unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
From: Stefan Monnier <monnier@iro.umontreal.ca>
To: help-gnu-emacs@gnu.org
Subject: Re: replace element in list
Date: Thu, 22 Nov 2018 08:19:49 -0500	[thread overview]
Message-ID: <jwvh8g9uu8t.fsf-monnier+gmane.emacs.help@gnu.org> (raw)
In-Reply-To: 2087821187f90948d25d93c7ea475e66@openmail.cc

> I want to share and know if there is a better way (more efficient or
> clearer) to replace something within a list (I don't know LISP).

My suggestion is to not do it:
- if you do it by modifying the list in place, it means you're using
  nasty side-effects, which are better avoided when possible
  (especially with lists).
- if you want to do it without side-effects, your operation will
  inevitably be algorithmically inefficient because a list is not
  designed for that.


-- Stefan




  parent reply	other threads:[~2018-11-22 13:19 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-22  4:42 replace element in list edgar
2018-11-22  5:18 ` Eric Abrahamsen
2018-11-22  5:39   ` Drew Adams
2018-11-22  6:04     ` Eric Abrahamsen
2018-11-22 13:19 ` Stefan Monnier [this message]
     [not found] ` <mailman.4442.1542892802.1284.help-gnu-emacs@gnu.org>
2018-11-23 12:05   ` Robert Munyer
2018-11-24  3:01 ` edgar
2018-11-24  5:27   ` Drew Adams
2018-11-24  7:22     ` edgar
  -- strict thread matches above, loose matches on Subject: below --
2019-09-02  9:44 Replace " Andreas Röhler
2019-09-02 10:37 ` tomas
2019-09-02 10:41   ` tomas
2019-09-02 10:46     ` tomas
2019-09-02 11:03       ` Michael Heerdegen
2019-09-02 11:05         ` tomas
2019-09-02 13:38           ` Andreas Röhler
2019-09-02 13:29 ` Stefan Monnier
2019-09-02 13:43   ` tomas
2019-09-02 14:00     ` Andreas Röhler
2019-09-02 14:57       ` Stefan Monnier
2019-09-02 20:29         ` Andreas Röhler
2019-09-02 21:32           ` Stefan Monnier
2019-09-03  5:37             ` Andreas Röhler

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=jwvh8g9uu8t.fsf-monnier+gmane.emacs.help@gnu.org \
    --to=monnier@iro.umontreal.ca \
    --cc=help-gnu-emacs@gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).