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我知道正则表达式可用于编写检查器来检查括号的开始和结束符号对：

例如。a.[b.[c.d]].e屈服值a, [b.[c.d]], 和e

如何编写一个可以找出相同符号的开始和结束括号的正则表达式

例如。a.|b.|c.d||.e将产生值a,|b.|c.d||和e

更新

感谢所有的评论。我必须为这个问题提供一些背景信息。我基本上想模仿javascript语法

a.hello is a["hello"] or a.hello
a.|hello| is a[hello]
a.|b.c.|d.e||.f.|g| is a[b.c[d.e]].f[g]

所以我想要做的是将符号分解为：

 [`a`, `|b.c.|d.e||`, `f`, `|g|`]

如果它们被管道引用，然后通过它们重复

我在这里有一个没有管道的语法实现：

https://github.com/zcaudate/purnam

我真的希望不使用解析器，主要是因为我不知道如何使用，而且我认为它不能证明必要的复杂性是合理的。但如果正则表达式不能削减它，我可能不得不这样做。

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1 回答 1

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感谢@m.buettner 和@rafal，这是我在clojure 中的代码：

有一个normal-mode和pipe-mode。按照 m.buettner 的描述：

帮手：

(defn conj-if-str [arr s]
  (if (empty? s) arr
      (conj arr s)))

(defmacro case-let [[var bound] & body]
  `(let [~var ~bound]
     (case ~var ~@body)))

管道模式：

(declare split-dotted) ;; normal mode declaration

(defn split-dotted-pipe   ;; pipe mode
  ([output current ss] (split-dotted-pipe output current ss 0))
  ([output current ss level]
      (case-let
       [ch (first ss)]
       nil (throw (Exception. "Cannot have an unpaired pipe"))
       \|  (case level
             0 (trampoline split-dotted
                           (conj output (str current "|"))
                           "" (next ss))
             (recur output (str current "|") (next ss) (dec level)))
       \.  (case-let
            [nch (second ss)]
            nil (throw (Exception. "Incomplete dotted symbol"))
            \|  (recur output (str current ".|") (nnext ss) (inc level))
            (recur output (str current "." nch) (nnext ss) level))
       (recur output (str current ch) (next ss) level))))

正常模式：

(defn split-dotted
  ([ss]
     (split-dotted [] "" ss))
  ([output current ss]
     (case-let
      [ch (first ss)]
       nil (conj-if-str output current)
       \.  (case-let
            [nch (second ss)]
            nil (throw (Exception. "Cannot have . at the end of a dotted symbol"))
            \|  (trampoline split-dotted-pipe
                            (conj-if-str output current) "|" (nnext ss))
            (recur (conj-if-str output current) (str nch) (nnext ss)))
       \|  (throw (Exception. "Cannot have | during split mode"))
       (recur output (str current ch) (next ss)))))

测试：

(fact "split-dotted"
  (js/split-dotted "a") => ["a"]
  (js/split-dotted "a.b") => ["a" "b"]
  (js/split-dotted "a.b.c") => ["a" "b" "c"]
  (js/split-dotted "a.||") => ["a" "||"]
  (js/split-dotted "a.|b|.c") => ["a" "|b|" "c"]
  (js/split-dotted "a.|b|.|c|") => ["a" "|b|" "|c|"]
  (js/split-dotted "a.|b.c|.|d|") => ["a" "|b.c|" "|d|"]
  (js/split-dotted "a.|b.|c||.|d|") => ["a" "|b.|c||" "|d|"]
  (js/split-dotted "a.|b.|c||.|d|") => ["a" "|b.|c||" "|d|"]
  (js/split-dotted "a.|b.|c.d.|e|||.|d|") => ["a" "|b.|c.d.|e|||" "|d|"])

(fact "split-dotted exceptions"
  (js/split-dotted "|a|") => (throws Exception)
  (js/split-dotted "a.") => (throws Exception)
  (js/split-dotted "a.|||") => (throws Exception)
  (js/split-dotted "a.|b.||") => (throws Exception))
于 2013-05-12T01:45:30.223 回答