Ibuffer filter by modes: Accept several mode names

Extend all mode filters so that they handle >1 mode.
For instance, if the users want to filter all buffers in
C or C++ mode, then they can call the filter interactively
with input: 'c-mode,c++-mode' (Bug#32731).

* lisp/ibuf-macs.el(define-ibuffer-filter): Add key :accept-list.
If the value of this key is non-nil, then the filter accepts
either a single qualifier or a list of them; in the latter case,
the resultant filter is the `or' composition of the individual ones.

* lisp/ibuf-ext.el (ibuffer-filter-by-used-mode)
(ibuffer-filter-by-mode, ibuffer-filter-by-derived-mode)
Set :accept-list value non-nil.
Interactively, accept a comma separated list of mode names.

* etc/NEWS(Ibuffer): Announce this change.

Co-authored-by: Noam Postavsky <npostavs@gmail.com>

3 files changed, 73 insertions, 42 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 474af167e83..7e7de165ec1 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -62,6 +62,11 @@ to reduce differences between developer and production builds.
 ** Ibuffer
 
 ---
+*** All mode filters can now accept a list of symbols.
+This means you can now easily filter several major modes, as well
+as a single mode.
+
+---
 *** New toggle 'ibuffer-do-toggle-lock', bound to 'L'.
 
 ** Gnus
diff --git a/lisp/ibuf-ext.el b/lisp/ibuf-ext.el
index d9949d28352..32ec91db970 100644
--- a/lisp/ibuf-ext.el
+++ b/lisp/ibuf-ext.el
@@ -1228,28 +1228,33 @@ If INCLUDE-PARENTS is non-nil then include parent modes."
 
 ;;;###autoload (autoload 'ibuffer-filter-by-mode "ibuf-ext")
 (define-ibuffer-filter mode
-  "Limit current view to buffers with major mode QUALIFIER."
+    "Limit current view to buffers with major mode(s) specified by QUALIFIER.
+QUALIFIER is the mode name as a symbol or a list of symbols.
+Called interactively, accept a comma separated list of mode names."
   (:description "major mode"
    :reader
    (let* ((buf (ibuffer-current-buffer))
           (default (if (and buf (buffer-live-p buf))
                        (symbol-name (buffer-local-value
                                      'major-mode buf)))))
-     (intern
-      (completing-read
+     (mapcar #'intern
+      (completing-read-multiple
        (if default
            (format "Filter by major mode (default %s): " default)
          "Filter by major mode: ")
        obarray
-       #'(lambda (e)
-           (string-match "-mode\\'" (symbol-name e)))
-       t nil nil default))))
+       (lambda (e)
+           (string-match "-mode\\'" (if (symbolp e) (symbol-name e) e)))
+       t nil nil default)))
+   :accept-list t)
   (eq qualifier (buffer-local-value 'major-mode buf)))
 
 ;;;###autoload (autoload 'ibuffer-filter-by-used-mode "ibuf-ext")
 (define-ibuffer-filter used-mode
-  "Limit current view to buffers with major mode QUALIFIER.
-Called interactively, this function allows selection of modes
+    "Limit current view to buffers with major mode(s) specified by QUALIFIER.
+QUALIFIER is the mode name as a symbol or a list of symbols.
+
+Called interactively, accept a comma separated list of mode names
 currently used by buffers."
   (:description "major mode in use"
    :reader
@@ -1257,23 +1262,29 @@ currently used by buffers."
           (default (if (and buf (buffer-live-p buf))
                        (symbol-name (buffer-local-value
                                      'major-mode buf)))))
-     (intern
-      (completing-read
+     (mapcar #'intern
+      (completing-read-multiple
        (if default
            (format "Filter by major mode (default %s): " default)
          "Filter by major mode: ")
-       (ibuffer-list-buffer-modes) nil t nil nil default))))
+       (ibuffer-list-buffer-modes) nil t nil nil default)))
+   :accept-list t)
   (eq qualifier (buffer-local-value 'major-mode buf)))
 
 ;;;###autoload (autoload 'ibuffer-filter-by-derived-mode "ibuf-ext")
 (define-ibuffer-filter derived-mode
-    "Limit current view to buffers whose major mode inherits from QUALIFIER."
+    "Limit current view to buffers with major mode(s) specified by QUALIFIER.
+QUALIFIER is the mode name as a symbol or a list of symbols.
+ Restrict the view to buffers whose major mode derivates
+ from modes specified by QUALIFIER.
+Called interactively, accept a comma separated list of mode names."
   (:description "derived mode"
-                :reader
-                (intern
-                 (completing-read "Filter by derived mode: "
-                                  (ibuffer-list-buffer-modes t)
-                                  nil t)))
+        :reader
+        (mapcar #'intern
+         (completing-read-multiple "Filter by derived mode: "
+                       (ibuffer-list-buffer-modes t)
+                       nil t))
+        :accept-list t)
   (with-current-buffer buf (derived-mode-p qualifier)))
 
 ;;;###autoload (autoload 'ibuffer-filter-by-name "ibuf-ext")
diff --git a/lisp/ibuf-macs.el b/lisp/ibuf-macs.el
index 6a70a8341a2..72a35a53315 100644
--- a/lisp/ibuf-macs.el
+++ b/lisp/ibuf-macs.el
@@ -280,14 +280,18 @@ buffer object.
 
 ;;;###autoload
 (cl-defmacro define-ibuffer-filter (name documentation
-                                       (&key
-                                        reader
-                                        description)
-                                       &rest body)
+                                         (&key
+                                          reader
+                                          description
+                                          accept-list)
+                                         &rest body)
   "Define a filter named NAME.
 DOCUMENTATION is the documentation of the function.
 READER is a form which should read a qualifier from the user.
 DESCRIPTION is a short string describing the filter.
+ACCEPT-LIST is a boolean; if non-nil, the filter accepts either
+a single condition or a list of them; in the latter
+case the filter is the `or' composition of the conditions.
 
 BODY should contain forms which will be evaluated to test whether or
 not a particular buffer should be displayed or not.  The forms in BODY
@@ -296,30 +300,41 @@ bound to the current value of the filter.
 
 \(fn NAME DOCUMENTATION (&key READER DESCRIPTION) &rest BODY)"
   (declare (indent 2) (doc-string 2))
-  (let ((fn-name (intern (concat "ibuffer-filter-by-" (symbol-name name)))))
+  (let ((fn-name (intern (concat "ibuffer-filter-by-" (symbol-name name))))
+        (filter (make-symbol "ibuffer-filter"))
+        (qualifier-str (make-symbol "ibuffer-qualifier-str")))
     `(progn
        (defun ,fn-name (qualifier)
-         ,(or documentation "This filter is not documented.")
-         (interactive (list ,reader))
-         (if (null (ibuffer-push-filter (cons ',name qualifier)))
-             (message "%s"
-                      (format ,(concat (format "Filter by %s already applied: " description)
-                                       " %s")
-                              qualifier))
-           (message "%s"
-                    (format ,(concat (format "Filter by %s added: " description)
-                                     " %s")
-                            qualifier))
-           (ibuffer-update nil t)))
+     ,(or documentation "This filter is not documented.")
+     (interactive (list ,reader))
+     (let ((,filter (cons ',name qualifier))
+           (,qualifier-str qualifier))
+       ,(when accept-list
+          `(progn
+         (unless (listp qualifier) (setq qualifier (list qualifier)))
+         ;; Reject equivalent filters: (or f1 f2) is same as (or f2 f1).
+         (setq qualifier (sort (delete-dups qualifier) #'string-lessp))
+         (setq ,filter (cons ',name (car qualifier)))
+         (setq ,qualifier-str
+               (mapconcat (lambda (m) (if (symbolp m) (symbol-name m) m))
+                  qualifier ","))
+         (when (cdr qualifier) ; Compose individual filters with `or'.
+           (setq ,filter `(or ,@(mapcar (lambda (m) (cons ',name m)) qualifier))))))
+       (if (null (ibuffer-push-filter ,filter))
+           (message ,(format "Filter by %s already applied:  %%s" description)
+                ,qualifier-str)
+         (message ,(format "Filter by %s added:  %%s" description)
+              ,qualifier-str)
+         (ibuffer-update nil t))))
        (push (list ',name ,description
-                   (lambda (buf qualifier)
-                     (condition-case nil
-                         (progn ,@body)
-                       (error (ibuffer-pop-filter)
-                              (when (eq ',name 'predicate)
-                                (error "Wrong filter predicate: %S"
-                                       qualifier))))))
-             ibuffer-filtering-alist)
+           (lambda (buf qualifier)
+                  (condition-case nil
+                      (progn ,@body)
+                    (error (ibuffer-pop-filter)
+                           (when (eq ',name 'predicate)
+                             (error "Wrong filter predicate: %S"
+                                    qualifier))))))
+         ibuffer-filtering-alist)
        :autoload-end)))
 
 (provide 'ibuf-macs)