added tasks for implementing nuweb-style literate programming

TODO new reference syntax *inside* source code blocks
TODO re-work tangling system

org-babel.org

@@ -207,7 +207,50 @@ would then be [[#sandbox][the sandbox]].
 #+end_src
 
   
-* Tasks [38/59]
+* Tasks [38/61]
+** TODO new reference syntax *inside* source code blocks
+This is from an email discussion on the org-mode mailing list with
+Sébastien.  The goal here is to mimic the source-block reference style
+of Nuweb.  Upon export and/or tangle these references could be
+replaced with the actual body of the referenced source-code block.
+
+See the following for an example.
+
+#+srcname: ems-ruby-print-header
+#+begin_src ruby 
+puts "---------------------------header---------------------------"
+#+end_src
+
+#+srcname: emacs-ruby-print-footer
+#+begin_src ruby 
+puts "---------------------------footer---------------------------"
+#+end_src
+
+#+srcname: ems-ruby-print-message
+#+begin_src ruby :file ruby-nuweb.rb
+  # <<ems-ruby-print-header>>
+  puts "                            Ruby                            "
+  # <<ems-ruby-print-footer>>
+#+end_src
+
+Upon export the previous source-code block would result in a file
+being generated at =ruby-nuweb.rb= with the following contents
+
+: puts "---------------------------header---------------------------"
+: puts "                            Ruby                            "
+: puts "---------------------------footer---------------------------"
+
+** TODO re-work tangling system
+Sometimes when tangling a file (e.g. when extracting elisp from a
+org-mode file) we want to get nearly every source-code block.
+
+Sometimes we want to only extract those source-code blocks which
+reference a indicate that they should be extracted (e.g. traditional
+literate programming along the Nuweb model)
+
+I'm not sure how we can devise a single simple tangling system that
+naturally fits both of these use cases.
+
 ** PROPOSED raise elisp error when source-blocks return errors
 Not sure how/if this would work, but it may be desirable.