在Clojure中，如何在嵌套地图中查找具有某些键的所有地图

Question

Let m be a nested map. How to find all the maps in m that have a some key.

For instance:

(def m {:a {:id 5}
        :d {:id 58}
        :x {:id 4 :c {:id 3 :d 4}}})

(recursive-filter m :id)

;; expected result: 
> ({:id 5} {:id 58} {:id 4 :c {:id 3 :d 4}} {:id 3})

Answer 1

You can use the following:

(def data {:a {:id 5}
           :d {:id 58}
           :x {:id 4 :c {:id 3 :d 4}}})

(defn recursive-filter [m f]
  (filter #(and (map? %) (f %))
          (tree-seq map? vals m)))

(recursive-filter data :id)

Answer 2

With inspiration from @Symfrog:

(defn recursive-filter [m k]
  (filter #(and (map? %) (contains? % k)) (tree-seq map? vals m)))