string->json和json->string不配套的workthrough

[xaengceilbiths]

这个库就是ovenpasta本人写的。
其中string->json和json->string并不配套，我勉强改动使得输出的json文件可以被其他软件读（其缩进有严重问题）。我的做法是用json1->json2转成json->string识别的格式，json->string对boolean做了识别。建议r7rs用(rebottled json)，r6rs要想想办法。
(rebottled json)的r7rs版本是 https://github.com/chaw/r7rs-libs/blob/master/rebottled/json.sld
(rebottled json)本身是 http://wiki.call-cc.org/eggref/5/json

[xaengceilbiths]

(define (json1->json2 json)
  (cond [(list? json)
         (cons '@ (map cons
                    (map car json)
                    (map json1->json2 (map cdr json))))]
        [(vector? json)
         (map json1->json2 (vector->list json))]
        [(boolean? json) json]
        [(null? json) json]
        [(number? json) json]
        [(string? json) json]
        [(bytevector? json) json]
        [(symbol? json) json]))
(define (json->string json)
  (define special '((#\backspace . #\b) (#\newline . #\n) (#\alarm . #\a) 
		    (#\return . #\r) (#\tab #\t) (#\\ . #\\) (#\" . #\")))
  (cond [(and (pair? json)  (eq? (car json) '@))
	 (string-append 
	  "{\n"
	  (string-intersperse
	   (map (lambda (pair)
		  (let ([k (car pair)]
			[v (cdr pair)])
		    (string-append "  " (json->string k)
				   " : " (json->string v))))
	     (cdr json))
	   ",\n")
	  "\n}\n")]
	[(list? json)
	 (string-append  "["
			 (string-intersperse (map json->string json) ",")
			 "]\n")]
	[(number? json)
	 (number->string json)]
	[(string? json)
	 (string-append "\""
			(list->string (fold-right
					  (lambda (x acc)
					    (let ([q (assq x special)])
					      (if q (cons #\\ (cons (cdr q) acc))
						(cons x acc))))
					'()
					(string->list json)))
			"\"" )]
	[(bytevector? json)
	 (utf8->string json)]
        [(eq? json #t) "true"]
        [(eq? json #f) "false"]
        [(null? json) "null"]
	[(symbol? json)
	 (json->string (symbol->string json))]
	[else
	 (json->string "")]))