From: "Pascal J. Bourguignon" <pjb@informatimago.com>
To: help-gnu-emacs@gnu.org
Subject: Re: How to flatten a one-level-deep list?
Date: Wed, 18 May 2016 19:52:21 +0200 [thread overview]
Message-ID: <8737pffe3u.fsf@kuiper.lan.informatimago.com> (raw)
In-Reply-To: mailman.46.1463559697.6543.help-gnu-emacs@gnu.org
<tomas@tuxteam.de> writes:
> On Wed, May 18, 2016 at 07:12:56AM +0200, Marcin Borkowski wrote:
>> Hi,
>>
>> I have a list of lists of atoms, and I want to have a flat list
>> containing these atoms. I could use -flatten from dash.el, but I'd
>> prefer not to introduce such a dependency for this one function alone.
>> Is there anything *in core Emacs* to do it, or should I just write my
>> own version?
>
> (setq l '((a b c) (d e f) (g h i)))
> (apply 'append l)
> => (a b c d e f g h i)
>
> No idea whether performance or edge cases match your requirements,
> though :)
append will refer to the last list in that literal list, thus making the
result half literal. This may be a problem or not, depending on how you
use this result.
You can use concatenate (cl-concatenate) instead, if you want to copy
even the last subsequence:
(apply 'concatenate 'list l)
--> (a b c d e f g h i)
--
__Pascal Bourguignon__ http://www.informatimago.com/
“The factory of the future will have only two employees, a man and a
dog. The man will be there to feed the dog. The dog will be there to
keep the man from touching the equipment.” -- Carl Bass CEO Autodesk
prev parent reply other threads:[~2016-05-18 17:52 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-18 5:12 How to flatten a one-level-deep list? Marcin Borkowski
2016-05-18 8:21 ` tomas
2016-05-18 9:37 ` Marcin Borkowski
2016-05-18 21:07 ` Emanuel Berg
2016-05-20 12:17 ` Stefan Monnier
2016-05-20 15:01 ` Michael Heerdegen
2016-05-20 17:20 ` Marcin Borkowski
2016-05-20 17:54 ` Michael Heerdegen
2016-05-20 19:51 ` Marcin Borkowski
2016-05-20 22:14 ` Michael Heerdegen
[not found] ` <mailman.46.1463559697.6543.help-gnu-emacs@gnu.org>
2016-05-18 17:52 ` Pascal J. Bourguignon [this message]
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