Toggle Clojure #_ ignore forms in Emacs

clojure-toggle-ignore.el

(defun clojure--toggle-ignore-next-sexp (&optional n)
  "Insert or delete N `#_' ignore macros at the current point.
Point must be directly before a sexp or the #_ characters.
When acting on a top-level form it inserts #_ on a new line
preceding the form."
  (let ((rgx (rx-to-string `(repeat ,(or n 1) (seq "#_" (* (in "\r\n" blank)))))))
    (backward-prefix-chars)
    (skip-chars-backward "#_")
    (cond
     ((looking-at rgx) ;; point is before #_
      (delete-region (point) (match-end 0)))
     ((looking-back rgx) ;; point is after #_
      (delete-region (match-beginning 0) (point)))
     (t
      (dotimes (_ (or  n 1)) (insert "#_"))
      (when (zerop (car (syntax-ppss)))
        (insert "\n"))))))

(defun clojure-toggle-ignore-surrounding-form (&optional arg)
  "Toggle the #_ ignore reader form for the surrounding form at point.
With optional ARG, move up by ARG surrounding forms first.
With universal argument \\[universal-argument], act on the current top level defun. "
  (interactive "P")
  (save-excursion
    (cond
     ;; called with C-u, act on defun
     ((consp arg)
      (beginning-of-defun)
      (clojure--toggle-ignore-next-sexp))
     ;; navigate to start of sexp
     ((not (looking-at-p (rx (or "#_" "(" "[" "{"))))
      ;; guard against moving past top level
      (condition-case nil
          (backward-up-list arg t t)
        (scan-error nil))
      (clojure--toggle-ignore-next-sexp))
     ;; looking at start of sexp
     (t (clojure--toggle-ignore-next-sexp)))))

(defun clojure-toggle-ignore-form (&optional n)
  "Toggle the #_ ignore reader form for the sexp at point.
With numeric argument, toggle N number of #_ forms at the same point.

  e.g. with N = 2:
  |a b c  => #_#_a b c

If a region is selected, the (comment ...) form is used instead
to surround the active region, which is assumed to be balanced."
  (interactive "p")
  (save-excursion
    (if (region-active-p)
        ;; multiple forms selected, use (comment ...) syntax
        (let ((beg (region-beginning)))
          (goto-char (region-end))
          (insert " )\n")
          (goto-char beg)
          (save-excursion (insert "(comment\n"))
          (prog-indent-sexp))
      (skip-chars-forward "[:space:]\r\n")
      (ignore-errors (beginning-of-thing 'symbol))
      (clojure--toggle-ignore-next-sexp n))))

;; spacemacs config:
(spacemacs|forall-clojure-modes m
  (spacemacs/set-leader-keys-for-major-mode m
    "cc" #'clojure-toggle-ignore-surrounding-form
    "cs" #'clojure-toggle-ignore-form))