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From: Stefan Monnier <monnier@IRO.UMontreal.CA>
To: David Kastrup <dak@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: `save-excursion' defeated by `set-buffer'
Date: Tue, 22 Dec 2009 19:45:25 -0500	[thread overview]
Message-ID: <jwvpr672k5p.fsf-monnier+emacs@gnu.org> (raw)
In-Reply-To: <876380nvnt.fsf@lola.goethe.zz> (David Kastrup's message of "Mon,  21 Dec 2009 17:23:18 +0100")

>> So either you want to use
>> 
>> (save-current-buffer (set-buffer foo) (goto-char (point-min)))
>> aka
>> (with-current-buffer foo (goto-char (point-min)))

> Says who?

I, based on my experience.

> You mean "so either you _could_ use".  But save-excursion
> does save the mark in the current buffer, and it does save point and
> mark of the current buffer.

> Please check the difference of
> (with-temp-buffer
>   (let ((buf1 (current-buffer)))
>      (insert "xxxx")
>      (prin1 (point))
>      (save-excursion
>        (with-temp-buffer
>           (with-current-buffer buf1
>             (goto-char (point-min)))))
>      (prin1 (point))))
> and
> (with-temp-buffer
>   (let ((buf1 (current-buffer)))
>      (insert "xxxx")
>      (prin1 (point))
>      (with-temp-buffer
>         (with-current-buffer buf1
>           (goto-char (point-min))))
>      (prin1 (point))))

> You'll see that save-excursion restores point (and mark) even when
> temporarily moving into some other buffer.

Irrelevant: neither example uses (save-excursion (set-buffer ..) ...).

>> if moving point in foo is what you wanted, or
>> (with-current-buffer foo (save-excursion (goto-char (point-min))))
>> if you didn't want to move point in foo.

> And what if I wanted to have mark, point, and buffer restored, as the

Obviously "if you didn't want to move point in foo" implies that you did
not want "to have mark, point, and buffer restored".


        Stefan




  parent reply	other threads:[~2009-12-23  0:45 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-20 19:19 `save-excursion' defeated by `set-buffer' Roland Winkler
2009-12-21 15:26 ` Stefan Monnier
2009-12-21 16:23   ` David Kastrup
2009-12-22 12:51     ` martin rudalics
2009-12-23  0:45     ` Stefan Monnier [this message]
2009-12-23  9:07       ` David Kastrup
2009-12-24  4:35         ` Stefan Monnier
2009-12-24  9:03           ` David Kastrup
2009-12-29 16:01             ` Stefan Monnier
2010-01-04  9:09               ` Drew Adams
2010-01-04 18:30                 ` Stefan Monnier
2010-01-05 20:17                   ` David Kastrup
2010-01-06  0:02                     ` Drew Adams
2010-01-06  4:20                       ` Stefan Monnier
2010-01-06  8:07                         ` David Kastrup
2010-01-06  8:57                           ` Drew Adams
2010-01-10  4:57                             ` Stefan Monnier
2010-01-10  8:12                               ` David Kastrup
2010-01-10 21:43                                 ` Stefan Monnier
2010-01-11  8:24                                   ` David Kastrup
2010-01-11  9:21                                     ` martin rudalics
2010-01-11 16:50                                       ` Stefan Monnier
2010-01-10 17:03                               ` Drew Adams
2010-01-10  4:51                           ` Stefan Monnier
2010-01-10 15:58                         ` Harald Hanche-Olsen
2010-01-10 18:05                           ` martin rudalics
2010-01-10 18:06                           ` Drew Adams
2010-01-10 19:44                             ` Harald Hanche-Olsen
2009-12-24 14:04   ` Roland Winkler
2010-01-04 17:08   ` Davis Herring
2010-01-04 17:34     ` David Kastrup
2010-01-04 18:33     ` Stefan Monnier
  -- strict thread matches above, loose matches on Subject: below --
2009-12-18  9:20 Eli Zaretskii
2009-12-18 15:29 ` Juanma Barranquero
2009-12-18 15:58   ` Thierry Volpiatto

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