From: Michael Heerdegen <michael_heerdegen@web.de>
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 08:10:21 +0200 [thread overview]
Message-ID: <87edur6tyq.fsf@web.de> (raw)
In-Reply-To: jwvy1t0m7c2.fsf-monnier+emacs@gnu.org
Stefan Monnier via Users list for the GNU Emacs text editor
<help-gnu-emacs@gnu.org> writes:
> PS: For the curious, here's what the above `named-let` expands to:
>
> (defalias 'has-non-nil
> #'(lambda (lst)
> (let ((lst lst))
> (let (retval)
> (while
> (let ((lst lst))
> (cond
> ((null lst) nil)
> ((consp lst) (let ((val (not (null (car lst)))))
> (if val (progn (setq retval val) nil)
> (progn (setq lst (cdr lst)) :recurse))))
> (t (progn (setq retval (error "Not a proper list! You cheater!"))
> nil)))))
> retval))))
Is that :recurse symbol only there to improve readability, or is it
handled specially?
Michael.
next prev parent reply other threads:[~2022-10-29 6:10 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 [this message]
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
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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