Allow language names where the major mode name seems unrelated to the language

Eric Schulte writes:

> Attached is a small patch for a small issue.
>
> Sometimes a language uses a major mode which can't be guessed
> from it's name.  This patch introduces the `org-src-lang-modes'
> variable which can be used to map language names to major modes
> when this is the case.  This is used when editing a source-code
> block, or when exporting fontified source-code with htmlize.
>
> So far the only instance of this that I know of is ocaml and
> tuareg-mode, so that's the only thing that `org-src-lang-modes'
> is pre-populated with.  Maybe there are other instances as well?

lisp/ChangeLog

@@ -1,5 +1,11 @@
 2009-08-23  Carsten Dominik  <carsten.dominik@gmail.com>
 
+	* org-exp.el (org-export-format-source-code-or-example): Translate
+	language.
+
+	* org-src.el (org-src-lang-modes): New variable
+	(org-edit-src-code): Translate language.
+
 	* org-exp.el (org-export-format-source-code-or-example): Deal wit
 	the new structure of the `org-export-latex-listings-langs'
 	variable.

lisp/org-exp.el

@@ -2278,7 +2278,15 @@ INDENT was the original indentation of the block."
 		   "htmlize.el 1.34 or later is needed for source code formatting")))
 
 	      (if lang
-		  (let* ((mode (and lang (intern (concat lang "-mode"))))
+		  (let* ((lang-m (when lang
+                                   (or (cdr (assoc lang org-src-lang-modes))
+                                       lang)))
+                         (mode (and lang-m (intern
+					    (concat
+					     (if (symbolp lang-m)
+						 (symbol-name lang-m)
+					       lang-m)
+					     "-mode"))))
 			 (org-inhibit-startup t)
 			 (org-startup-folded nil))
 		    (setq rtn

lisp/org-src.el

@@ -109,6 +109,21 @@ You may want to use this hook for example to turn off `outline-minor-mode'
 or similar things which you want to have when editing a source code file,
 but which mess up the display of a snippet in Org exported files.")
 
+(defcustom org-src-lang-modes
+  '("ocaml" . tuareg)
+  "Alist mapping languages to their major mode.
+The key is the language name, the value is the string that should
+be inserted as the name of the major mode.  For many languages this is
+simple, but for language where this is not the case, this variable
+provides a way to simplify things on the user side.
+For example, there is no ocaml-mode in Emacs, but the mode to use is
+`tuareg-mode'."
+  :group 'org-edit-structure
+  :type '(repeat
+	  (cons
+	   (string "Language name")
+	   (symbol "Major mode"))))
+
 ;;; Editing source examples
 
 (defvar org-src-mode-map (make-sparse-keymap))
@@ -151,7 +166,9 @@ the edited version."
       (setq beg (move-marker beg (nth 0 info))
 	    end (move-marker end (nth 1 info))
 	    code (buffer-substring-no-properties beg end)
-	    lang (nth 2 info)
+	    lang (or (cdr (assoc (nth 2 info) org-src-lang-modes))
+                     (nth 2 info))
+	    lang (if (symbolp lang) (symbol-name lang) lang)
 	    single (nth 3 info)
 	    lfmt (nth 4 info)
 	    nindent (nth 5 info)