unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
From: <tomas@tuxteam.de>
To: help-gnu-emacs@gnu.org
Subject: Re: Replace element in list
Date: Mon, 2 Sep 2019 12:37:23 +0200	[thread overview]
Message-ID: <20190902103723.GC1466@tuxteam.de> (raw)
In-Reply-To: <6a632b18-bbd6-7096-229d-6c890b6bdb6f@easy-emacs.de>

[-- Attachment #1: Type: text/plain, Size: 515 bytes --]

On Mon, Sep 02, 2019 at 11:44:10AM +0200, Andreas Röhler wrote:
> Hi,
> 
> is there a recommended way to replace element x at index i of
> somelist  y by newelement?

Like this?

  scheme@(guile-user)> (define lst (list-copy '(fire water air earth)))
  scheme@(guile-user)> (list-set! lst 2 'mud)
  $3 = mud
  scheme@(guile-user)> lst
  $4 = (fire water mud earth)
  
Note the "list-copy" above. Strange things might happen to your computer
if you try to mutate immutable data ;-D

Cheers
-- t

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 198 bytes --]

  reply	other threads:[~2019-09-02 10:37 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-02  9:44 Replace element in list Andreas Röhler
2019-09-02 10:37 ` tomas [this message]
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
  -- strict thread matches above, loose matches on Subject: below --
2018-11-22  4:42 replace " 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
     [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

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=20190902103723.GC1466@tuxteam.de \
    --to=tomas@tuxteam.de \
    --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).