:stopdoc: REFACTOR: stolen from ruby_parser
/x/n.options
/x/e.options
/x/s.options
/x/u.options
{ EXTENDED => 'x', IGNORECASE => 'i', MULTILINE => 'm', ENC_NONE => 'n', ENC_EUC => 'e', ENC_SJIS => 's', ENC_UTF8 => 'u', }