从文件返回单词列表

Question

我的下一个项目是写一个绞刑者游戏。我认为它可以帮助我温习字符串和文件I/O。

目前，我只能将字符串文件读入列表。我正在尝试避免使用全局变量，所以有人能给我指出正确的方向，使这些(可能是损坏的)代码变成一个返回列表的函数吗？

(defun read-word-list ()
  "Returns a list of words read in from a file."
  (let ((word-list (make-array 0 
                 :adjustable t
                 :fill-pointer 0)))
       (with-open-file (stream #p"wordlist.txt")
     (loop for line = (read-line stream)
        while line
          (push line word-list)))
       (select-target-word word-list)))))

Answer 1

您只需几行代码即可将单词读入为Lisp符号：

(defun read-words (file-name)
    (with-open-file (stream file-name)
      (loop while (peek-char nil stream nil nil)
           collect (read stream))))

示例输入文件- words.txt：

attack attempt attention attraction authority automatic awake 
bright broken brother brown brush bucket building 
comfort committee common company comparison competition

正在读取文件：

> (read-words "words.txt")
=> (ATTACK ATTEMPT ATTENTION ATTRACTION AUTHORITY AUTOMATIC AWAKE BRIGHT BROKEN BROTHER BROWN BRUSH BUCKET BUILDING COMFORT COMMITTEE COMMON COMPANY COMPARISON COMPETITION)

可以通过将符号括在竖线(|)中或将其声明为字符串来保留大小写：

|attack| "attempt" ...

阅读时不失大小写：

> (read-words "words.txt")
=> (|attack| "attempt" ...)

Answer 2

如果单词是每行一个，你可以这样做：

(defun file-words (file)
  (with-open-file (stream file)
    (loop for word = (read-line stream nil)
          while word collect word)))

然后你可以像这样使用它；

(file-words "/usr/share/dict/words")