什么`：-`在clojure的core.typed中意味着什么？

Question

做什么:- 这个代码来自core.typed库？

(t/ann play-many [(ta/Chan RPSResult) t/Int -> (t/Map t/Any t/Any)])
(defn play-many
  "Play n matches from out-chan and report a summary of the results."
  [out-chan n]
  (t/loop [remaining :- t/Int, n                          ;; <======== This line
           results :- (t/Map PlayerName t/Int), {}]
    (if (zero? remaining)
      results
      (let [[m1 m2 winner] (a/<!! out-chan)]
        (assert m1)
        (assert m2)
        (assert winner)
        (recur (dec remaining)
               (merge-with + results {winner 1}))))))

Answer 1

如上所述， :-只是一个关键字。 但是，在您的上下文中，它是core.typed的注释的一部分，将循环绑定标记为特定类型：

(t/loop [remaining :- t/Int, n
         results :- (t/Map PlayerName t/Int), {}]
  ...)

这意味着remaining是一个整数，而results是一个将玩家名称与整数相关联的地图。 这些可以使用core.typed的类型检查器进行验证。

Answer 2

:-是单个字符的关键字， - 。

user=> :-
:-
user=> (class :-)
clojure.lang.Keyword