WordCount

WordCount.scala

// Based on Fantom's word count example here: http://blog.joda.org/2011/11/guide-to-evaluating-fantom.html
// I'm commenting the lines that need changing, and leaving a few of them uncommented, 
// as they are the same

// class WordCount {
   object WordCount {
//  Void main(Str[] args) {
    def main(args: Array[String]) {

      if (args.size != 1) {
//      echo("usage: Wordcount <file>")
        println("usage: WordCount <file>")
//      Env.cur.exit(-1)
        sys exit -1
    }

      // Set up an empty map to count each word, setting default for each value to zero
//    wordCounts := Str:Int[:] { def = 0 }
      val wordCounts = collection.mutable.Map[String, Int]() withDefaultValue 0

      // Open the file, read each line in order
//    file := Uri(args[0]).toFile
      val file = io.Source fromFile args(0)
//    file.eachLine |line| {
      file.getLines foreach { line =>
        // skip empty lines
        if (line.trim.isEmpty) return

        // split and trim on whitespace into words
//      words := line.split
        val words = line split "\\s+"

        // count each one
//      words.each |word| { wordCounts[word] += 1 }
        words foreach { word => wordCounts(word) += 1 }
      }

      // Show each word found, with its count, in alphabetical order
//    wordCounts.keys.sort.each |key| {
      wordCounts.keys.toSeq.sorted foreach { key =>
//      echo("$key ${wordCounts[key]}")
        println(key+" "+wordCounts(key))
      }
    }
  }

start from line 25:

file.getLines.filteNot(_.isEmpty).flatMap(_ split """\s+""").groupBy(_).map(case (word, wordList) => (word, wordList.size)).sortBy(_._1).foreach(case (word, count) => println(word + " " + count)

You forgot the trim. Also, "groupBy(_)" will not do what you expect it to -- try "groupBy(x => x)" or "groupBy(identity)" instead. Also, neither groupBy nor sortBy are members of Iterator, and converting the whole file into a sequence would have nasty performance.

fixed version:

file.getLines.filterNot(.trim.isEmpty).flatMap( split """\s+""").toSeq.groupBy(identity).mapValues(.size).toSeq.sortBy(._1).foreach{ case (word, count) => println(word+" "+count) }

call to toSeq creates Stream

Thanks, @dcsobral and @kaja47.
learned two more things about scala:

• Predef.identity
• mapValues

And here is the par version:

file.getLines.filterNot(_.trim.isEmpty).toStream.par.flatMap(_ split """\s+""").groupBy(identity).map{case (word, wordList) => (word, wordList.size)}.toStream.sortBy(_._1).foreach{case (word, count) => println(word + " " + count)}

We love single line :-)