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From: Alan Mackenzie <acm@muc.de>
To: Robert Pluim <rpluim@gmail.com>
Cc: emacs-devel@gnu.org
Subject: Re: Is there already an alist function which gets all matching elements,  not just the first?
Date: Thu, 6 Oct 2022 18:24:29 +0000	[thread overview]
Message-ID: <Yz8dXUYJ1YQYsbH9@ACM> (raw)
In-Reply-To: <87bkqq8s7n.fsf@gmail.com>

Hello, Robert.

On Wed, Oct 05, 2022 at 12:45:00 +0200, Robert Pluim wrote:
> >>>>> On Wed, 5 Oct 2022 10:00:10 +0000, Alan Mackenzie <acm@muc.de> said:

>     Alan> Hello, Emacs.
>     Alan> I want to be able to get all matching elements from an alist (thinking
>     Alan> about extending imenu).  Something like

>     Alan>     (assoc-all key list)

>     Alan> which would return a list of matches.  After all, we have functions
>     Alan> which _delete_ all matches from an alist.

>     Alan> Does such a function already exist, perhaps in cl-*.el?

> Just use assoc-delete-all and invert the test:

> (assoc-delete-all mykey myalist (lambda (val key)
>                                   (not (eq val key))))

Thanks for the idea!  But I'd have to copy the alist first, and then it
starts to look a bit contrived.

Maybe I should just write a straightforward loop to get this info.

> Robert
> -- 

-- 
Alan Mackenzie (Nuremberg, Germany).



  reply	other threads:[~2022-10-06 18:24 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-05 10:00 Is there already an alist function which gets all matching elements, not just the first? Alan Mackenzie
2022-10-05 10:45 ` Robert Pluim
2022-10-06 18:24   ` Alan Mackenzie [this message]
2022-10-05 18:16 ` Philip Kaludercic
2022-10-05 18:35   ` Lars Ingebrigtsen
2022-10-06 18:34   ` Alan Mackenzie

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