I believe the two approaches you describe are less different than you think. Notice that local-set-key does in fact evaluate (define-key map key command) where map is the value of (current-local-map), which is typically set by the major mode. So although they could be doing different things; most of the time the only real difference … Read more
Start with Emacs Lisp (given that you seem to have already started customizing your emacs) – it seems to be more immediately useful for you. Do keep in mind that there is quite a bit of difference between Emacs Lisp (there is a lot of buffer management stuff, especially in the code you’re likely to … Read more
You’ll need to provide more information to be sure. Try setting (setq debug-on-error t) which will give you a stack trace showing what function is complaining about the string being nil. My guess is that buffer-file-name is returning nil, and that’s where the problem lies (not all buffers have file names). Check out the debugging … Read more
Not minutes after asking the question I figured it out by copy+pasting code. However I have no clue how it works. (global-set-key (kbd “M-<up>”) (lambda () (interactive) (move-line -1)))
If you (require ‘cl) then you can use the Common Lisp function reduce. Pass the keyword argument :from-end t for foldr. ELISP> (reduce #’list ‘(1 2 3 4)) (((1 2) 3) 4) ELISP> (reduce #’list ‘(1 2 3 4) :from-end t) (1 (2 (3 4)))
To track the problem down, you can try this: (setq max-specpdl-size 5) ; default is 1000, reduce the backtrace level (setq debug-on-error t) ; now you should get a backtrace C-h a ; in speedbar You should get a backtrace upon the error, and at that point, you can track down the offending routine. I’d … Read more
Found another solution with lexical-let (defun foo (n) (lexical-let ((n n)) #'(lambda() n))) (funcall (foo 10)) ;; => 10
tripleee’s answer is a handy example of error handling, but unnecessary in this instance. (when (require ‘some-library nil ‘noerror) do-things) That ‘noerror can be any non-nil value, but of course it’s more descriptive this way. I often see :noerror used as well, but I’ve no idea if there’s any particular advantage to using a keyword … Read more
The Emacs commands backward-page and forward-page (C-x [ and C-x ]), among others, take advantage of ^Ls placed in the code as separators. The habit did not propagate much to languages other than Emacs-lisp, but most languages treat ^L as a blank, so you can use these separators in your favorite language if you like … Read more
New answer: While my original answer is still valid, I now use the method suggested by Jordon. use-package is a fantastic tool for tidy Emacs configurations. In fact, I was already using it for clean package loading when I wrote my original answer. At that time, I neglected to read all the way to the … Read more