修正“read as -list:期望使用XML文档作为第一个参数的文件，在HTDP练习200中给出”itunes.xml“。

Question

我正在做HtDP练习，而我在练习200上遇到了麻烦。我照书告诉我的做了，但我一直犯同样的错误。不管我做了什么，我总能做到：

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，以及其他一些东西，但它们似乎都失败了。有人知道怎么解决这个问题吗？下面是我的代码(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格式不正确。例如,

• 在最后一行之前的行中，您有<date>，但是没有相应的结束标记</date>。
• 日期格式是错误的。例如，2002-7-17T3:55:14应该改为2002-07-17T03:55:14。

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

你在哪里以及如何获得你的原始itunes.xml