ( $ idx < $ this -> _len ) { $ c = $ this -> _dn [ $ idx ] ; if ( "\\" == $ c ) { // pair ++ $ idx ; $ val .= $ this -> _parsePairAfterSlash ( $ idx ) ; continue ; } else if ( '"' == $ c ) { ++ $ idx ; break ; } $ val .= $ c ; ++ $ idx ; } $ offset = $ idx ; return $ val ; }
Parse quoted 'attributeValue' string.

@param int $offset Offset to starting quote
@throws \UnexpectedValueException
@return string
Parse quoted attributeValue string .