Created
April 21, 2013 11:48
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The `add-hook-one-time` macro that doesn't work and some evaluation results.
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;;; The macro: | |
(defmacro add-hook-one-time (hook function) | |
"Add FUNCTION to HOOK. Remove it after its first execution." | |
(let ((wrapper-function (make-symbol "wrapper-function-symbol"))) | |
`(progn | |
(defun ,wrapper-function () | |
"Wrapper function that will be executed only once, and then removed from the hook." | |
(funcall ,function) | |
(remove-hook ,hook ,wrapper-function)) | |
(add-hook ,hook ,wrapper-function)))) | |
;;; Evaluated form: | |
(macroexpand | |
'(add-hook-one-time 'emacs-lisp-mode-hook | |
(lambda () | |
(message "Hello, world!")))) | |
;;; Result: | |
(progn | |
(defun wrapper-function-symbol nil | |
"Wrapper function that will be executed only once, and then removed from the hook." | |
(funcall | |
(lambda nil | |
(message "Hello, world!"))) | |
(remove-hook 'emacs-lisp-mode-hook wrapper-function-symbol)) | |
(add-hook 'emacs-lisp-mode-hook wrapper-function-symbol)) | |
;;; Evaluated form: | |
(add-hook-one-time 'emacs-lisp-mode-hook | |
(lambda () (message "Hello, world!"))) | |
;;; Error: | |
Symbol's value as variable is void: wrapper-function-symbol |
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