A tool for creating source code files from example and src blocks in org files

["Eric H. Neilsen, Jr." <neilsen@fnal.gov>]

Hi,

First, thank you Carsten and others, for putting this thing together; 
org-mode is the most useful tool I've run across in a long time.

I recently put together a few commands to create source code files from 
SRC and EXAMPLE blocks in org-mode files. The original idea is to be 
able to compile examples in my notes without needing to merge them into 
a separate source file by hand. As I was writing it I realized this is 
exactly the same tool one needs to turn org-mode into a literate 
programming tool (see http://www.literateprogramming.com/ ), so I 
adopted some of the nomenclature. (I tried literate programming a few 
years ago, and gave up in frustration with the tools. I am tempted to 
try again with org-mode.)

The two user level commands are org-tangle and org-untangle, best 
explained through example. Running org-tangle in a buffer that looks 
like this:

---------------------- begin /tmp/test.org ---------------------------
* Some file

Some text here

#+CHUNK file1.sh 1
#+BEGIN_SRC bash
echo "line 1"
echo "line 2"
#+END_SRC

more text

** Some subsection

#+CHUNK file1.sh 2
#+BEGIN_SRC bash
echo "line 5"
echo "line 6"
#+END_SRC

blah blah blah

#+CHUNK README.txt 1
#+BEGIN_EXAMPLE
text line 1
text line 2
text line 3
#+END_EXAMPLE

foo foo bar baz

#+CHUNK file1.sh 1.5
#+BEGIN_SRC bash
echo "line 3"
echo "line 4"
#+END_SRC
-------------- end /tmp/test.org ----------------

results in the creation of these two files, opened in emacs buffers:

------------- begin /tmp/file1.sh ----------------
#      ORGCHUNK /tmp/test.org  1
echo "line 1"
echo "line 2"
#      ORGCHUNK /tmp/test.org  1.5
echo "line 3"
echo "line 4"
#      ORGCHUNK /tmp/test.org  2
echo "line 5"
echo "line 6"
------------- end /tmp/file1.sh ---------------------

and

------------ begin /tmp/README.txt -------------
text line 1
text line 2
text line 3
------------ end /tmp/README.txt ---------------

If you then edit file1.sh and run org-untangle in the buffer, changes to 
it will overwrite the literal blocks in the org-mode file from whence 
they came.

Is there any interest in this? My organization's rules for releasing 
code to open source projects are being revised, but I am likely to be 
able to do so under a BSD-like license. If there is interest, I will 
push to try and figure out how to do this, and maybe even see if I can 
do the assignment of copyright stuff needed for it to get under the main 
umbrella (although I am not optimistic).

(If anyone feels like rewriting it, that would be even better; aside 
from a fairly straightforward .emacs, this is my first ever lisp code, 
so it is likely to need cleaning and refactoring.)

    -Eric

-- 
Eric H. Neilsen, Jr.
http://home.fnal.gov/~neilsen