Question

在Clojure中，我可以使用类似这样的解决方案：Compact Clojure code for regular expression matches and their position in string，即创建re-matcher并从中提取信息，但重新匹配器似乎没有在ClojureScript中实现。在ClojureScript中完成同样的事情有什么好方法？

修改

我最后编写了一个补充函数，以便保留正则表达式的修饰符，因为它被re-pos吸收：

(defn regex-modifiers
  "Returns the modifiers of a regex, concatenated as a string."
  [re]
  (str (if (.-multiline re) "m")
       (if (.-ignoreCase re) "i")))

(defn re-pos
  "Returns a vector of vectors, each subvector containing in order:
   the position of the match, the matched string, and any groups
   extracted from the match."
  [re s]
  (let [re (js/RegExp. (.-source re) (str "g" (regex-modifiers re)))]
    (loop [res []]
      (if-let [m (.exec re s)]
        (recur (conj res (vec (cons (.-index m) m))))
        res))))

Answer 1

您可以使用JS RegExp对象的.exec方法。返回的匹配对象包含index属性，该属性对应于字符串中匹配的索引。

目前clojurescript不支持使用g模式标志构建正则表达式文字（请参阅CLJS-150），因此您需要使用RegExp构造函数。以下是链接页面中re-pos函数的clojurescript实现：

(defn re-pos [re s]
  (let [re (js/RegExp. (.-source re) "g")]
    (loop [res {}]
      (if-let [m (.exec re s)]
        (recur (assoc res (.-index m) (first m)))
        res))))

cljs.user> (re-pos "\\w+" "The quick brown fox")
{0 "The", 4 "quick", 10 "brown", 16 "fox"}
cljs.user> (re-pos "[0-9]+" "3a1b2c1d")
{0 "3", 2 "1", 4 "2", 6 "1"}

如何在ClojureScript中获取正则表达式匹配的位置？

1 个答案: