sbbs.el

            (unless (memq (get-text-property (point) 'sbbs-thread-nr)
                          spec)
              (add-text-properties
               (point) last '(invisible t intangible t)))
            (setq last (point)))))
      (goto-char (point-min))
      (when spec
        (sbbs--read-jump-to (apply #'min spec)))
      (let ((point (point)))
        (when sbbs-jump-to-link
          (forward-button 1)
          (when (invisible-p (point))
            (goto-char point)))))))

(defun sbbs--insert-link (text link)

                              (sbbs-view-open id range)))
                           ;; other thread
                           ((/= id sbbs--thread-id)
                            (let ((sbbs--board board))
                              (sbbs-view-open id range)))
                           ;; this thread
                           (range (sbbs--limit-to-range range))))))
        (insert-button text 'action func 'sbbs-ref range)))))

(defun sbbs--insert-sxml-par (sxml)
  "Insert paragraph contents SXML at point."
  (dolist (it sxml)
    (cond ((stringp it)
           (insert (propertize it 'face 'variable-pitch)))
          ((eq (car it) 'br)

(defun sbbs-show-pop (&optional n)
  "Show all hidden posts.

A prefix argument N, repeats this N times. If negative or zero,
pop all the way up."
  (interactive "P")
  (let ((n (or n 1)))
    (unless sbbs--limit-stack
      (message "Nothing left to pop"))
    (dotimes (_ (if (> n 0) n (length sbbs--limit-stack)))
      (let ((point (car (pop sbbs--limit-stack))))
        (sbbs--limit-to-range (cdar sbbs--limit-stack) t)
        (when point (goto-char point))))))

(defun sbbs-show-replies ()
  "Show all posts responding to post at point."
  (interactive)
  (let ((nr (get-text-property (point) 'sbbs-thread-nr))
        (point (point)) overlay range)
    (while (setq overlay (next-button point))
      (when (memq nr (overlay-get overlay 'sbbs-ref))
        (push (get-text-property (overlay-start overlay)
                                 'sbbs-thread-nr)
              range))
      (setq point (overlay-end overlay)))
    (if range
        (sbbs--limit-to-range range)
      (message "No posts referencing %d" nr))))

(defun sbbs-view-open (id &optional range)
  "Open thread ID in new buffer."
  (interactive (list (tabulated-list-get-id)))
  (let ((url (sbbs--board-url (format "/%d" id) t))
        (headline (or (and (not (tabulated-list-get-entry))
                           header-line-format)
                      (substring-no-properties

    (define-key map (kbd "<tab>") #'forward-button)
    (define-key map (kbd "<backtab>") #'backward-button)
    (define-key map (kbd "r") #'sbbs-read-reply)
    (define-key map (kbd "n") #'sbbs-read-next)
    (define-key map (kbd "p") #'sbbs-read-previous)
    (define-key map (kbd "a") #'sbbs-show-pop)
    (define-key map (kbd "A") #'sbbs-show-all)
    (define-key map (kbd "f") #'sbbs-show-replies)
    map))

(define-derived-mode sbbs-read-mode special-mode "SchemeBBS Read"
  "Major mode for reading a thread."
  (buffer-disable-undo)
  (visual-line-mode t)
  (setq-local revert-buffer-function #'sbbs--reload-thread))