bug#32731: 26.1.50; Ibuffer filter by mode: Handle >1 mode names

[Tino Calancha]

On Thu, 13 Sep 2018, Noam Postavsky wrote:

> On 13 September 2018 at 14:19, Tino Calancha <tino.calancha@gmail.com> wrote:
>
> > +;;;###autoload
> > +(defun ibuffer-filter-by-used-modes(modes)
> > +  "Limit current view to buffers with major mode in MODES.
> > +MODES is a list of mode names (symbols).
> > +When called interactively, accept the mode names separated by commas."
> > +  (interactive
> > +   (let* ((buf (ibuffer-current-buffer))
> > +          (default (if (and buf (buffer-live-p buf))
> > +                       (symbol-name (buffer-local-value
> > +                                     'major-mode buf)))))
> > +     (list
> > +      (mapcar #'intern
> > +              (split-string
> > +               (completing-read
> > +                (if default
> > +                    (format "Filter by major mode (default %s): " default)
> > +                  "Filter by major mode: ")
> > +                (ibuffer-list-buffer-modes)
> > +                nil nil nil nil default)
> > +               "\\s-*,\\s-*" t)))))
>
> This will use completion only for the first mode, right?
Yeah, that's right.
> Perhaps completing-read-multiple would make more sense here.
Hummmm, it sounds like a good idea.  I will look on it.

> > +  (setq modes (delete-dups modes))
> > +  (mapc #'ibuffer-filter-by-used-mode modes)
> > +  (let ((nb_modes (length modes)))
> > +    (when (>= nb_modes 2)
> > +      (cl-loop repeat (- nb_modes 2) do (ibuffer-or-filter))
> > +      (message nil)
>
> What's this `message' call for?
To clean the minibuffer after the second filter fails;
before you do the composition, you have an implicit AND, so
you are requiring:
(and (eq major-mode mode1-mode) (eq major-mode mode2-mode))
;; This fails
;; after  `ibuffer-or-filter' previous line is changed to:
(or (eq major-mode mode1-mode) (eq major-mode mode2-mode))

> > +      (ibuffer-or-filter))))
>
> Maybe it's simpler to construct the filter directly? As in:
>
>  (push `(or ,@(mapcar (lambda (m) `(used-mode . ,m)) modes))
>        ibuffer-filtering-qualifiers)
>  (ibuffer-update nil t)
Right, much more elegant.  Thank you!
I will update the patch accordingly