Zmacs' kill-backward-up-list

[Emilio Lopes]

This Zmacs function seems to be missing in GNU Emacs. I find
it very useful when programming Lisp/Scheme.


;; the Zmacs function `kill-backward-up-list':
(defun kill-backward-up-list (&optional arg)
  "Kill the form containing the current sexp, leaving the sexp itself.
A prefix argument ARG causes the relevant number of surrounding
forms to be removed."
  (interactive "*p")
  (let ((current-sexp (thing-at-point 'sexp)))
    (if current-sexp
        (save-excursion
          (backward-up-list arg)
          (kill-sexp)
          (insert current-sexp))
      (error "Not at a sexp"))))