Re: org-babel R, export, and :result value raw

[Nick Dokos <nicholas.dokos@hp.com>]

Christophe Rhodes <csr21@cantab.net> wrote:

> Hi,
> 
> Consider the following org-mode file, assuming that org-babel support
> for emacs lisp and R is active:
> 
> --- begin ---
> #+TITLE: Foo
> 
> #+begin_src emacs-lisp :exports results :results value raw
> "[[file:foo.png]]"
> #+end_src
> 
> #+results:
> [[foo.png]]
> 
> #+begin_src R :exports results :results value raw
> "[[file:bar.png]]"
> #+end_src
> #+results: 
> [[file:bar\.png]]
> ---  end  ---
> 
> The problem is probably obvious from the above, but to be explicit: the
> intent is to generate raw org-mode from the code blocks (this case is
> hugely simplified from my actual application), producing links to images
> which will then be part of the eventual exported document.  For emacs
> lisp, this works fine; for R, the path through files and specifically
> org-babel-import-elisp-from-file / org-babel-string-read causes the
> return value to be misinterpreted, introducing an extra backslash, and
> therefore generating bogus export files.
> 
> (This used to work for my use case in org-mode 7.4, and does not work in
> org-mode 7.6; I looked at HEAD to see if I could identify a fix, but did
> not find one -- I'm sorry if I missed it)
> 

This bisects to the following commit:

--8<---------------cut here---------------start------------->8---
commit b6912331715c7da08927b3636b6721af5f5e0c41
Author: Eric Schulte <schulte.eric@gmail.com>
Date:   Tue Mar 1 10:31:00 2011 -0700

    ob: allow passing elisp vectors through to code blocks
    
    * lisp/ob.el (org-babel-read): Pass elisp vectors through to code
      blocks.

diff --git a/lisp/ob.el b/lisp/ob.el
index ea1c968..b0b5fb6 100644
--- a/lisp/ob.el
+++ b/lisp/ob.el
@@ -1913,16 +1913,15 @@ (defun org-babel-script-escape (str)
 
 (defun org-babel-read (cell &optional inhibit-lisp-eval)
   "Convert the string value of CELL to a number if appropriate.
-Otherwise if cell looks like lisp (meaning it starts with a \"(\"
-or a \"'\") then read it as lisp, otherwise return it unmodified
-as a string.  Optional argument NO-LISP-EVAL inhibits lisp
-evaluation for situations in which is it not appropriate."
+Otherwise if cell looks like lisp (meaning it starts with a
+\"(\", \"'\", \"`\" or a \"[\") then read it as lisp, otherwise
+return it unmodified as a string.  Optional argument NO-LISP-EVAL
+inhibits lisp evaluation for situations in which is it not
+appropriate."
   (if (and (stringp cell) (not (equal cell "")))
       (or (org-babel-number-p cell)
           (if (and (not inhibit-lisp-eval)
-		   (or (equal "(" (substring cell 0 1))
-		       (equal "'" (substring cell 0 1))
-		       (equal "`" (substring cell 0 1))))
+		   (member (substring cell 0 1) '("(" "'" "`" "[")))
               (eval (read cell))
             (progn (set-text-properties 0 (length cell) nil cell) cell)))
     cell))
--8<---------------cut here---------------end--------------->8---

If I revert it, I get the 7.4 behavior.

The problem is that  "[..." looks like a lisp vector to this function.

Nick