* setcdr question @ 2013-07-01 22:46 drain 2013-07-02 2:12 ` Pierre Lorenzon 2013-07-02 9:06 ` Nicolas Richard 0 siblings, 2 replies; 9+ messages in thread From: drain @ 2013-07-01 22:46 UTC (permalink / raw) To: Help-gnu-emacs (setq list '(Trevor Jason John Alex Max)) (setcdr (nthcdr (1- 4) list) 'Christina) list "list" is now set to: (Trevor Jason John Alex . Christina) Why is the dot there? -- View this message in context: http://emacs.1067599.n5.nabble.com/setcdr-question-tp290941.html Sent from the Emacs - Help mailing list archive at Nabble.com. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-01 22:46 setcdr question drain @ 2013-07-02 2:12 ` Pierre Lorenzon 2013-07-02 9:06 ` Nicolas Richard 1 sibling, 0 replies; 9+ messages in thread From: Pierre Lorenzon @ 2013-07-02 2:12 UTC (permalink / raw) To: aeuster; +Cc: Help-gnu-emacs From: drain <aeuster@gmail.com> Subject: setcdr question Date: Mon, 1 Jul 2013 15:46:10 -0700 (PDT) > (setq list '(Trevor Jason John Alex Max)) > > (setcdr (nthcdr (1- 4) list) 'Christina) > > list > > "list" is now set to: > > (Trevor Jason John Alex . Christina) > > Why is the dot there? Because you should have issued : (setcdr (nthcdr (1- 4) list) '(Christina)) See how lists are made from cons cell. The cdr should always be a list itself or nil at the end. Regards Pierre > > > > -- > View this message in context: http://emacs.1067599.n5.nabble.com/setcdr-question-tp290941.html > Sent from the Emacs - Help mailing list archive at Nabble.com. > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-01 22:46 setcdr question drain 2013-07-02 2:12 ` Pierre Lorenzon @ 2013-07-02 9:06 ` Nicolas Richard 2013-07-02 9:17 ` Teemu Likonen 1 sibling, 1 reply; 9+ messages in thread From: Nicolas Richard @ 2013-07-02 9:06 UTC (permalink / raw) To: drain; +Cc: Help-gnu-emacs drain <aeuster@gmail.com> writes: > (setq list '(Trevor Jason John Alex Max)) > (setcdr (nthcdr (1- 4) list) 'Christina) As your question was already answered, I allow me to digress slightly in suggesting that you may like setf for such operations: (let ((list '(Trevor Jason John Alex Max))) (setf (nth (1- 4) list) 'Christina) list) => (Trevor Jason John Christina Max) -- Nico. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-02 9:06 ` Nicolas Richard @ 2013-07-02 9:17 ` Teemu Likonen 2013-07-02 22:17 ` drain 0 siblings, 1 reply; 9+ messages in thread From: Teemu Likonen @ 2013-07-02 9:17 UTC (permalink / raw) To: Nicolas Richard; +Cc: drain, Help-gnu-emacs [-- Attachment #1: Type: text/plain, Size: 553 bytes --] Nicolas Richard [2013-07-02 11:06:58 +02:00] wrote: > drain <aeuster@gmail.com> writes: >> (setq list '(Trevor Jason John Alex Max)) >> (setcdr (nthcdr (1- 4) list) 'Christina) > (let ((list '(Trevor Jason John Alex Max))) > (setf (nth (1- 4) list) 'Christina) > list) In Common Lisp a literal data shouldn't be edited. I suggest adopting the same practice in Emacs Lisp too. So, create your list with LIST (list 'Trevor 'Jason 'John 'Alex 'Max) or copy a literal sequence before editing: (copy-sequence '(Trevor Jason John Alex Max)) [-- Attachment #2: Type: application/pgp-signature, Size: 835 bytes --] ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-02 9:17 ` Teemu Likonen @ 2013-07-02 22:17 ` drain 2013-07-02 22:26 ` drain ` (2 more replies) 0 siblings, 3 replies; 9+ messages in thread From: drain @ 2013-07-02 22:17 UTC (permalink / raw) To: Help-gnu-emacs Appreciate the answers. However, where is the dot coming from? What is that supposed to represent? -- View this message in context: http://emacs.1067599.n5.nabble.com/setcdr-question-tp290941p291014.html Sent from the Emacs - Help mailing list archive at Nabble.com. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-02 22:17 ` drain @ 2013-07-02 22:26 ` drain 2013-07-03 9:13 ` Pierre Lorenzon [not found] ` <mailman.90.1372804018.12400.help-gnu-emacs@gnu.org> 2 siblings, 0 replies; 9+ messages in thread From: drain @ 2013-07-02 22:26 UTC (permalink / raw) To: Help-gnu-emacs Ignore. Figured out. That was pure laziness; apologies. -- View this message in context: http://emacs.1067599.n5.nabble.com/setcdr-question-tp290941p291016.html Sent from the Emacs - Help mailing list archive at Nabble.com. ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-02 22:17 ` drain 2013-07-02 22:26 ` drain @ 2013-07-03 9:13 ` Pierre Lorenzon [not found] ` <mailman.90.1372804018.12400.help-gnu-emacs@gnu.org> 2 siblings, 0 replies; 9+ messages in thread From: Pierre Lorenzon @ 2013-07-03 9:13 UTC (permalink / raw) To: aeuster; +Cc: Help-gnu-emacs From: drain <aeuster@gmail.com> Subject: Re: setcdr question Date: Tue, 2 Jul 2013 15:17:11 -0700 (PDT) > Appreciate the answers. > > However, where is the dot coming from? What is that supposed to represent? A cons cell : (cons 'a 'b) => (a . b) Regards Pierre > > > > -- > View this message in context: http://emacs.1067599.n5.nabble.com/setcdr-question-tp290941p291014.html > Sent from the Emacs - Help mailing list archive at Nabble.com. > ^ permalink raw reply [flat|nested] 9+ messages in thread
[parent not found: <mailman.90.1372804018.12400.help-gnu-emacs@gnu.org>]
* Re: setcdr question [not found] ` <mailman.90.1372804018.12400.help-gnu-emacs@gnu.org> @ 2013-07-03 13:04 ` Rustom Mody 2013-07-04 19:19 ` drain 0 siblings, 1 reply; 9+ messages in thread From: Rustom Mody @ 2013-07-03 13:04 UTC (permalink / raw) To: help-gnu-emacs On Wednesday, July 3, 2013 3:56:54 AM UTC+5:30, drain wrote: > Ignore. Figured out. > That was pure laziness; apologies. Asking this question is the initiatory rite of starting lisp :-) ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: setcdr question 2013-07-03 13:04 ` Rustom Mody @ 2013-07-04 19:19 ` drain 0 siblings, 0 replies; 9+ messages in thread From: drain @ 2013-07-04 19:19 UTC (permalink / raw) To: Help-gnu-emacs Things really open up once car / cons / cdr / nth / nthcdr are properly understood. I had so much inefficient code before! Emacs über alles. -- View this message in context: http://emacs.1067599.n5.nabble.com/setcdr-question-tp290941p291234.html Sent from the Emacs - Help mailing list archive at Nabble.com. ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2013-07-04 19:19 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
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2013-07-01 22:46 setcdr question drain
2013-07-02 2:12 ` Pierre Lorenzon
2013-07-02 9:06 ` Nicolas Richard
2013-07-02 9:17 ` Teemu Likonen
2013-07-02 22:17 ` drain
2013-07-02 22:26 ` drain
2013-07-03 9:13 ` Pierre Lorenzon
[not found] ` <mailman.90.1372804018.12400.help-gnu-emacs@gnu.org>
2013-07-03 13:04 ` Rustom Mody
2013-07-04 19:19 ` drain
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