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From: Gregory Heytings <gregory@heytings.org>
To: Emanuel Berg <moasenwood@zoho.eu>
Cc: help-gnu-emacs@gnu.org
Subject: Re: Lexical vs. dynamic: small examples?
Date: Sat, 14 Aug 2021 20:23:35 +0000	[thread overview]
Message-ID: <4a9bddb9ec23089cd1f6@heytings.org> (raw)
In-Reply-To: <87mtpj3hpj.fsf@zoho.eu>


>> (defvar saved-buffer-read-only)
>> (defun delete-whitespace-at-eol ()
>>   (interactive)
>>   (setq saved-buffer-read-only buffer-read-only)
>>   (setq buffer-read-only nil)
>>   (save-excursion (replace-regexp " *$" "" nil (point-min) (point-max)))
>>   (setq buffer-read-only saved-buffer-read-only))
>
> OK, but you don't need to store the old value in a global variable...
>

Of course you do, you need to restore the original value, which could be 
either t or nil.  But indeed TIMTOWTDI: for this specific example, another 
way to do it would be to introduce a conditional.  In general however 
variables can hold more than two values, so for didactic purposes the 
above is much clearer.



  reply	other threads:[~2021-08-14 20:23 UTC|newest]

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-14  3:34 Lexical vs. dynamic: small examples? Eduardo Ochs
2021-08-14  3:56 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14  4:12   ` Eduardo Ochs
2021-08-14  7:35 ` tomas
2021-08-14 16:00   ` Eduardo Ochs
2021-08-14 19:41     ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:42     ` tomas
2021-08-14 19:31   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:31     ` tomas
2021-08-14 21:26       ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 21:29         ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 13:35 ` [External] : " Drew Adams
2021-08-14 16:15   ` Eduardo Ochs
2021-08-14 19:00 ` Gregory Heytings
2021-08-14 20:16   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:23     ` Gregory Heytings [this message]
2021-08-14 21:05       ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 21:13         ` tomas
2021-08-14 21:28           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-14 20:41   ` tomas
2021-08-15  0:29   ` [External] : " Drew Adams
2021-08-15  0:52     ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15  1:04     ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15  1:18     ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15  4:44       ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15  5:02         ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 15:49         ` Drew Adams
2021-08-15 18:49           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 21:55             ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-15 22:04               ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 21:57             ` Drew Adams
2021-08-15 22:20               ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:54                 ` Drew Adams
2021-08-15 23:16               ` Drew Adams
2022-01-09  7:08                 ` Jean Louis
2022-01-09 15:03                   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 23:42               ` Arthur Miller
2021-08-15 22:02             ` Lars Ingebrigtsen
2021-08-15 22:22               ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:44                 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-21  3:38                   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-24  2:08                     ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-25 23:34                       ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-25 23:40                         ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-26  0:10                           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-26  0:44                             ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-26 17:01                               ` FW: " Drew Adams
2021-08-26 23:05                                 ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-25 23:46                         ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-25 23:47                         ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-26  0:57                           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-28  1:36                           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-28  1:41                           ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:44               ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 22:58                 ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-15 23:13                   ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 23:56                     ` Stefan Monnier via Users list for the GNU Emacs text editor
2021-08-16  0:43                       ` Emanuel Berg via Users list for the GNU Emacs text editor
2021-08-15 15:42       ` FW: " Drew Adams
  -- strict thread matches above, loose matches on Subject: below --
2022-01-09 17:40 Drew Adams
2022-01-10 13:10 ` Emanuel Berg via Users list for the GNU Emacs text editor

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