对Lisp中的char列表进行排序(Sorting a list of char in Lisp)

对Lisp中的char列表进行排序(Sorting a list of char in Lisp)

有没有一种方法可以按字母顺序（从“a”到“z”）排序仅由字符组成的列表，如：（list cmayk）=>（list ackmy）？

我没有找到这样的排序，所以我认为这可以解决问题：

cl-prompt> (setq q (mapcar 'string '(c m a y k))) => ("C" "M" "A" "Y" "K") cl-prompt> (sort q 'string<) => ("A" "C" "K" "M" "Y")

在这一点上我卡住了，因为通过使用char转换器输出将不会是我想要的列表。 例：

char (string 'a) 0 => #\A

我将有一个列表：（＃\ A＃\ C＃\ K＃\ M＃\ Y），这不是我想要的结果。

Is there a way to sort a list made of only characters in alphabetic order (from "a" to "z"), such as: (list c m a y k) => (list a c k m y)?

I didn't found a sort like that, so i thought this could solve the problem:

cl-prompt> (setq q (mapcar 'string '(c m a y k))) => ("C" "M" "A" "Y" "K") cl-prompt> (sort q 'string<) => ("A" "C" "K" "M" "Y")

At this point i'm stuck, because by using the char converter the output will not be the list i want. Example:

char (string 'a) 0 => #\A

And i will have a list made of: (#\A #\C #\K #\M #\Y), which is not the result i want.

最满意答案

在(cmayk)的情况下，你有一个符号列表。 在(#\A #\C #\K #\M #\Y) ，您有一个字符列表。

如果你想根据符号名称对符号列表进行排序，你可以这样做（我假设列表绑定到下面的变量foo）：

(setq foo (sort foo #'string< :key #'symbol-name))

请注意:key #'symbol-name可能被认为是多余的，因为string<实际上是在“字符串指示符”上操作的，但是对于读者来说，您确实打算基于符号名称对列表进行排序如果你明确地这样说。

In the case of (c m a y k), you have a list of symbols. In the case of (#\A #\C #\K #\M #\Y), you have a list of characters.

If you want to sort a list of symbols according to the symbol names, you can do (I am assuming the list is bound to the variable foo below):

(setq foo (sort foo #'string< :key #'symbol-name))

Note that the :key #'symbol-name could be argued to be superfluous, as string< actually operates on "string designators", but it is much clearer to a human reader that you are indeed intending to sort the list based on symbol names if you say so explicitly.