Add commands for toggling #_ ignore forms

Author: yuhan0

clojure-mode.el

@@ -2822,6 +2822,57 @@ Assumes cursor is at beginning of function."
         (clojure--add-arity-reify-internal)))
       (indent-region beg end-marker))))
 
+
+;;; Toggle Ignore forms
+
+(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, insert #_ on a new line
+preceding the form to prevent indentation changes."
+  (let ((rgx (rx-to-string `(repeat ,(or n 1) (seq "#_" (* (in "\r\n" blank)))))))
+    (backward-prefix-chars)
+    (skip-chars-backward "#_ \r\n")
+    (skip-chars-forward " \r\n")
+    (if (looking-at rgx)
+        (delete-region (point) (match-end 0))
+      (dotimes (_ (or  n 1)) (insert-before-markers "#_"))
+      (when (zerop (car (syntax-ppss)))
+        (insert-before-markers "\n")))))
+
+(defun clojure-toggle-ignore (&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"
+  (interactive "p")
+  (save-excursion
+    (ignore-errors
+      (goto-char (or (nth 8 (syntax-ppss)) ;; beginning of string
+                     (beginning-of-thing 'sexp))))
+    (clojure--toggle-ignore-next-sexp 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 \"top-level\" form."
+  (interactive "P")
+  (save-excursion
+    (if (consp arg)
+        (clojure-toggle-ignore-defun)
+      (condition-case nil
+          (backward-up-list arg t t)
+        (scan-error nil)))
+    (clojure--toggle-ignore-next-sexp)))
+
+(defun clojure-toggle-ignore-defun ()
+  "Toggle the #_ ignore reader form for the \"top-level\" form at point."
+  (interactive)
+  (save-excursion
+    (beginning-of-defun)
+    (clojure--toggle-ignore-next-sexp)))
+
 
 ;;; ClojureScript
 (defconst clojurescript-font-lock-keywords