gistfile1.clj

(defn childreno [node children]
  (fresh [r]
    (resto node r)
    (resto r children)))

(defn nodes-existo [condition nodes out]
  (fresh [node remaining-nodes]
    (conso node remaining-nodes nodes)
    (conde
      [(condition node) (== node out)]
      [(fresh [children]
        (childreno node children)
        (nodes-existo condition children out))]
      [(nodes-existo condition remaining-nodes out)])))

(defn get-elements-by-class-name [dom class-name]
  (run* [q]
    (nodes-existo #(has-classnameo % class-name) dom q)))