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Re: FW: [External] : Re: Is there symbol-plist functionality in Emacs Li
From: |
Jean Louis |
Subject: |
Re: FW: [External] : Re: Is there symbol-plist functionality in Emacs Lisp? |
Date: |
Sat, 8 May 2021 19:23:35 +0300 |
User-agent: |
Mutt/2.0.6 (2021-03-06) |
* Drew Adams <drew.adams@oracle.com> [2021-05-08 17:39]:
> As for how to get the function def, the answer
> is `symbol-function', AFAIK.
That is it.
(symbol-function 'rcd-markdown) ⇒ (closure (t) (text) "Markdown processing" (if
text (rcd-command-output-from-input "markdown" text) ""))
I see what it means in the manual:
,----
| Currently, an Emacs Lisp closure object is represented by a list with
| the symbol ‘closure’ as the first element, a list representing the
| lexical environment as the second element, and the argument list and
| body forms as the remaining elements:
|
| ;; lexical binding is enabled.
| (lambda (x) (* x x))
| ⇒ (closure (t) (x) (* x x))
`----
If not defined under lexical scoping it looks like:
(symbol-function 'myfn) ⇒ (lambda (a) a)
Thank you, yhat is good enough, as it is list and I can, under
conditions, change it to become able to save the function. It
serves tracking of some unused and soon to be deleted functions.
(defun save-function (f)
(let* ((fun (symbol-function f))
(type (car fun)))
(cond ((eq type 'lambda) (setq fun (append (list 'defun f) (cdr fun))))
((eq type 'closure) (setq fun (append (list 'defun f) (nthcdr 2
fun)))))
;; save to file comes here
fun))
(defun myfn (a) (+ 2 2 a))
(save-function 'myfn) ⇒ (defun myfn (a) (+ 2 2 a))
(save-function 'rcd-markdown) ⇒ (defun rcd-markdown (text) "Markdown
processing" (if text (rcd-command-output-from-input "markdown" text) ""))
(defun string-to-file-force (string file)
"Prints string into file, matters not if file exists. Returns FILE as file
name."
(with-temp-file file
(insert string))
file)
Then now I can save at least those functions defined by myself, it
serves my long term introspection, and preservation of single, from
file deleted functions.
(defun save-function ()
(interactive)
(let ((function (function-called-at-point)))
(when (and (symbolp function)
(y-or-n-p (format "Save `%s'" (symbol-name function))))
(let* ((fun (symbol-function function))
(type (car fun))
(file (concat "/tmp/function-" (symbol-name function) ".el")))
(cond ((eq type 'lambda) (setq fun (append (list 'defun function) (cdr
fun))))
((eq type 'closure) (setq fun (append (list 'defun function) (nthcdr
2 fun)))))
(message (string-to-file-force (prin1-to-string fun) file))))))
(define-key emacs-lisp-mode-map (kbd "<f6>") 'save-function)
It gives output like this, that is acceptable:
(defun save-function nil (interactive) (let (#'(function-called-at-point)) (if
(and (symbolp function) (y-or-n-p (format "Save `%s'" (symbol-name function))))
(progn (let* ((fun (symbol-function function)) (type (car fun)) (file (concat
"/tmp/function-" (symbol-name function) ".el"))) (cond ((eq type 'lambda) (setq
fun (append (list 'defun function) (cdr fun)))) ((eq type 'closure) (setq fun
(append (list 'defun function) (nthcdr 2 fun))))) (message
(string-to-file-force (prin1-to-string fun) file)))))))
--
Jean
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