From: Emanuel Berg <incal@dataswamp.org>
To: help-gnu-emacs@gnu.org
Subject: Re: [External] : Re: Testing whether a list contains at least one non-nil element
Date: Sat, 29 Oct 2022 11:20:10 +0200 [thread overview]
Message-ID: <87r0yr56lx.fsf@dataswamp.org> (raw)
In-Reply-To: 87lep031vm.fsf@web.de
Michael Heerdegen wrote:
>> If you are doing it "by hand", why not indulge in Lisp's
>> "classic elegance", like so:
>>
>> (defun has-non-nil (lst)
>> (cond
>> ((null lst) nil)
>> ((consp lst) (or (not (null (car lst))) (has-non-nil (cdr lst))))
>> (t (error "Not a proper list! You cheater!"))))
>
> You don't want to implement such functions in Emacs with
> recursion because you'll easily hit `max-lisp-eval-depth'
> when they are called. Sorry to tell you, but a loop is the
> preferable way in Elisp.
He knows that ...
>
--
underground experts united
https://dataswamp.org/~incal
next prev parent reply other threads:[~2022-10-29 9:20 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-25 10:16 Testing whether a list contains at least one non-nil element Heime
2022-10-25 10:46 ` Jean Louis
2022-10-25 10:47 ` Jean Louis
2022-10-25 10:50 ` Jean Louis
2022-10-25 12:12 ` Emanuel Berg
2022-10-26 18:56 ` Jean Louis
2022-10-27 3:54 ` [External] : " Drew Adams
2022-10-27 4:53 ` Jean Louis
2022-10-27 5:30 ` Emanuel Berg
2022-10-27 15:54 ` Drew Adams
2022-10-27 17:47 ` Elisp and CL (was: Re: [External] : Re: Testing whether a list contains at least one non-nil element) Emanuel Berg
2022-10-27 20:38 ` [External] : Re: Testing whether a list contains at least one non-nil element Jean Louis
2022-10-28 0:22 ` Emanuel Berg
2022-10-28 4:48 ` tomas
2022-10-28 5:19 ` Jean Louis
2022-10-28 6:20 ` Michael Heerdegen
2022-10-28 13:09 ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-10-29 6:10 ` Michael Heerdegen
2022-10-29 15:25 ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-10-30 12:49 ` Emanuel Berg
2022-10-29 6:38 ` tomas
2022-10-30 12:48 ` Emanuel Berg
2022-10-29 9:20 ` Emanuel Berg [this message]
2022-10-29 9:19 ` Emanuel Berg
2022-10-27 4:01 ` Emanuel Berg
2022-10-25 12:05 ` Michael Heerdegen
2022-10-25 12:15 ` Emanuel Berg
2022-10-25 15:59 ` [External] : " Drew Adams
2022-10-25 17:44 ` Emanuel Berg
2022-10-26 15:39 ` Drew Adams
2022-10-26 17:43 ` Emanuel Berg
2022-10-25 17:25 ` Joost Kremers
2022-10-25 17:51 ` Emanuel Berg
2022-10-25 19:44 ` Heime
2022-10-25 20:08 ` Joost Kremers
2022-10-25 20:15 ` [External] : " Drew Adams
2022-10-25 20:19 ` Joost Kremers
2022-10-26 3:00 ` Stefan Monnier via Users list for the GNU Emacs text editor
-- strict thread matches above, loose matches on Subject: below --
2022-10-28 5:07 Drew Adams
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