Alieniloquent

One of the things that I require from an editor is decent syntax highlighting. Emacs provides me that, and it also provides me with awesome indentation (I’ve grown addicted to hitting TAB and having my text just go to the right place regardless of where my cursor is). Emacs has a mode for every occasion and typically will load the right one based on the name of the file or its content. Recently, mine stopped doing that.

At first it was annoying. I’d open a LaTeX file and it wouldn’t change to latex-mode, or I’d open a C file and it wouldn’t go into c-mode, and worst of all, I’d load Emacs lisp files and they wouldn’t load in emacs-lisp-mode. I would just switch the mode by hand, but my patience could only last for so long.

Yesterday I finally took the time to find the trouble, shoot it, and replace it with better code. In my .emacs I had this:

(setq auto-mode-alist
      (append
       '(("\\.dtd$" . xml-mode)
         ("\\.xml$" . xml-mode)
         ("\\.yml$" . conf-mode)
         ("bash_profile$" . sh-mode)
         ("bashrc$" . sh-mode))
       auto-mode-alist))

I’ve seen that same code all over the internet, and it used to work just fine. But for some reason, now it does something to my auto-mode-alist and makes Emacs hate it for some reason. So I do some research. The recommended way to put stuff in an alist like that is ADD-TO-LIST.

So the above code becomes this:

(mapcar (lambda (mapping) (add-to-list 'auto-mode-alist mapping))
        '(("\\.dtd$" . xml-mode)
          ("\\.xml$" . xml-mode)
          ("\\.yml$" . conf-mode)
          ("bash_profile$" . sh-mode)
          ("bashrc$" . sh-mode)))

Putting that code in fixed my problems, and now all of my modes load correctly.