From fc831dafd081ebeffc9d98c2a35597bef2a0d34a Mon Sep 17 00:00:00 2001 From: Kévin Le Gouguec Date: Fri, 24 Jun 2022 08:21:22 +0200 Subject: Add an Elisp "cheatsheet" --- guides/emacs/elisp-demos.org | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 guides/emacs/elisp-demos.org (limited to 'guides/emacs') diff --git a/guides/emacs/elisp-demos.org b/guides/emacs/elisp-demos.org new file mode 100644 index 0000000..029f5be --- /dev/null +++ b/guides/emacs/elisp-demos.org @@ -0,0 +1,28 @@ +Some terse "context-free" Emacs Lisp snippets that hopefully speak for +themselves. + +* The prefix argument +#+begin_src elisp +(defun my/prefix-arg-demo (arg) + (interactive (list current-prefix-arg)) + (insert + (let ((num (prefix-numeric-value arg))) + (format "%s %d %s\n" + arg + num + (cond ((null arg) "N/A") + ((numberp arg) (format "M-%d or C-u %d" arg arg)) + ((equal arg '-) (format "M-- or C-u -")) + ((listp arg) + (if (< num 0) + (format "(M-- or C-u -) C-u × %d" (log (- num) 4)) + (format "C-u × %d" (log num 4))))))))) +#+end_src +#+begin_example +nil 1 N/A +2 2 M-2 or C-u 2 +- -1 M-- or C-u - +(-16) -16 (M-- or C-u -) C-u × 2 +(64) 64 C-u × 3 +#+end_example + -- cgit v1.2.3