From: Michael Heerdegen <michael_heerdegen@web.de>
To: help-gnu-emacs@gnu.org
Subject: Re: How to save custom variable programmatically?
Date: Tue, 10 Nov 2020 22:15:58 +0100 [thread overview]
Message-ID: <87h7pwgbg1.fsf@web.de> (raw)
In-Reply-To: X6rnuNu08WlXrwLi@protected.rcdrun.com
Jean Louis <bugs@gnu.support> writes:
> Thank you. If you have ready simplest example it may be useful for
> review.
Simplest? Ok, that might be possible. Let's make a wrapper holding a
single value that is savable:
#+begin_src emacs-lisp
(defclass my-persistent (eieio-persistent)
((data :initarg :data)))
(defun my-save-in-location (thing file)
(let ((obj (my-persistent :data thing)))
(setf (oref obj file) file)
(eieio-persistent-save obj)))
;; save a value to a file:
(my-save-in-location (list 'x [] "Hello")
(expand-file-name "~/test"))
;; get it back:
(oref (eieio-persistent-read
(expand-file-name "~/test")
'my-persistent)
:data)
;; ==> (x [] "Hello")
#+end_src
This is not only a nice abstraction. eieio-persistent has some
(programmable) knowledge about how to print and "restore" objects where
a normal print+read cycle would not work.
Michael.
next prev parent reply other threads:[~2020-11-10 21:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 7:51 How to save custom variable programmatically? Jean Louis
2020-11-10 10:43 ` Robert Pluim
2020-11-10 13:42 ` Jean Louis
2020-11-10 11:23 ` Michael Heerdegen
2020-11-10 13:55 ` Jean Louis
2020-11-10 14:36 ` Michael Heerdegen
2020-11-10 19:19 ` Jean Louis
2020-11-10 20:42 ` Marcin Borkowski
2020-11-10 21:46 ` Jean Louis
2020-11-11 21:20 ` Marcin Borkowski
2020-11-10 20:43 ` Michael Heerdegen
2020-11-10 21:52 ` Jean Louis
2020-11-11 18:00 ` Michael Heerdegen
2020-11-11 18:05 ` Jean Louis
2020-11-17 12:24 ` Michael Heerdegen
2020-11-17 15:07 ` Jean Louis
2020-11-10 21:15 ` Michael Heerdegen [this message]
2020-11-10 21:55 ` Jean Louis
2020-11-11 10:55 ` Michael Heerdegen
2020-11-17 15:44 ` Jean Louis
2020-11-17 16:38 ` Michael Heerdegen
2020-11-17 21:30 ` Stefan Monnier
2020-11-10 16:24 ` Drew Adams
2020-11-10 19:23 ` Jean Louis
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