gistfile1.scm

(define (make-string q)
  (let* ([%quote ($char q)]
         [%escape ($char #\\)]
         [%hex4 ($fmap (^s (string->number (list->string s) 16))
                       ($many hexdigit 4 4))]
         [%special-char
          ($do %escape
               ($or ($char q)
                    ($char #\\)
                    ($char #\/)
                    ($do [($char #\b)] ($return #\x08))
                    ($do [($char #\f)] ($return #\page))
                    ($do [($char #\n)] ($return #\newline))
                    ($do [($char #\r)] ($return #\return))
                    ($do [($char #\t)] ($return #\tab))
                    ($do [($char #\u)] (c %hex4) ($return (ucs->char c)))))]
         [%unescaped ($none-of (char-set q) )]
         [%body-char ($or %special-char %unescaped)]
         [%string-body ($->rope ($many %body-char))])
    ($between %quote %string-body %quote)))

; 文字列はシングルクオートとダブルクオート
(define %string ($or (make-string #\') (make-string #\") ) )