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From: Drew Adams <drew.adams@oracle.com>
To: Marcin Borkowski <mbork@mbork.pl>, Emanuel Berg <moasenwood@zoho.eu>
Cc: "help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
Subject: RE: [External] : Re: Is there a way of setting a variable only when it exists?
Date: Tue, 15 Mar 2022 15:38:12 +0000	[thread overview]
Message-ID: <SJ0PR10MB5488396D40AE9345B6F5121CF3109@SJ0PR10MB5488.namprd10.prod.outlook.com> (raw)
In-Reply-To: <87a6drviwp.fsf@mbork.pl>

> What if it's an internal Emacs variable which might become a user
> option one day (I submitted a bug report about it) and then my
> customization silently disappears?  It's the "silently" part I
> want to guard against...

What do you mean by "an internal Emacs variable"?

If it's a defvar then Emacs's predefined defvar
has no effect if you defvar the variable before
Emacs does.  And it has no effect if you setq
the var before or after Emacs defvars it (as long
as Emacs doesn't _use_ it before you setq it).

If Emacs later changes it to a defcustom, the
same things apply.  However, if the defcustom has
a :set function then your own setting of it might
no longer be appropriate ("valid").



  parent reply	other threads:[~2022-03-15 15:38 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-14  6:00 Is there a way of setting a variable only when it exists? Marcin Borkowski
2022-03-14 12:52 ` Eli Zaretskii
2022-03-14 13:16 ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-03-14 13:48   ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-15  6:17     ` Marcin Borkowski
2022-03-15  6:50       ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-15  6:58       ` Jean Louis
2022-03-15  7:45         ` Marcin Borkowski
2022-03-15  8:12           ` Jean Louis
2022-03-15  7:49         ` tomas
2022-03-15  8:13           ` Jean Louis
2022-03-15  8:36             ` tomas
2022-03-15  9:28               ` Jean Louis
2022-03-15 10:01                 ` tomas
2022-03-15 11:29                 ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-15  8:14           ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-15 15:33         ` [External] : " Drew Adams
2022-03-15 15:38       ` Drew Adams [this message]
2022-03-16 18:32         ` Marcin Borkowski
2022-03-16  0:47       ` Michael Heerdegen
2022-03-16 18:33         ` Marcin Borkowski
2022-03-16  6:02       ` Tomas Nordin
2022-03-16  6:37         ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-16 18:34         ` Marcin Borkowski
2022-03-15  6:48     ` Jean Louis
2022-03-14 22:09 ` Michael Heerdegen
2022-03-15  6:16   ` Marcin Borkowski
2022-03-15  7:05     ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-16  0:25     ` Michael Heerdegen
2022-03-16 18:33       ` Marcin Borkowski
2022-03-16 19:25         ` Michael Heerdegen
2022-03-18  5:58           ` Marcin Borkowski
2022-03-16 20:35         ` Emanuel Berg via Users list for the GNU Emacs text editor
2022-03-17 20:47           ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-03-18  5:59             ` Marcin Borkowski
2022-03-18 17:59           ` Jean Louis
2022-03-19  9:25             ` Emanuel Berg via Users list for the GNU Emacs text editor

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