From: Marcin Borkowski <mbork@mbork.pl>
To: Help Gnu Emacs mailing list <help-gnu-emacs@gnu.org>
Subject: How to delete all nil properties from a plist?
Date: Sun, 02 Aug 2015 00:03:50 +0200 [thread overview]
Message-ID: <87oaiq3buh.fsf@mbork.pl> (raw)
Hi all,
so I'm still using plists, though I'm less and less sure that they are
actually better than alists for my use-case. Now I need to delete all
properties whose value is nil. I'm using this function:
--8<---------------cut here---------------start------------->8---
(defun plist-clear (plist)
"Return PLIST with all nil properties deleted."
(cond
((< (length plist) 2) nil)
((null (cadr plist)) (cddr plist))
(t (cons (car plist) (cons (cadr plist) (plist-clear (cddr plist)))))))
--8<---------------cut here---------------end--------------->8---
Question 1: is there a better way to write it? (Especially the last
line.)
Question 2: how would I do the analogous thing with alists?
TIA,
--
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University
next reply other threads:[~2015-08-01 22:03 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-01 22:03 Marcin Borkowski [this message]
2015-08-01 22:11 ` How to delete all nil properties from a plist? Marcin Borkowski
2015-08-02 1:32 ` Emanuel Berg
[not found] ` <mailman.7753.1438479312.904.help-gnu-emacs@gnu.org>
2015-08-02 1:36 ` Pascal J. Bourguignon
2015-08-02 1:50 ` Emanuel Berg
2015-08-02 3:55 ` Rusi
2015-08-02 16:21 ` Pascal J. Bourguignon
[not found] ` <mailman.7754.1438480361.904.help-gnu-emacs@gnu.org>
2015-08-02 16:24 ` Pascal J. Bourguignon
2015-08-05 23:08 ` Emanuel Berg
[not found] ` <mailman.7864.1438816202.904.help-gnu-emacs@gnu.org>
2015-08-05 23:30 ` Pascal J. Bourguignon
2015-08-05 23:49 ` Emanuel Berg
2015-08-06 0:30 ` Emanuel Berg
2015-08-06 1:05 ` John Mastro
2015-08-06 1:07 ` John Mastro
[not found] ` <mailman.7867.1438818687.904.help-gnu-emacs@gnu.org>
2015-08-06 2:32 ` Pascal J. Bourguignon
2015-08-07 22:21 ` Emanuel Berg
[not found] ` <mailman.7869.1438821124.904.help-gnu-emacs@gnu.org>
2015-08-06 2:40 ` Pascal J. Bourguignon
2015-08-07 22:32 ` Emanuel Berg
[not found] ` <mailman.7963.1438986782.904.help-gnu-emacs@gnu.org>
2015-08-08 3:56 ` Pascal J. Bourguignon
2015-08-09 1:34 ` Emanuel Berg
[not found] ` <mailman.7996.1439084206.904.help-gnu-emacs@gnu.org>
2015-08-09 2:18 ` Pascal J. Bourguignon
2015-08-09 2:28 ` Emanuel Berg
[not found] ` <mailman.7749.1438467076.904.help-gnu-emacs@gnu.org>
2015-08-01 23:46 ` Pascal J. Bourguignon
[not found] <mailman.7748.1438466648.904.help-gnu-emacs@gnu.org>
2015-08-01 23:43 ` Pascal J. Bourguignon
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