keypeat.el

;;; keypeat.el -*- lexical-binding: t; -*-

(defvar ++keypeat-last-keys nil)

(defun ++keypeat-save-h ()
  (setq ++keypeat-last-keys (this-command-keys)))

(add-hook 'post-command-hook #'++keypeat-save-h)

(defun ++keypeat-push-prefix (keyseq)
  (setq unread-command-events
        (mapcar (lambda (k) `(t . ,k))
                (listify-key-sequence (seq-subseq keyseq 0 -1)))))

(defun ++keypeat-repeat ()
  (unless (memq this-command '(++keypeat/next ++keypeat/last))
    (if (not this-command)
        (remove-hook 'post-command-hook #'++keypeat-repeat)
      (++keypeat-push-prefix (this-command-keys)))))

(defun ++keypeat/next ()
  (interactive)
  (add-hook 'post-command-hook #'++keypeat-repeat))

(defun ++keypeat/last ()
  (interactive)
  (++keypeat/next)
  (++keypeat-push-prefix ++keypeat-last-keys))