From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Peter Neilson" Subject: Re: Chaining strings between babel blocks: why so many '\'? Date: Wed, 26 Mar 2014 19:35:00 -0400 Message-ID: References: <87bnwstxfs.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:43883) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSxLh-0000ZF-2M for emacs-orgmode@gnu.org; Wed, 26 Mar 2014 19:35:15 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WSxLa-0003he-TD for emacs-orgmode@gnu.org; Wed, 26 Mar 2014 19:35:08 -0400 Received: from pacmmta55.windstream.net ([162.39.147.221]:34079) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSxLa-0003fi-Mx for emacs-orgmode@gnu.org; Wed, 26 Mar 2014 19:35:02 -0400 In-Reply-To: <87bnwstxfs.fsf@gmail.com> 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: emacs-orgmode@gnu.org On Wed, 26 Mar 2014 18:19:35 -0400, Nicolas Goaziou wrote: > Hello, > > Alan Schmitt writes: > >> I've been playing with block chaining to generate some dot file then to >> export then as images. I had a little trouble finding the number of '\' >> I need to put in front of a quote if I want the quote to be quoted. Here >> is a way to make it work: >> >> #+name: foo >> #+begin_src emacs-lisp :exports none >> "bar [label = \"\\\\\"test1\\\\\"\"]\nbaz [label = >> \"\\\\\"test2\\\\\"\"]" >> #+end_src >> >> #+results: foo >> : bar [label = "\\"test1\\""] >> : baz [label = "\\"test2\\""] >> >> #+begin_src dot :file ~/tmp/test-dot.png :var input=foo :exports results >> graph { >> $input >> } >> #+end_src >> >> My question is: why can't I simply use this: >> >> #+name: foo >> #+begin_src emacs-lisp :exports none >> "bar [label = \"\\\"test1\\\"\"]\nbaz [label = \"\\\"test2\\\"\"]" >> #+end_src >> >> #+results: foo >> : bar [label = "\"test1\""] >> : baz [label = "\"test2\""] >> >> (I guess the answer is in the error in replace-regexp-in-string: >> (error "Invalid use of `\\' in replacement text") >> .) > > Indeed. This function, unless told not to, treats backslashes characters > specially. > >> Would it be problematic to first transform every "\\" into a "\\\\" in >> org-babel-expand-body:dot, before the call to >> replace-regexp-in-string? > > I think `replace-regexp-in-string' should be called with a non-nil > LITERAL argument in this case. Maybe someone (neilson runs and hides!) should write a tool that allows construction of C++11-style raw string literals that would auto-transmogrify into the backslash mess that elisp requires.