emacs - 如何以交互方式读取两个输入并在函数调用中使用它们

Question

我目前正在学习 elisp 类(class)，所以我没有这门语言的经验。我试图以交互方式读取两个输入(矩形的宽度和长度)，然后使用它们调用函数来计算矩形的面积。我的代码如下:

(defun rectangle_Area(w l)
"Compute the area of a rectangle, given its width and length  interactively."
(interactive "nWidth: ")
(interactive "nLength: ")
(setq area (rectangleArea w l))      
(message "The rectangle's area is %f." area))

目前我收到参数数量错误错误。就像我说的，我以前没有经验......我真正需要知道的是如何使用交互式存储/读取两个单独的值。

感谢您的帮助

Answer 1

C-hf 交互式 RET:

To get several arguments, concatenate the individual strings, separating them by newline characters.

所以我们有:

(defun rectangle_Area(w l)
    "Compute the area of a rectangle, given its width and length  interactively."
    (interactive "nWidth: \nnLength: ")
    (setq area (rectangleArea w l))      
    (message "The rectangle's area is %f." area))