         ;; TODO: Avoid adding trailing caused by org-indent-line.
         (delete-trailing-whitespace)))))
 
-(defvar ar/helm-source-my-todos `((name . "TODOS")
-                                  (candidates . ,(ar/todos-helm-candidates))
-                                  (action . (lambda (candidate)
-                                              (cond ((plist-get candidate :marker)
-                                                     (org-goto-marker-or-bmk (plist-get candidate :marker)))
-                                                    ((plist-get candidate :url)
-                                                     (org-open-link-from-string (plist-get candidate
-                                                                                           :url))))))))
+(defvar ar/helm-source-my-todos
+  '((name . "TODOS")
+    (candidates . ar/todos-helm-candidates)
+    (action . (lambda (candidate)
+                (cond ((plist-get candidate
+                                  :marker)
+                       (org-goto-marker-or-bmk (plist-get candidate
+                                                          :marker)))
+                      ((plist-get candidate :url)
+                       (org-open-link-from-string (plist-get candidate
+                                                             :url))))))))
+
 (defun ar/helm-todos ()
   "Current TODOS."
   (interactive)

  ("I" (ar/hot-expand "<I"))
  ("H" (ar/hot-expand "<H"))
  ("A" (ar/hot-expand "<A"))
  ("<" self-insert-command "ins")
  ("o" nil "quit"))


  "Create an org CUSTOM_ID from a TITLE."
  (replace-regexp-in-string " " "-" (downcase title)))

(defun ar/string-match-p (regex string)
  "Return t if REGEX matches STRING. nil otherwise."
  (if (string-match regex string) t nil))

(defun ar/string-numeric-p (string)
  "Return t if STRING is an unsigned integer.  nil otherwise."
  (ar/string-match-p "\\`[[:digit:]]+\\'" string))

(defun ar/string-alpha-numeric-p (string)
  "Return t if STRING is alphanumeric.  nil otherwise."
  (ar/string-match-p "\\`[[:alnum:]]+\\'" string))

(defun ar/numeric-clipboard-or-prompt (prompt)
  "Return an integer from clipboard or PROMPT."
  (let* ((clipboard (current-kill 0))
         (number (if (ar/string-numeric-p clipboard)
                     clipboard
                   (read-string (format "%s: "
                                        prompt)))))
    number))

(defun ar/alpha-numeric-clipboard-or-prompt (prompt)
  "Return an alphanumeric string from clipboard or PROMPT."
  (let* ((clipboard (current-kill 0))
         (alpha-num-string (if (ar/string-alpha-numeric-p clipboard)
                     clipboard
                   (read-string (format "%s: "
                                        prompt)))))
    alpha-num-string))

(defun ar/org-insert-prefixed-link (prefix prompt)
  "Insert a link with PREFIX and PROMPT if not found in clipboard."
  (interactive)
  (let* ((clipboard (current-kill 0))
         (cl-number (if (ar/string-numeric-p clipboard)
                        clipboard
                      (read-string (format "%s: "
                                           prompt))))
