From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?B?xaB0xJtww6FuIE7Em21lYw==?= Subject: Re: [babel] What is `, (backquote comma)? Date: Wed, 21 Sep 2011 20:46:18 +0200 Message-ID: <871uv9hgxx.fsf@gmail.com> References: <867h51x0d5.fsf@googlemail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([140.186.70.92]:46940) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R6RtP-0002us-KL for emacs-orgmode@gnu.org; Wed, 21 Sep 2011 14:51:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R6RtO-000610-JA for emacs-orgmode@gnu.org; Wed, 21 Sep 2011 14:51:35 -0400 Received: from mail-fx0-f41.google.com ([209.85.161.41]:49827) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R6RtO-00060g-Bm for emacs-orgmode@gnu.org; Wed, 21 Sep 2011 14:51:34 -0400 Received: by fxh17 with SMTP id 17so2250643fxh.0 for ; Wed, 21 Sep 2011 11:51:33 -0700 (PDT) In-Reply-To: <867h51x0d5.fsf@googlemail.com> (Thorsten's message of "Wed, 21 Sep 2011 19:37:42 +0200") List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: Thorsten Cc: emacs-orgmode@gnu.org On Wed, 21 Sep 2011 19:37:42 +0200 Thorsten wrote: > in org-babel-expand-body:scheme (and > e.g. org-babel-expand-body:emacs-lisp) I encounter something like this: > > (lambda (var) (format "%S" (print `(,(car var) ',(cdr var))))) >=20=09 > While this part > `(,(car var) ...) > is explained in the manual (backquote and unquote), this part > `(... ',(cdr var)) > is a bit mysterious to me, and I do not find information about > backquote( ... backquote comma ()) > in the manuals or the web. > > Is that Emacs Lisp? What does that mean? Note it's not "`,", which would indeed be a no-op, but "',", which here means "evaluate the form after "," and quote the result", IOW, the "'" is just left there (for the same reason you also get to see the even more funny-looking "`'," and other variations sometimes). Really nothing new if you've read the backquote section of the Elisp manual. --=20 =C5=A0t=C4=9Bp=C3=A1n