From: asparagus@comcast.net
To: 19896@debbugs.gnu.org
Subject: bug#19896: 23.1; reverse-region is slow compared to sort-columns
Date: Wed, 18 Feb 2015 17:35:42 +0000 (UTC) [thread overview]
Message-ID: <758739999.5853607.1424280942368.JavaMail.zimbra@comcast.net> (raw)
In-Reply-To: <1372534272.5818344.1424278471675.JavaMail.zimbra@comcast.net>
The emacs manual recommends 'M-x reverse-region' as a companion to 'M-x sort-columns' to achieve a descending-order column sort. However, for large regions (>100k lines), 'M-x reverse-region' is noticeably slower than 'M-x sort-columns', making descending sort much slower than ascending sort.
A workaround on linux: use 'C-u M-x shell-command-on-region' with tac (the opposite of cat) instead of using 'M-x reverse-region'.
FROM THE MANUAL:
https://www.gnu.org/software/emacs/manual/html_node/emacs/Sorting.html
M-x reverse-region
Reverse the order of the lines in the region. This is useful for sorting into descending order by fields or columns, since those sort commands do not have a feature for doing that.
next parent reply other threads:[~2015-02-18 17:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1372534272.5818344.1424278471675.JavaMail.zimbra@comcast.net>
2015-02-18 17:35 ` asparagus [this message]
2015-02-18 18:29 ` bug#19896: 23.1; reverse-region is slow compared to sort-columns Ivan Shmakov
2015-02-18 19:01 ` Eli Zaretskii
2015-02-18 19:13 ` Ivan Shmakov
2015-02-18 19:29 ` Eli Zaretskii
[not found] ` <1358494426.5913572.1424285832847.JavaMail.zimbra@comcast.net>
2015-02-18 19:19 ` bug#19896: asparagus
[not found] ` <215096857.10629626.1424972910085.JavaMail.zimbra@comcast.net>
2015-02-26 17:53 ` bug#19896: Please modify documentation to close this bug asparagus
2015-04-19 0:49 ` Glenn Morris
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