Simplify and speed up update-buffer-list

eyebrowse.el

@@ -185,6 +185,12 @@ If t, ask for confirmation."
   :type 'boolean
   :group 'eyebrowse)
 
+(defcustom eyebrowse-buffer-list-count 20
+  "How many buffers to keep in the recent list.
+Large numbers slow down switching."
+  :type 'integer
+  :group 'eyebrowse)
+
 (defvar eyebrowse-mode-prefix-map
   (let ((prefix-map (make-sparse-keymap)))
     (define-key prefix-map (kbd "<") 'eyebrowse-prev-window-config)
@@ -327,20 +333,10 @@ If a buffer name equal to OLD is found, it is replaced with NEW."
 (defun update-buffer-list (new-list)
   "Set buffers in NEW-LIST to be the most recently used, in order."
   (when new-list
-    (let (firstbuf buf)
+    (dolist (b (reverse new-list))
-      (while new-list
+      (when (and (buffer-live-p b)
-        (setq buf (car new-list))
+                 (not (minibufferp b)))
-        (when (stringp buf)
+        (switch-to-buffer b)))))
-          (setq buf (get-buffer buf)))
-        (when (buffer-live-p buf)
-          (bury-buffer buf)
-          (unless firstbuf
-            (setq firstbuf buf)))
-        (setq new-list (cdr new-list)))
-      (setq new-list (buffer-list))
-      (while (not (eq (car new-list) firstbuf))
-        (bury-buffer (car new-list))
-        (setq new-list (cdr new-list))))))
 
 (defun eyebrowse--load-window-config (slot)
   "Restore the window config from SLOT."
@@ -358,7 +354,7 @@ If a buffer name equal to OLD is found, it is replaced with NEW."
       (eyebrowse--fixup-window-config window-config)
       (window-state-put window-config (frame-root-window) 'safe)
       (when buffer-list
-        (update-buffer-list buffer-list)))))
+        (update-buffer-list (take eyebrowse-buffer-list-count buffer-list))))))
 
 (defun eyebrowse--string-to-number (x)
   "Version of `string-to-number' that returns nil if not a number."