如何使用Lisp将数字列表转换为分隔字符串

Question

给定以下代码：

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Copyright (C) 2014  Wojciech Siewierski                               ;;
;;                                                                       ;;
;; This program is free software: you can redistribute it and/or modify  ;;
;; it under the terms of the GNU General Public License as published by  ;;
;; the Free Software Foundation, either version 3 of the License, or     ;;
;; (at your option) any later version.                                   ;;
;;                                                                       ;;
;; This program is distributed in the hope that it will be useful,       ;;
;; but WITHOUT ANY WARRANTY; without even the implied warranty of        ;;
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         ;;
;; GNU General Public License for more details.                          ;;
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;; You should have received a copy of the GNU General Public License     ;;
;; along with this program.  If not, see <http://www.gnu.org/licenses/>. ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defvar *output*)
(defvar *indent*)
(defun format-tag (symbol &optional arg)
(cond
((equal arg 'begin)
(format nil "~{~a~}<~(~a~)" *indent* symbol))
((equal arg 'end)
(format nil "~{~a~}<~(/~a~)>~%" *indent* symbol))
(t
(format nil "~{~a~}~a~%" *indent* symbol))))
(defun sexp-to-xml--inside-tag (sexp)
(if sexp
(if (listp (car sexp))
(progn
(sexp-to-xml--new-tag (car sexp))
(sexp-to-xml--inside-tag (cdr sexp)))
(progn
(push (format-tag
(string (car sexp)))
*output*)
(sexp-to-xml--inside-tag (cdr sexp))))))
(defun sexp-to-xml--attrs (plist)
(when plist
(push (format nil " ~(~a~)=~s"
(car plist)
(cadr plist))
*output*)
(sexp-to-xml--attrs (cddr plist))))
(defun sexp-to-xml--new-tag (sexp)
(if (listp (car sexp))
(progn
(push (format-tag (caar sexp) 'begin)
*output*)
(sexp-to-xml--attrs (cdar sexp)))
(push (format-tag (car sexp) 'begin)
*output*))
(unless (cdr sexp)
(push (format nil " /")
*output*))
(push (format nil ">~%")
*output*)
(let ((*indent* (cons "  " *indent*)))
(sexp-to-xml--inside-tag (cdr sexp)))
(when (cdr sexp)
(push (format-tag (if (listp (car sexp))
(caar sexp)
(car sexp))
'end)
*output*)))
(defun sexp-to-xml-unquoted (&rest sexps)
(apply #'concatenate 'string
(apply #'concatenate 'list
(loop for sexp in sexps collecting
(let ((*output* nil)
(*indent* nil))
(reverse (sexp-to-xml--new-tag  sexp)))))))
(defmacro sexp-to-xml (&rest sexps)
`(format *standard-output* "~a"
(sexp-to-xml-unquoted ,@(loop for sexp in sexps collecting
`(quote ,sexp)))))
(defun file-get-contents (filename)
(with-open-file (stream filename)
(let ((contents (make-string (file-length stream))))
(read-sequence contents stream)
contents)))
(defun file-get-lines (filename)
(with-open-file (stream filename)
(loop for line = (read-line stream nil)
while line
collect line)))
(defun list-to-string (lst)
(format nil "~{~A~}" lst))

(defun test1()
(let((input (file-get-contents "sample2.sexp")))
(format t (sexp-to-xml-unquoted (read-from-string "(head (title "my-site"))")))
)
)
(defun test2()
(let((input (file-get-lines "sample2.sexp")))
(loop for sexp in input do (print (write-to-string sexp)))
)
)
(defun test3()
(let((input (file-get-lines "sample2.sexp")))
(format t (list-to-string input))
)
)

(defun :str->lst (str / i lst)
(repeat (setq i (strlen str))
(setq lst (cons (substr str (1+ (setq i (1- i))) 1) lst)))) 
(defun print-elements-recursively (list)
(when list                            ; do-again-test
(print (car list))              ; body
(print-elements-recursively     ; recursive call
(cdr list))))                  ; next-step-expression

(defun tokenize( str )(read-from-string (concatenate 'string "(" str
")")))

(defun test4()
(let((input (file-get-contents "sample2.sexp")))
(print-elements-recursively (tokenize input) )
)
)

(defun test5()
(let((input (file-get-contents "sample2.sexp")))
(print (sexp-to-xml-unquoted (tokenize input)))
)
)
(defun test6()
(let((input (file-get-contents "sample2.sexp")))
(loop for sexp in  (tokenize input) do (
with-input-from-string (s (write-to-string sexp) ) 
(print ( sexp-to-xml-unquoted (read s)) )
)
)
)
)

(defun test7()
(let((input (file-get-contents "sample2.sexp")))
(loop for sexp in  (tokenize input) do (
print sexp
)
)
)
)
(defun test8()
(let((input (file-get-contents "sample2.sexp")))
(format t (sexp-to-xml-unquoted (read-from-string input)))
)
)

我想序列化成一个xml文件，特别是这个示例文件：

(supertux-tiles
(tilegroup
(name (_ "Snow"))
(tiles
7    8    9    202
13   14   15   204
10   11   12   206
16   17   18   205
30   31   114  113
21   22   19   203
20   23   207  208
3044 3045 3046 3047
3048 3049 3050 3051
3052 3053 3054 3055
3056 3057 3058 3059
2134 115  116  214
2135 117  118  1539
3249 3250 3251 3252
3253 3254 3255 3256
3261 3262 3263 3264
3265 3266 3267 3268
2121 2122 2123 0
2126 2127 2128 0
2131 2132 2133 0
2124 2125 0    0
2129 2130 0    0
2909 2910 2913 2914
2911 2912 2915 2916
1834    0    0 1835
2917 2918 2921 2922
2919 2920 2923 2924
0 1826 1827    0
1829 1830 1831 1832
1833 1834 1835 1836
3139 3140 3141 3142
3143 3144 3145 3146
0 3147 3148    0
3149    0    0 3150
3151 3152 3153 3154
3155 3156 3157 3158
0 1835 1834    0
1837 1838 1843 1844
1839 1840 1845 1846
1841 1842 1847 1848
0    0 1849 1850
2925 2926 2929 2930
0    2928 2931 0
0    0    2937 2940
2933 2935 2938 2941
2934 2936 2939 2942
2050 2051 2060 2061
2055 2056 2065 2066
2052 2053 2054 0
2057 2058 2059 0
2062 2063 2064 0
0 2067 2068 2069
0 2072 2073 2074
2075 2079 2076 2070
2077 2073 2078 2071
2178 3038 3039 3040
2406 3041 3042 3043
2155 2156 2157 2163
2158 2159 2154 2164
2160 2161 2162 2165
2166 2167 2168 2169
2170 2171 2172 2173
2174 2175 2176 2177
2384 2385 2386 2949
2387 2388 2389 2950
2390 2391 2392 2951
2393 2394 2395 2952
2953 2954 2955 2956
2957 2962 2398 2396
2958 2961 2399 2397
2959 2960 2997 2998
0    0    2963 2969
2975 2979 2964 2970
2976 2980 2965 2971
2977 2981 2966 2972
2978 2982 2967 2973
0    0    2968 2974
0    2986 2990 0
2983 2987 2991 2994
2984 2988 2992 2995
2985 2989 2993 2996
33   32   34   1741
35   37   39   1740
38   36   43   1739
40   41   42   1815
119  121  120  1816
)
)
)

但使用test8会出现一个错误：

7 is not a string designator.

这让我写了一个这样的文件：

(超晚礼服瓷砖(波浪组(名称(_"雪"((瓷砖"7")))

然后编译得很好，生成xml，但我不知道如何将所有整数转换为它们的字符串表示，从列表中读取。我试着解析字符串并使用write-to-string方法，但我觉得我遗漏了一些东西。

任何帮助都会被激怒。

谢谢！

--编辑--

根据coredump的建议，将带princ的字符串更改为字符串可以修复字符串中原始数字的解析评估，然而，当试图评估t等符号时，会发生以下情况：

no dispatch function defined for #T

以以下为例

(tile
; dupe of tile 70, this one will be removed.
(id 63)
(deprecated #t)
(images
"tilesets/background/backgroundtile1.png"
)
)

不过，看起来对Lisp之外的变量的求值将只通过检查"t"xml标记来保持。

这个问题解决了。

Answer 1

在谷歌上快速搜索可找到以下存储库(https://github.com/Vifon/sexp-to-xml/blob/master/sexp-to-xml.lisp)；链接的代码足以重现错误。注意，当我从Emacs/Slime内部运行它时，调试器会显示回溯：

0: (STRING 7)
1: (SEXP-TO-XML--INSIDE-TAG (7 8 9 202 13 14 ...))
2: (SEXP-TO-XML--NEW-TAG (TILES 7 8 9 202 13 ...))
3: (SEXP-TO-XML--INSIDE-TAG ((TILES 7 8 9 202 13 ...)))
4: (SEXP-TO-XML--INSIDE-TAG ((NAME (_ "Snow")) (TILES 7 8 9 202 13 ...)))
5: (SEXP-TO-XML--NEW-TAG (TILEGROUP (NAME (_ "Snow")) (TILES 7 8 9 202 13 ...)))
6: (SEXP-TO-XML--INSIDE-TAG ((TILEGROUP (NAME #) (TILES 7 8 9 202 13 ...))))
7: (SEXP-TO-XML--NEW-TAG (SUPERTUX-TILES (TILEGROUP (NAME #) (TILES 7 8 9 202 13 ...))))
8: (SEXP-TO-XML-UNQUOTED (SUPERTUX-TILES (TILEGROUP (NAME #) (TILES 7 8 9 202 13 ...))))

在上面列出的各种堆栈帧上按v，我可以在调用堆栈中找到当前代码停止的位置。

我没有加载lisp文件，只是评估了当前Emacs缓冲区中的不同形式，因此没有与函数相关的源文件。然而，AST表单是为了调试而存储的，调试器可以精确定位代码执行的当前位置，并封装在一个伪(#:***HERE*** ...)表单中：

(SB-INT:NAMED-LAMBDA SEXP-TO-XML--INSIDE-TAG
(SEXP)
(BLOCK SEXP-TO-XML--INSIDE-TAG
(IF SEXP
(IF (LISTP (CAR SEXP))
(PROGN
(SEXP-TO-XML--NEW-TAG (CAR SEXP))
(SEXP-TO-XML--INSIDE-TAG (CDR SEXP)))
(PROGN
(PUSH (FORMAT-TAG (#:***HERE*** (STRING (CAR SEXP)))) *OUTPUT*)
(SEXP-TO-XML--INSIDE-TAG (CDR SEXP)))))))

对任意值调用string将不起作用，您需要在sexp-to-xml--inside-tag中将其替换为princ-to-string。然后它按预期工作。