(in-package whitespace.utils)
 (lquery:define-lquery-list-function tag-name (nodes &rest tags)
   "Manipulate elements on the basis of there tag-name.
    With no arguments, return their names else return
    the corresponding tags."
   (if (null tags)
     (map 'vector #'plump:tag-name nodes)
     (apply #'vector
            (loop for node across nodes
                  if (find (plump:tag-name node) tags :test #'string=)
                  collect node))))