通过调用函数及其键和值创建嵌套clojure映射

Question

{:first 
  {:value1 
    {subvalue1, subvalue2 ..} 
   :value2 
    {subvalue2-1,subvalue2-2}}    
 :second
  {:value3 
    {:subvalue3-1,:subvalue3-2}..}..}

Answer 1

这个函数有点冗长，但可以做您需要它做的事情：

(defn rec-update
  [m f]
  (let [g (fn g [m args]
            (into {}
                  (for [[k v] m]
                    (if (instance? java.util.Map v)
                      [k (g v (conj args (name k)))]
                      [k (into {} (map #(let [args (into args [(name k) (name %)])]
                                          [(keyword %) (f args)])
                                       v))]))))]
    (g m [])))

f参数应该是一个接受参数集合并返回结果向量的函数。下面是一个样本，它选取了随机响应的随机数：

(defn make-request
  [params]
  (vec (repeatedly (+ 1 (rand-int 3)) #(rand-nth ["r1" "r2" "r3"]))))

虽然下面的示例没有演示，但是给这个函数的params实际上是到那一点为止的嵌套值。

(def m {:first ["val1" "val2" "val3"], :second ["val4" "val5"]})

(rec-update m make-request)
=>
{:first {:val1 ["r2" "r2" "r3"], :val2 ["r2" "r2"], :val3 ["r1" "r3"]},
 :second {:val4 ["r3" "r3"], :val5 ["r2" "r1"]}}

(rec-update *1 make-request)
=>
{:first {:val1 {:r2 ["r1" "r3" "r2"], :r3 ["r3" "r2"]},
         :val2 {:r2 ["r1" "r1"]},
         :val3 {:r1 ["r2"], :r3 ["r1" "r2" "r3"]}},
 :second {:val4 {:r3 ["r3" "r2"]}, :val5 {:r2 ["r1"], :r1 ["r2" "r3"]}}}