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From: Lennart Borgman <lennart.borgman@gmail.com>
To: Nordlöw <per.nordlow@gmail.com>
Cc: help-gnu-emacs@gnu.org
Subject: Re: Wanted: mapcar() without nils
Date: Sat, 13 Jun 2009 21:43:28 +0200	[thread overview]
Message-ID: <e01d8a50906131243w1af3c85cg4ab868f4d5dc1542@mail.gmail.com> (raw)
In-Reply-To: <65652541-cb7d-4c93-8baf-cd963990e57e@g1g2000yqh.googlegroups.com>

You misplaced a closing paren in the lambda

On Sat, Jun 13, 2009 at 8:24 PM, Nordlöw<per.nordlow@gmail.com> wrote:
> (defun extract-elements (pred seq)
>  "Extract a copy of SEQ containing all elements fullfilling
> PRED."
>  (delq nil (mapcar `(lambda (elm) (when (,pred elm)) elm) seq)))

 (delq nil (mapcar `(lambda (elm) (when (,pred elm) elm)) seq)))

> ;; Use: (extract-elements 'symbolp '(a b 1 2)) => '(a b)
> ;; Use: (extract-elements 'numberp '(a b 1 2)) => '(1 2)




  parent reply	other threads:[~2009-06-13 19:43 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-13 12:19 Wanted: mapcar() without nils Nordlöw
2009-06-13 12:47 ` Lennart Borgman
     [not found] ` <mailman.562.1244897231.2239.help-gnu-emacs@gnu.org>
2009-06-13 18:24   ` Nordlöw
2009-06-13 19:05     ` Thierry Volpiatto
     [not found]     ` <mailman.581.1244920367.2239.help-gnu-emacs@gnu.org>
2009-06-13 19:33       ` Nordlöw
2009-06-13 19:45         ` Nordlöw
2009-06-13 19:43     ` Lennart Borgman [this message]
2009-06-13 20:02     ` Drew Adams

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