4clojure 题解 Map Construction

把两个序列合并成一个map，不允许使用zipmap

Write a function which takes a vector of keys and a vector of values and constructs a map from them.

	(= (__ [:a :b :c] [1 2 3]) {:a 1, :b 2, :c 3})
	(= (__ [1 2 3 4] ["one" "two" "three"]) {1 "one", 2 "two", 3 "three"})
	(= (__ [:foo :bar] ["foo" "bar" "baz"]) {:foo "foo", :bar "bar"})

用loop实现很简单

(fn [keys vals]
  (loop [map {}
         ks (seq keys)
         vs (seq vals)]
    (if (and ks vs)
      (recur (assoc map (first ks) (first vs))
             (next ks)
             (next vs))
      map)))