Question

以下代码尝试计算次数＆＃34; Apple＆＃34;出现在HTML文件中。

object Question extends App {

  def validWords(fileSentancesPart: List[String], wordList: List[String]): List[Option[String]] =
    fileSentancesPart.map(sentancePart => {
      if (isWordContained(wordList, sentancePart)) {
        Some(sentancePart)
      } else {
        None
      }

    })

    def isWordContained(wordList: List[String], sentancePart: String): Boolean = {

    for (word <- wordList) {
      if (sentancePart.contains(word)) {
        return true;
      }
    }

    false

  }

  lazy val lines = scala.io.Source.fromFile("c:\\data\\myfile.txt" , "latin1").getLines.toList.map(m => m.toUpperCase.split(" ")).flatten

  val vw = validWords(lines,   List("APPLE")) .flatten.size

  println("size is "+vw)


}

根据Scala代码，计数为79。但是当我用文本编辑器打开文件时，它会找到81个单词＆＃34; Apple＆＃34;遏制。搜索不区分大小写。可以找出bug的位置吗？（我假设错误是我的代码，而不是文本编辑器！）

我已经编写了几个测试，但代码似乎在这些简单的用例中表现得如预期：

import scala.collection.mutable.Stack;
import org.scalatest.FlatSpec;
import org.scalatest._;

class ConvertTes extends FlatSpec {

  "Valid words" should "be returned" in {

    val fileWords = List("this" , "is" , "apple" , "applehere")
    val validWords = List("apple")

    lazy val lines = scala.io.Source.fromFile("c:\\data\\myfile.txt" , "latin1").getLines.toList.map(m => m.toUpperCase.split(" ")).flatten

    val l : List[String] = validWords(fileWords, validWords).flatten

    l.foreach(println)

  }

    "Entire line " should "be returned for matched word" in {

    val fileWords = List("this" , "is" , "this apple is an" , "applehere")
    val validWords = List("apple")

    val l : List[String] = validWords(fileWords, validWords).flatten

    l.foreach(println)

  }


}

上面的代码中正在解析的HTML文件（称为＆＃34; c：\ data \ myfile.txt＆＃34;）：

https://drive.google.com/file/d/0B1TIppVWd0LSVG9Edl9OYzh4Q1U/view?usp=sharing

有关上述代码替代品的任何建议欢迎。

认为我的问题是根据@Jack Leow评论。代码：

  val fileWords = List("this", "is", "this appleisapple an", "applehere")
  val validWords = List("apple")

  val l: List[String] = validWords(fileWords, validWords).flatten

  println("size : " + l.size)

打印尺寸为2，应为3

Answer 1

我认为您应该执行以下操作：

def validWords(
  fileSentancesPart: List[String],
  wordList: List[String]): List[Option[String]] =

  fileSentancesPart /* add flatMap */ .flatMap(_.tails)
    .map(sentancePart => {
      if (isWordContained(wordList, sentancePart)) {
        Some(sentancePart)
      } else {
        None
      }
    })

def isWordContained(
  wordList: List[String],
  sentancePart: String): Boolean = {

  for (word <- wordList) {
    //if (sentancePart.contains(word)) {
    if (sentancePart.startsWith(word)) { // use startsWith
      return true;
    }
  }
  false
}

Answer 2

您可以使用带有Source迭代器的正则表达式：

val regex = "([Aa]pple)".r
val count = Source.fromFile("/test.txt").getLines.map(regex.findAllIn(_).length).sum

计算文件中单词的出现次数

2 个答案: