◊(Local Yarn Code "Diff")

;; Provided tag functions:
(define (html-link . args)
  `(link& [[ref ,(format "~a" (first args))]] ,@(rest args)))

(define (html-url ref url)
  (hash-set! link-urls (format "~a" ref) url))
  (hash-set! link-urls (format "~a" ref) url) "")

;; Private use (by html-root):
(define (decode-link-urls tx)
  (cond [(eq? (get-tag tx) 'link&)
         (let* ([url-ref (attr-ref tx 'ref)]