_getLines example

            if ($match[3] == 'd') {
                $to_line_no--;
            }

            if ($from_line_no < $match[1] || $to_line_no < $match[4]) {
                // copied lines                 assert($match[1] - $from_line_no == $match[4] - $to_line_no);
                array_push($edits,
                    new Text_Diff_Op_copy(
                        $this->_getLines($from_lines, $from_line_no, $match[1] - 1),
                        $this->_getLines($to_lines, $to_line_no, $match[4] - 1)));
            }

            switch ($match[3]) {
            case 'd':
                // deleted lines                 array_push($edits,
                    new Text_Diff_Op_delete(
                        $this->_getLines($from_lines, $from_line_no, $match[2])));
                $to_line_no++;
                break;