如何使用 Kotlin 将文本转换为按计数分组的单词列表？

Question

我有这样的字符串文本：

val text: String = "aa bb cc aa bb aa aa / <"

我首先尝试跳过像 <*/&^$ 这样的特殊字符，然后将单词分组到对象单词列表中：

data class Word(val id: Int, val text: String, val count: Int)

listOf(Word(1, aa, 4), Word(2, bb, 2), Word(3, cc, 1))

这是我的方法，但它需要 3 个循环，这很糟糕加上样板代码

 val wordWithCountMap = mutableMapOf<String, Int>()
 text.trim().split(" ").forEach { word ->
        if (word.isNotEmpty() && word.isNotBlank()) {
            val key = regex.replace(word, "")
            wordWithCountMap[key] = wordWithCountMap[word]?.plus(1) ?: 1
        }
    }

 val wordList = arrayListOf<Word>()
 wordWithCountMap.onEachIndexed { index, entry ->
      wordList.add(
         Word(
                id = index, text = entry.key,
                count = entry.value
         )
      )
  }

Answer 1

val text: String = "aa bb cc aa bb aa aa / <"

data class Word(
  val id: Int,
  val text: String,
  val count: Int
)

val result = text
  .split("\b".toRegex())
  .filter { it.any { char -> char.isLetterOrDigit() } }
  .groupingBy { it }
  .eachCount()
  .entries
  .sortedByDescending { it.value }   // mabye remove this line (see @mattFreake's comment below)
  .mapIndexed { index, textCount -> Word(index + 1, textCount.key, textCount.value) }

result.forEach(::println)

如何使用 Kotlin 将文本转换为按计数分组的单词列表？

How to transform text into list of words grouped by count using Kotlin?

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