修复 HTDP 练习 200 的 "read-itunes-as-list: expects a file with XML document as first argument, given "itunes.xml""

Question

我正在做 HtDP Exercises, and I'm having trouble on Exercise 200。我按照书上说的做了，但我一直犯同样的错误。无论我尝试什么，我总是得到这个：

read-itunes-as-list: expects a file with XML document as first argument, given "itunes.xml"

我尝试过更改 itunes.xml 的名称和其他一些操作，但它们似乎都失败了。有人知道如何解决这个问题吗？这是我的代码（到目前为止）：

; An LTracks is one of:
; – '()
; – (cons Track LTracks)
; Example:
;   (cons (make-track "Wild Child" "Enya" "A Day Without" 227996 2 (make-date 2002 7 17 3 55 14) 20 (make-date 2011 5 17 17 35 13))
;         '())

;(define-struct track
;  [name artist album time track# added play# played])
; A Track is a structure:
;   (make-track String String String N N Date N Date)
; interpretation An instance records in order: the track's 
; title, its producing artist, to which album it belongs, 
; its playing time in milliseconds, its position within the 
; album, the date it was added, how often it has been 
; played, and the date when it was last played
; Example:
;   (make-track "Wild Child" "Enya" "A Day Without" 227996 2 (make-date 2002 7 17 3 55 14) 20 (make-date 2011 5 17 17 35 13))

;(define-struct date [year month day hour minute second])
; A Date is a structure:
;   (make-date N N N N N N)
; interpretation An instance records six pieces of information:
; the date's year, month (between 1 and 12 inclusive), 
; day (between 1 and 31), hour (between 0 
; and 23), minute (between 0 and 59), and 
; second (also between 0 and 59).
; Example:
;   (make-date 2019 7 9 20 35 54)

; modify the following to use your chosen name
(define ITUNES-LOCATION "itunes.xml")

; LTracks
(define itunes-tracks
  (read-itunes-as-tracks ITUNES-LOCATION))

和itunes.xml：

<dict>
    <key>Track ID</key><integer>442</integer>
    <key>Name</key><string>Wild Child</string>
    <key>Artist</key><string>Enya</string>
    <key>Album</key><string>A Day Without</string>
    <key>Genre</key><string>New Age</string>
    <key>Kind</key><string>MPEG audio file</string>
    <key>Size</key><integer>4562044</integer>
    <key>Total Time</key><integer>227996</integer>
    <key>Track Number</key><integer>2</integer>
    <key>Track Count</key><integer>11</integer>
    <key>Year</key><integer>2000</integer>
    <key>Date Added</key><date>2002-7-17T3:55:14</date>
    <key>Play Count</key><integer>20</integer>
    <key>Play Date</key><integer>3388484113</integer>
    <key>Play Date UTC</key><date>2011-5-17T17:35:13
</dict>

Answer 1

正如我在评论中提到的，您的 itunes.xml 格式错误。例如，

在最后一行的前一行，你有 <date> 但没有相应的结束标记 </date>。
日期格式错误。例如，2002-7-17T3:55:14 应更改为 2002-07-17T03:55:14。

如果您从 https://gist.github.com/sorawee/e92eada7d3081b308c5e9fefbcb3def3 下载 itunes.xml 并改为使用它，它应该可以正常工作。

您从哪里以及如何获得原件 itunes.xml？

修复 HTDP 练习 200 的 "read-itunes-as-list: expects a file with XML document as first argument, given "itunes.xml""

Fixing "read-itunes-as-list: expects a file with XML document as first argument, given "itunes.xml"" for HTDP exercise 200

racket

itunes

htdp