退出Recur循环在Clojure [英] Exit Recur Loop in Clojure

问题描述

我想跳出下面的循环，并返回best-min-move，当第10行计算为true。我已经看过输出与打印语句，当第10行评估为真，它找到我正在寻找，但继续重复的数据。在Clojure中有一种方法可以在语句计算结果为true时停止循环？或者，我应该使用除了循环之外的其他东西吗？

I'd like break out of the below loop and return the best-min-move when line 10 evaluates to true. I've looked at the output with print statements and when line 10 does evaluate to true, it finds the data that I'm looking for but continues to recur. In Clojure is there a way to stop the loop when a statement evaluates to true? Or should I be using something other than a loop recur?

(defn minimax [board max-mark min-mark depth best-score] 
  (loop [board board
     max-mark max-mark
     min-mark min-mark
     depth depth
     best-score best-score]
  (if (= best-score (best-min-score board max-mark min-mark depth))
   (best-max-move board max-mark min-mark depth)                     
   (do                                                               
      (if (= best-score (best-min-score board min-mark max-mark depth))
       (best-min-move board min-mark max-mark depth)              
       (recur 
         (b/make-move-on board (remaining-scores board max-mark min-mark depth) max-mark)                
           min-mark 
           max-mark 
           (inc depth) 
           (dec best-score)))))))

推荐答案

关于 loop

• 不是循环循环： recur 。


• code> loop 是一个 let ，形成一个 li>

• 您不能，也不能跳出循环： recur / li>


• It's not loop that loops: it's recur.
• loop is a let that forms a recur point.
• You don't and can't break out of a loop: recur breaks you into one.

loop 等效于设置和调用匿名函数。例如

loop is equivalent to setting up and calling an anonymous function. For example

(loop [n 5, s "Hello, world!"]
  (if (zero? n)
    (first s)
    (recur (dec n) (rest s))))

...等效于

((fn [n s]
  (if (zero? n)
    (first s)
    (recur (dec n) (rest s))))
 5 "Hello, world!")

由于某些性能损失， loop 可能已写为执行上述转型。

With some loss of performance, loop could have been written as a macro that carries out the above transformation.

至于您的代码：

有六个未定义功能。要清除编辑，我们

There are six undefined functions here. To clear compilation, we

(declare best-min-score 
         best-max-move
         best-min-move
         best-max-move
         make-move-on
         remaining-scores)

还有两个冗余形式。这些没有积极的伤害，但掩盖了代码。

There are also two redundant forms. These do no active harm but do obscure the code.

• 不需要循环：函数本身是一个合适的$ b $ c 单一形式。

• The loop is not needed: the function itself is a suitable target for recur.
• The do does nothing: it encloses a single form.

您的功能减少到

(defn minimax [board max-mark min-mark depth best-score] 
  (if (= best-score (best-min-score board max-mark min-mark depth))
    (best-max-move board max-mark min-mark depth)
    (if (= best-score (best-min-score board min-mark max-mark depth))
      (best-min-move board min-mark max-mark depth)              
      (recur 
       (make-move-on board (remaining-scores board max-mark min-mark depth) max-mark)                
       min-mark 
       max-mark 
       (inc depth) 
       (dec best-score)))))

---

虽然任何未定义的函数可能会重现，但最好的办法是 best-min-move 。

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