update emacs config to 21th century

conf-lisp/recentfiles.el

@@ -0,0 +1,61 @@
+;;; *** Recent Files
+
+;; You know the  file you edited yesterday had "kri"  in its name, but
+;; where was it? You don't remember.  But don't worry, recent files is
+;; your friend.  It shows the last  N files you edited  recently.
+;; I use it permanently.
+
+;; see also: ido-mode and smex
+
+(defun tvd-buffer-exists-p (bufname)
+  (not (eq nil (get-file-buffer bufname))))
+
+;; setup
+(use-package recentf
+             :config
+             (require 'cl-lib)
+             (setq recentf-auto-cleanup 'never) ;; avoid stat() on tramp buffers
+             (recentf-mode 1)
+
+             ;; I like to have a longer list reaching deeper into the past
+             (setq recentf-max-menu-items 200
+                   recentf-max-saved-items nil)
+
+             ;; enable IDO completion
+             ;; via [[http://emacsredux.com/blog/2013/04/05/recently-visited-files/][emacsredux]]
+             ;; modified to exclude already visited files
+             (defun recentf-ido-find-file ()
+               "Find a recent file using ido."
+               (interactive)
+               (let ((file (ido-completing-read
+                            "Choose recent file: "
+                            (cl-remove-if 'tvd-buffer-exists-p recentf-list) nil t)))
+                 (when file
+                   (find-file file))))
+
+             (global-set-key (kbd "C-x C-r")         'recentf-ido-find-file)                           ; open recent files, same as M-x rf
+
+             ;; now if I incidentally closed a  buffer, I can re-open it, thanks to
+             ;; recent-files
+             (defun undo-kill-buffer (arg)
+               "Re-open the last buffer killed.  With ARG, re-open the nth buffer."
+               (interactive "p")
+               (let ((recently-killed-list (copy-sequence recentf-list))
+                     (buffer-files-list
+                      (delq nil (mapcar (lambda (buf)
+                                          (when (buffer-file-name buf)
+                                            (expand-file-name (buffer-file-name buf)))) (buffer-list)))))
+                 (mapc
+                  (lambda (buf-file)
+                    (setq recently-killed-list
+                          (delq buf-file recently-killed-list)))
+                  buffer-files-list)
+                 (find-file
+                  (if arg (nth arg recently-killed-list)
+                    (car recently-killed-list)))))
+
+             ;; exclude some auto generated files
+             (setq recentf-exclude (list "ido.last"
+                                         "/elpa/"
+                                         ".el.gz$"
+                                         '(not (file-readable-p)))))