From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric Schulte" Subject: Re: Re: Babel, Python and UTF-8 Date: Sun, 05 Dec 2010 08:30:53 -0700 Message-ID: <87mxokz176.fsf@gmail.com> References: <87fwuhas6t.fsf@gmail.com> <80bp54a693.fsf@missioncriticalit.com> <87hbew7yvi.fsf@gmail.com> <80k4jsszq4.fsf@missioncriticalit.com> <8739qf2ade.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from [140.186.70.92] (port=58923 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PPGYQ-00079H-Ur for emacs-orgmode@gnu.org; Sun, 05 Dec 2010 10:31:21 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PPGYF-0006qW-Ko for emacs-orgmode@gnu.org; Sun, 05 Dec 2010 10:31:10 -0500 Received: from mail-gy0-f169.google.com ([209.85.160.169]:45693) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PPGYF-0006qD-Fo for emacs-orgmode@gnu.org; Sun, 05 Dec 2010 10:30:59 -0500 Received: by gyg10 with SMTP id 10so20413262gyg.0 for ; Sun, 05 Dec 2010 07:30:58 -0800 (PST) In-Reply-To: (Vincent Beffara's message of "Fri, 03 Dec 2010 16:43:23 +0100") List-Id: "General discussions about Org-mode." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org Errors-To: emacs-orgmode-bounces+geo-emacs-orgmode=m.gmane.org@gnu.org To: Vincent Beffara Cc: emacs-orgmode@gnu.org Vincent Beffara writes: > Hi, > >>> (and it would be excellent to allow for a code block as a preamble, >>> instead of a string in the header or as an alternative, because >>> preambles once they are allowed tend to grow uncontrollably ;->) >> >> This is currently possible using the `sbe' function. Arbitrary emacs >> lisp can be placed inside of header arguments, and the `sbe' take the >> name of a code block and returns its result. > > Very cool ! That does all I want, thanks for the info. For multi-line it > is a bit heavy to write, with lots of \n and preamble .=3D "lskjd", but I > can live with that. Unless there is a way already to write something > like this ? > > #+source: my-preamble > #+begin_src python :return preamble > # -*- coding: utf-8 -*-" > import os,sys,whatever > #+end_src > > #+begin_src python :preamble (org-babel-get-and-expand-source-code-body m= y-preamble) :return s > s =3D "=C3=A9" > #+end_src > > There is org-babel-get-src-block-info but it looks at the block around > (point), not by name ... so I guess it would not be too hard to write > the extraction method, but it might be somewhere in the code already. > Yes, the following uses an internal Babel function, but is probably much simpler #+results: my-preamble : # -*- coding: utf-8 -*- : import os,sys,whatever #+begin_src python :preamble (org-babel-ref-resolve "my-preamble") :return s s =3D "=C3=A9" #+end_src Note that as written this will return the following python error Traceback (most recent call last): File "", line 2, in ImportError: No module named whatever > >>> One naive question : why is the code path different for tangling and >>> evaluation ? One would think that a natural way for evaluation would be >>> to tangle the current block (plus included noweb stuff etc) into a >>> temporary file and eval that file ... and that would enable shebang for >>> evaluation as well. There must be something I am missing here. >> >> Tangling works for *any* programming language, even those which have yet >> to be created and have no explicit Emacs or Org-mode support, this is >> because on tangling the code block is simply treated as text. > > As far as I understood from testing, tangling does adapt to the language > (at least to implement :var in a suitable way), so I was under the > impression that evaluating could be implemented as some kind of wrapping > around the tangled output - and obviously the wrapping would have to be > language-specific even if for the most part the tanglong is not. > Yes, some language specific features (e.g. variable expansion) can be used by the tangling mechanisms if such features are defined for the language in question, however tangling can be done in the absence of any language specific features and thus works for any arbitrary language. That shebang and preamble should remain separate for the other reasons mentioned in my previous email. > > I am just discovering all of this, sorry if I have horrible > misconceptions about the thing ... > No problem, it is a fairly (but I don't think overly) complex system. > > Regards, > > /v > > > _______________________________________________ > Emacs-orgmode mailing list > Please use `Reply All' to send replies to the list. > Emacs-orgmode@gnu.org > http://lists.gnu.org/mailman/listinfo/emacs-orgmode