(require 'navi2ch)

(defvar navi2ch-bm-board-updated-line-regexp "[%+= ]U\\|[%+ ][CV]")
(defvar navi2ch-bm-other-updated-line-regexp " U")

(defun navi2ch-bm-forward-updated-line (&optional n)
  (interactive "p")
  (unless n
    (setq n 1))
  (let ((case-fold-search nil)
        (regexp (concat "^ *[0-9]+ \\("
                        (if (eq major-mode 'navi2ch-board-mode)
                            navi2ch-bm-board-updated-line-regexp
                          navi2ch-bm-other-updated-line-regexp)
                        "\\)"))
        (unit (if (> n 0) 1 -1)))
    (if (> n 0)
        (end-of-line)
      (beginning-of-line))
    (while (and (/= n 0)
                (re-search-forward regexp nil t unit))
      (setq n (- n unit)))
    (beginning-of-line)
    n))

(defun navi2ch-bm-next-updated-line (&optional num)
  (interactive "p")
  (when (/= (navi2ch-bm-forward-updated-line num) 0)
    (message "No more updated articles")))

(defun navi2ch-bm-previous-updated-line (&optional num)
  (interactive "p")
  (when (/= (navi2ch-bm-forward-updated-line (- (or num 1))) 0)
    (message "No more updated articles")))

(define-key navi2ch-bm-mode-map "N" 'navi2ch-bm-next-updated-line)
(define-key navi2ch-bm-mode-map "P" 'navi2ch-bm-previous-updated-line)

(provide 'navi2ch-board-custom)