Cream Lisp: Find All Parents

(defnodefun parents (&optional selector)
  "Get the ancestors of each element, optionally filtered by a selector."
    (loop for parent = (dom:parent-node node) then (dom:parent-node parent)
       while (not (dom:document-p parent))
       if (or (not selector) (css:node-matches? parent selector))
       collect parent))