now able to return the current source-code block's body with noweb references expanded

  new function is `org-babel-expand-noweb-references'

lisp/org-babel-tangle.el

@@ -49,7 +49,6 @@ file using `load-file'."
                               (sixth (file-attributes file))))))
     (let* ((base-name (file-name-sans-extension file))
            (exported-file (concat base-name ".el")))
-      ;; (message "building %s" exported-file) ;; debugging
       ;; tangle if the org-mode file is newer than the elisp file
       (unless (and (file-exists-p exported-file) (> (age file) (age exported-file)))
         (org-babel-tangle-file file base-name "emacs-lisp"))
@@ -74,7 +73,7 @@ exported source code blocks by language."
   (save-excursion
     (let ((block-counter 0)
           path-collector)
-      (mapc ;; for every language create a file
+      (mapc ;; map over all languages
        (lambda (by-lang)
          (let* ((lang (car by-lang))
                 (specs (cdr by-lang))
@@ -165,5 +164,48 @@ form
       (insert-comment (format "%s ends here" source-name))
       (insert "\n"))))
 
+(defun org-babel-expand-noweb-references (&optional info parent-buffer)
+  "This function expands Noweb style references in the body of
+the current source-code block.  The reference must be inside of a
+comment or it will be skipped.  For example the following
+reference would be replaced with the body of the source-code
+block named 'example-block' (assuming the '#' character starts a
+comment) .
+
+# <<example-block>>
+
+This function must be called from inside of the buffer containing
+the source-code block which holds BODY."
+  (interactive)
+  (let* ((parent-buffer (or parent-buffer (current-buffer)))
+         (info (or info (org-babel-get-src-block-info)))
+         (lang (first info))
+         (body (second info))
+         (new-body "") index source-name)
+    (with-temp-buffer
+      (insert body) (goto-char (point-min))
+      (funcall (intern (concat lang "-mode")))
+      (setq index (point))
+      (while (and (re-search-forward "<<\\(.+\\)>>" nil t)
+                  (save-match-data (comment-beginning)))
+        (save-match-data (setf source-name (match-string 1)))
+        ;; add interval to new-body
+        (goto-char (match-end 0))
+        (setq new-body (concat new-body (buffer-substring index (point))))
+        (setq index (point))
+        ;; if found, add body of referenced source-block
+        (setq new-body
+              (concat new-body
+                      (save-excursion
+                        (set-buffer parent-buffer)
+                        (let ((point (org-babel-find-named-block source-name)))
+                          (if point
+                              (save-excursion
+                                (goto-char point)
+                                (concat "\n" (second (org-babel-get-src-block-info))))
+                            ""))))))
+      (setq new-body (concat new-body (buffer-substring index (point-max)))))
+    new-body))
+
 (provide 'org-babel-tangle)
 ;;; org-babel-tangle.el ends here

org-babel.org

@@ -208,10 +208,10 @@ would then be [[#sandbox][the sandbox]].
 
   
 * Tasks [39/61]
-** TODO new reference syntax *inside* source code blocks
+** STARTED 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
+of Noweb.  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.
@@ -227,14 +227,14 @@ puts "---------------------------footer---------------------------"
 #+end_src
 
 #+srcname: ems-ruby-print-message
-#+begin_src ruby :file ruby-nuweb.rb
+#+begin_src ruby :file ruby-noweb.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
+being generated at =ruby-noweb.rb= with the following contents
 
 : puts "---------------------------header---------------------------"
 : puts "                            Ruby                            "
@@ -1179,7 +1179,7 @@ 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)
+literate programming along the Noweb model)
 
 I'm not sure how we can devise a single simple tangling system that
 naturally fits both of these use cases.

test-tangle.org

@@ -19,12 +19,18 @@ more text
   end
 #+end_src
 
-
 #+srcname: first-ruby-block
 #+begin_src ruby :session special :tangle trivial-symbol
 :block_the_first
 #+end_src
 
+#+srcname: ruby-with-noweb-references
+#+begin_src ruby 
+  # <<ruby-no-session>>
+  hello()
+#+end_src
+
+
 
 ** Some subsection