emacs - Emacs Lisp 中的动态变量

Question

我的代码看起来像这样

(defun work ()
  (interactive)
  (case major-mode
    ('javascript-mode (setq js-indent-level (if (eq js-indent-level 2) 4 2)))
    ('css-mode (setq cssm-indent-level (if (eq cssm-indent-level 2) 4 2)))
    ('nxml-mode (setq nxml-child-indent (if (eq nxml-child-indent 2) 4 2)))
    (t (setq c-basic-offset (if (eq c-basic-offset 2) 4 2)))))

在 2 级和 4 级缩进级别之间切换(我使用 4 个缩进空间，但需要 2 个缩进空间来工作)，是否可以将每行代码缩小为看起来相同的内容:

(defun work ()
  (interactive)
  (let ((var (case major-mode
                 ('javascript-mode 'js-indent-level)
                 ('css-mode 'cssm-indent-level)
                 ('nxml-mode 'nxml-child-indent)
                 (t 'c-basic-offset))))
     ;; like C pointers
     (setf (pointer var) (if (eq (pointer var) 2) 4 2))))

或

(defun work ()
  (interactive)
  (let ((var (cdr (assoc major-mode indent-vars))))
     (setf (pointer var) (if (eq (pointer var) 2) 4 2))))

如果我的缩进变量在 indent-vars alist 中

我需要使用宏还是 eval 才能做到这一点吗？

Answer 1

您需要symbol-value和 set .

(defun work ()
  (interactive)
  (let ((var (cdr (assoc major-mode indent-vars))))
     (set var (if (eq (symbol-value var) 2) 4 2))))