Clojure循环读取一个额外的

Question

当长度为4时，循环执行5次。从流中读取5个字符。

(loop [i (.read stream)  result ""  counter length]
    (let [c (char i)]
      (println "=>" c)
      (if (zero? counter)
        result
        (recur (.read stream) (str result c) (dec counter)))))

Answer 1

在执行zero?之前，您应该测试read。请注意，即使read == 0开始，您的版本也会调用length一次。

(loop [result "" counter length]
  (if (zero? counter)
    result
    (let [c (char (.read stream))]
      (println "=>" c )
      (recur (str result c) (dec counter)))))

另一种避免明确loop：

的方法

(apply str 
       (take length 
             (repeatedly #(let [c (char (.read stream))]
                            (println "=>" c) c)))))

Answer 2

我不知道clojure，但它看起来像你正在以“结果”的形式再次阅读流，这在CL中是最终的吗？