anchor.diff:                                    tree))))))
            (insert-content (ps:ps (setf (ps:@ document Body |innerHTML|)
                                         (ps:lisp content)))))
  +    (print content)
       (ffi-buffer-evaluate-javascript-async output-buffer insert-content)
       (set-current-buffer output-buffer)))
   
  
positive.code:          (tree `(:ul ,(htree:map-tree
                         #'(lambda (node)
                             `(:li (:a :href ,(object-string (url (htree:data node)))
                                    ,(let ((title (or (match (title (htree:data node))
                                                        ((guard e (not (str:emptyp e))) e))
                                                      (object-display (url (htree:data node))))))
                                       (if (eq node (htree:current history))
                                           `(:b ,title)
                                           title)))))
                         (htree:root history)
                         :include-root t
                         :collect-function #'(lambda (a b) `(,@a ,(when b `(:ul ,@b)))))))
           (tree-style
                  (cl-css:css
                   '((body
                      :line-height "initial")
                     (* :margin 0
                        :padding 0
                        :list-style "none")
                     ("ul li"
                      :margin-left "15px"
                      :position "relative"
                      :padding-left "5px")
                     ("ul li::before"
                      :content "' '"
                      :position "absolute"
                      :width "1px"
                      :background-color "#000"
                      :top "5px"
                      :bottom "-12px"
                      :left "-10px")
                     ("body > ul > li:first-child::before"
                      :top "12px")
                     ("ul li:not(:first-child):last-child::before"
                      :display "none")
                     ("ul li:only-child::before"
                      :display "list-item"
                      :content "' '"
                      :position "absolute"
                      :width "1px"
                      :background-color "#000"
                      :top "5px"
                      :bottom "7px"
                      :height "7px"
                      :left "-10px")
                     ("ul li::after"
                      :content "' '"
                      :position "absolute"
                      :left "-10px"
                      :width "10px"
                      :height "1px"
                      :background-color "#000"
                      :top "12px"))))
           (content (markup:markup
                     (:body (:h1 "History")
                            (:style (style output-buffer))
  
negative.code:     (ffi-buffer-evaluate-javascript-async output-buffer insert-content)
      (set-current-buffer output-buffer)))
  
  (defun integer->unicode-geometric (string-integer)
    "Geometric blocks within the unicode table are from position 9632 (x25A0) to
    9727 (x25FF) with a total of 95 shapes."
    (if (str:emptyp string-integer)
        ""
        (format nil "&#x~X; " (+ 9631 (mod (parse-integer string-integer) 95)))))
  
  (define-command history-tree ()
    "Open a new buffer displaying the whole history tree."
    (let* ((markup:*auto-escape* nil)
           (buffer-name (format nil "*History*"))
           (output-buffer (or (find-if (lambda (b) (string= buffer-name (title b)))
                                       (buffer-list))
                              (nyxt/help-mode:help-mode
  