emacs implementaion of https://github.com/rhysd/accelerated-jk

accelerated-move.el

(defvar accelerated-move:buffer nil)
(defvar accelerated-move:count 0)
(defvar accelerated-move:point (make-hash-table))
(defvar accelerated-move:table '(7 12 17 21 24 26 28 30))

(defun accelerated-move:previous (&optional arg try-vscroll)
  (interactive "^p\np")
  (accelerated-move:do 'previous-line "previous" arg try-vscroll))

(defun accelerated-move:next (&optional arg try-vscroll)
  (interactive "^p\np")
  (accelerated-move:do 'next-line "next" arg try-vscroll))

(defun accelerated-move:do (original name arg try-vscroll)
  (if (= arg 1)
      (if (and (eq (current-buffer) accelerated-move:buffer)
               (eq (point) (gethash name accelerated-move:point)))
          (setq arg (accelerated-move:calc_acceleration_step accelerated-move:table accelerated-move:count 1))
        (progn
          (setq accelerated-move:count 0)
          (setq arg 1)))
    (setq accelerated-move:count 0))
  (funcall original arg try-vscroll)
  (setq accelerated-move:buffer (current-buffer))
  (puthash name (point) accelerated-move:point)
  (setq accelerated-move:count (1+ accelerated-move:count)))

(global-set-key (kbd "C-p") 'accelerated-move:previous)
(global-set-key (kbd "C-n") 'accelerated-move:next)

(defun accelerated-move:calc_acceleration_step (table count step)
  (cond ((null table) step)
        ((< count (car table)) step)
        (t (accelerated-move:calc_acceleration_step (cdr table) count (1+ step)))))