如何在方案中写入相同的显示(printf)文件? [英] how to write alike display (printf) to file in scheme?

问题描述

使用TinyScheme.

Using TinyScheme.

我正在将代码写入文件(在此处以50％的比例解决:如何使用tinyscheme写入文件?)，方法如下:

I'm writing my code to file (solved it in 50% here: How to write to a file in tinyscheme?) with:

(with-output-to-file "biophilia.c"
  (lambda ()
    (write code)
    ))
; and segmentation fault comes here

但是它按原样使用" qotes和\ n \ r编写我的代码，因此不会将其转换为换行符.

but it writes my code with "" qotes and \n\r as is so it doesn't translate it to newline.

我需要编写类似(display code)

，例如

in example in racket docs there is printf but seems like TinyScheme implementation got no printf, maybe I need to discover (add code of it) printf?

推荐答案

找到解决方案，唯一的解决方法是将put-char挂到write-char

Found solution, the only fix is ex-hanged put-char to write-char

  (define assert
    (lambda (aa msg)
      (if (null? aa)
    #t
    (if (not (car aa))
      (error msg)
      (assert (cdr aa) msg))))) 

 (display "define fprintf\n\r")
(define (fprintf port f . args)
   (let ((len (string-length f)))
     (let loop ((i 0) (args args))
       (cond ((= i len) (assert (null? args)))
         ((and (char=? (string-ref f i) #\~)
           (< (+ i 1) len))
          (dispatch-format (string-ref f (+ i 1)) port (car args))
          (loop (+ i 2) (cdr args)))
         (else
          (write-char (string-ref f i) port)
          (loop (+ i 1) args))))))

(display "define printf\n\r")
(define (printf f . args)
   (let ((port (current-output-port)))
     (apply fprintf port f args)
     (flush-output-port port)))

    (display "writing to output file biophilia.c\n\r")
    (with-output-to-file "biophilia.c"
      (lambda ()
        (printf code)
        ))

代码不再出现段错误

但在文件末尾:错误:(:25)参数不足

but in the end of file: Error: ( : 25) not enough arguments

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