3 秒后清除
(message "Some message")
(run-with-timer 3 nil (lambda () (message nil)))
Emacs RIME
Minor Mode
https://www.gnu.org/software/emacs/manual/html_node/elisp/Defining-Minor-Modes.html
(define-minor-mode hungry-mode
"Toggle Hungry mode.
Interactively with no argument, this command toggles the mode.
A positive prefix argument enables the mode, any other prefix
argument disables it. From Lisp, argument omitted or nil enables
the mode, `toggle' toggles the state.
When Hungry mode is enabled, the control delete key
gobbles all preceding whitespace except the last.
See the command \\[hungry-electric-delete]."
;; The initial value.
nil
;; The indicator for the mode line.
" Hungry"
;; The minor mode bindings.
'(([C-backspace] . hungry-electric-delete)))