Fix org source block language execution

config.org

@@ -248,13 +248,31 @@
 
    =babel= lets us evaluate Org documents containing source blocks!
    I've left the enabling of this for most languages to the section
-   for that language, but I'll add Emacs Lisp and shell here.
+   for that language, but I'll add Shell and Elisp here.
 
    #+begin_src emacs-lisp
      (org-babel-do-load-languages
       'org-babel-load-languages
       '((emacs-lisp . t)
-        (shell . t)))
+	(shell . t)))
+   #+end_src
+
+   The interface org-babel exposes is a little annoying as later in
+   this config we'll want to preserve the prior value of
+   [[help:org-babel-load-languages][org-babel-load-languages]] when enabling another language. However,
+   ~org-babel-do-load-languages~ /sets the passed symbol to the passed
+   value/ with [[help:set-default][set-default]] before going through the pairs in
+   ~org-babel-load-languages~. Don't ask me why, seems like an
+   obviously bad design. Workaround is to define a function here to
+   use later so at least it won't /look/ ugly.
+
+   #+begin_src emacs-lisp
+     (defun enable-org-babel-lang (lang)
+       "Enable executing source block in the passed language in
+     org-mode. Doesn't affect other enabled languages."
+       (org-babel-do-load-languages
+        'org-babel-load-languages
+        (append org-babel-load-languages `((,lang . t)))))
    #+end_src
 
    By default trying to execute a source block prompts you, which is
@@ -608,13 +626,10 @@
     #+end_src
 
 **** Source blocks
-     To enable execution of CL source blocks in Org mode, add an item
-     to [[help:org-babel-load-languages][org-babel-load-languages]].
+     Enable execution of CL source blocks in Org mode:
 
      #+begin_src emacs-lisp
-       (org-babel-do-load-languages
-        'org-babel-load-languages
-        '((lisp . t)))
+       (enable-org-babel-lang 'lisp)
      #+end_src
 
 *** Paredit
@@ -843,8 +858,7 @@
    diagrams):
 
    #+begin_src emacs-lisp
-     (add-to-list 'org-babel-load-languages
-                  '(mermaid . t))
+     (enable-org-babel-lang 'mermaid)
    #+end_src
 
 * Tool Integrations