Question

此lisp代码应采用常规数字及其罗马等效文件1=I等文件，并从中创建一个点对(1 . I)的大列，然后将该alist写入文件。< / p>

(defun arabic_to_roman (filename)
     (let ((arab_roman_dp '())
           (arab nil)
           (roman nil)
           (in (open filename :if-does-not-exist nil)))

       (when in
         (loop for line = (read-line in nil)
               while line do
               (setq arab (subseq line 0 (search "=" line)))
               (setq roman (subseq line (1+ (search "=" line)) (length line)))
               (setf arab_roman_dp (acons arab roman arab_roman_dp))
               (format t "~S ~S~%" arab roman)))
         (close in)

         (with-open-file (stream #p"ar_out.txt"
                                 :direction :output
                                 :if-exists :overwrite
                                 :if-does-not-exist :create )
           (format stream arab_roman_dp))
                                           ;(format t "~S"  arab_roman_dp)
         ))

在slime / sbcl中生成此错误：

in: DEFUN ARABIC_TO_ROMAN
;     (FORMAT STREAM ARAB_ROMAN_DP)
; 
; caught WARNING:
;   Derived type of ARAB_ROMAN_DP is
;     (VALUES LIST &OPTIONAL),
;   conflicting with its asserted type
;     (OR (VECTOR CHARACTER) (VECTOR NIL) BASE-STRING FUNCTION).
;   See also:
;     The SBCL Manual, Node "Handling of Types"

在我放入(format stream arab_roman_dp)

之前，评论行（最后一个）工作正常

这是输入文件的示例：

1=I
2=II
3=III
4=IV=IIII
5=V
6=VI
7=VII
8=VIII=IIX
9=IX=VIIII
10=X
11=XI
12=XII
13=XIII

...

4994=MMMMCMXCIV
4995=MMMMCMXCV
4996=MMMMCMXCVI
4997=MMMMCMXCVII
4998=MMMMCMXCVIII
4999=MMMMCMXCIX

不确定我在这里做错了什么。基本上，我想把我创建的点对的大列表写到文件中。

((4999 . MMMMCMXCIX) (4998 . MMMMCMXCVIII) ... (1 . I))

Answer 1

FORMAT的第二个参数必须是控制字符串。代码中的第二个参数arab_roman_dp是一个列表。 SBCL可以检测到这个错误，并且正确发出此代码的警告信号。

常见的lisp：写入文件抱怨类型

1 个答案: