View and edit the filter stack

[Boruch-Baum]

Hi. I've started toying with your package and really enjoy it. For me, it immediately became important to be able to view and manipulate the filter stack. I wasn't always certain what exactly was on the filter stack, and I wanted to make subtle changes to elements in the middle of the filter stack. What I came up with for my personal use is this:

(use-package occur-x
:hook (occur-mode . turn-on-occur-x-mode)
:config
(defcustom occur-x-view-preference 'pp-eval-expression
  "How to be view the `occur-x' filter stack.
This should be the name of a function that takes a single
argument, symbol `occur-x-filter-ops'. The function 
`refine' from the MELPA package of the same name is a
good option for this. Note that using `refine' will add that
package's ability to edit, re-arrange, and otherwise
directly manipulate items on the filter stack."
  :type 'symbol)

(defun occur-x-view ()
  "View the filter list."
  (interactive)
  (unless (eq major-mode 'occur-mode)
    (user-error "Occur-x-view: Current buffer isn't an occur buffer."))
  (funcall occur-x-view-preference 'occur-x-filter-ops))

(setq occur-x-view-preference 'refine)

:bind (:map occur-x-mode-map ("v" . 'occur-x-view)))

Some version of this capability might benefit some of your other users. Personally, I recommend that you DON'T add the refine package as a dependency because it itself pulls in many dependencies and my coding ethos is to avoid bloat. I did it on my personal Emacs because I had the refine package installed anyway (and I use it a lot).