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* Add a filter function to emacs
@ 2010-07-07 19:45 Rolando Pereira
  2010-07-08  6:36 ` Geoff Gole
  2010-07-08  9:12 ` Deniz Dogan
  0 siblings, 2 replies; 3+ messages in thread
From: Rolando Pereira @ 2010-07-07 19:45 UTC (permalink / raw)
  To: emacs-devel

Hello,

I would like to know if there is a reason for the lack of a filter
function on the emacs code base.

According to the Elisp Cookbook on the Emacs Wiki, it seems that it
would be simple to implement:

  (defun my-filter (condp lst)
    (delq nil
          (mapcar (lambda (x) (and (funcall condp x) x)) lst)))
;; From http://www.emacswiki.org/emacs/ElispCookbook

Shouldn't this function be in the regular emacs code base (maybe in the
lisp/simple.el file)?

Is there any problem with it?



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Add a filter function to emacs
  2010-07-07 19:45 Add a filter function to emacs Rolando Pereira
@ 2010-07-08  6:36 ` Geoff Gole
  2010-07-08  9:12 ` Deniz Dogan
  1 sibling, 0 replies; 3+ messages in thread
From: Geoff Gole @ 2010-07-08  6:36 UTC (permalink / raw)
  To: Rolando Pereira; +Cc: emacs-devel

>
> I would like to know if there is a reason for the lack of a filter
> function on the emacs code base.
>

See remove-if and remove-if-not in cl.el.



^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: Add a filter function to emacs
  2010-07-07 19:45 Add a filter function to emacs Rolando Pereira
  2010-07-08  6:36 ` Geoff Gole
@ 2010-07-08  9:12 ` Deniz Dogan
  1 sibling, 0 replies; 3+ messages in thread
From: Deniz Dogan @ 2010-07-08  9:12 UTC (permalink / raw)
  To: Rolando Pereira; +Cc: emacs-devel

2010/7/7 Rolando Pereira <ei08150@fe.up.pt>:
> Hello,
>
> I would like to know if there is a reason for the lack of a filter
> function on the emacs code base.
>
> According to the Elisp Cookbook on the Emacs Wiki, it seems that it
> would be simple to implement:
>
>  (defun my-filter (condp lst)
>    (delq nil
>          (mapcar (lambda (x) (and (funcall condp x) x)) lst)))
> ;; From http://www.emacswiki.org/emacs/ElispCookbook
>
> Shouldn't this function be in the regular emacs code base (maybe in the
> lisp/simple.el file)?
>
> Is there any problem with it?
>
>

I brought this up some time ago as I found that many higher-order
functions were missing in (non-cl.el) Emacs. If I remember correctly,
it's the lack of lexical scoping that makes it difficult.

-- 
Deniz Dogan



^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-07-08  9:12 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
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2010-07-07 19:45 Add a filter function to emacs Rolando Pereira
2010-07-08  6:36 ` Geoff Gole
2010-07-08  9:12 ` Deniz Dogan

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