A better way to be selective

["Henry S. Thompson" <ht@xxxxxxxxxxxxxxx>]

I hadn't realised the extent to which named ports and labelled sosofos
were supported.  Here's a basic template for selective processing, works in
jade-0.5 or 0.7:

(root (make simple-page-sequence
	    (make scroll
		  content-map: '((win #f))
		  (sosofo-discard-labeled (make sequence) 'lose))))

(define *winning-gis* '("TITLE" "FOOTNOTE"))

(default
  (if (member (gi) *winning-gis*)
      (make sequence label: 'win
	    (with-mode index (process-node-list (current-node))))
    ;; process only element daughters
    (make sequence label: 'lose)))

(mode index (default (make paragraph)))