anchor.diff:                                       (modifiers '())
                                      &allow-other-keys)
     "Return non-nil to let platform port load URL.
  -Return nil otherwise.
  -
  -Deal with URL with the following rules:
  -- If IS-NEW-WINDOW is non-nil or if C-button1 was pressed, load in new buffer.
  -- If IS-KNOWN-TYPE is nil, download the file.  (TODO: Implement it!)
  -- Otherwise return non-nil to let the platform port load the URL."
  -  (declare (ignore event-type))         ; TODO: Do something with the event type?
  +   Return nil otherwise.
  +
  +   Deal with URL with the following rules:
  +   - If IS-NEW-WINDOW is non-nil or if C-button1 was pressed, load in new buffer.
  +   - If IS-KNOWN-TYPE is nil, download the file.  (TODO: Implement it!)
  +   - Otherwise return non-nil to let the platform port load the URL."
  +  (declare (ignore event-type)) ; TODO: Do something with the event type?
     (cond
       ((or is-new-window
            ;; TODO: Streamline the customization of this binding.
  
positive.code:      (log:debug "Forwarding back to platform port: ~a" url)
       t)))
  
  ;; Return non-nil to tell the platform port to load the URL.
  (defun request-resource
      (buffer-id url cookies event-type is-new-window
       is-known-type mouse-button modifiers)
    (unless (member-string event-type '("other"
                                        "link-click"
                                        "form-submission"
                                        "form-resubmission"
                                        "backward-or-forward"
                                        "reload"))
      (setf event-type "other"))
    (setf event-type (intern event-type "KEYWORD"))
    ;; TODO: We need to define an EVENT type, e.g. with
    ;; (deftype event () '(member :other :link-click ...))
    ;; https://stackoverflow.com/questions/578290/common-lisp-equivalent-to-c-enums#
    (log:debug "Request resource ~s with mouse ~s, modifiers ~a" url mouse-button modifiers)
    (let ((buffer (gethash buffer-id (buffers *interface*))))
      (if buffer
          (funcall (resource-query-function buffer)
                   buffer
                   :url url
                   :cookies cookies
                   :event-type event-type
                   :is-new-window is-new-window
                   :is-known-type is-known-type
                   :mouse-button mouse-button
                   :modifiers modifiers)
          (progn
            (log:debug "no buffer of id '~a'~&" buffer-id)
            t))))
  
  ;; Convenience methods and functions for users of the API.
  
  @export
  (defun current-buffer ()
  
negative.code:     ((not is-known-type)
       (log:info "Buffer ~a downloads ~a" buffer url)
       (download url :proxy-address (proxy-address buffer :downloads-only t)
                     :cookies cookies)
       (unless (find-buffer 'download-mode)
         (download-list))
       nil)
  