Keyword argument support is in the Emacs core these days, along with the rest of the CL library. (require 'cl-lib) (cl-defun foo (&key a b c) (list a b

Keyword argument support is in the Emacs core these days, along with the rest of the CL library. (require 'cl-lib) (cl-defun foo (&key a b c) (list a b c)) (foo :c 3 :b 4 :a 1)