如何在lisp中同时获取两个输入？(how to take two input simultaneously in lisp?)

如何在lisp中同时获取两个输入？(how to take two input simultaneously in lisp?)

我想添加两个用户在Lisp中输入的数字。 我怎样才能做到这一点？ 我使用了read命令两次，但是显示错误。

I want to add two numbers that are to be entered by the user in Lisp. How can I do that? I used the read command twice but it shows an error.

最满意答案

我建议使用parse-number库从用户输入中parse-number 。 使用read代替用户可以直接访问您不需要的Lisp阅读器。

像这样的东西应该工作：

(defun prompt-number (prompt &optional (prompt-stream *standard-output*) (read-stream *standard-input*)) (format prompt-stream "~a: " prompt) (parse-number:parse-number (read-line read-stream)))

I recommend parsing numbers from user input with the parse-number library. Using read instead gives the user direct access to the Lisp reader, which you do not want.

Something like this should work:

(defun prompt-number (prompt &optional (prompt-stream *standard-output*) (read-stream *standard-input*)) (format prompt-stream "~a: " prompt) (parse-number:parse-number (read-line read-stream)))