Scala Concordance List

import scala.io.Source

//read a file and build a concordance list of the tokens in the file
  //there's gotta be a nicer way to do this
  def two(fileName:String) = {
    val chunkSize = 1024
    Source.fromFile(fileName).getLines()
      // read in chunkSize lines into memory at once
      // From: http://stackoverflow.com/questions/6751463/iterate-over-lines-in-a-file-in-parallel-scala
      .grouped(chunkSize)
      .map { lines =>
        lines
         // Take advantage of Scala collection parallel processing
         .par
         // Get the words from all lines (split on one or more whitespace)
         .flatMap(line => line.split("\\s+"))
         // Group by unique words
         .groupBy(v => v)
         // Get the count 
         .map { case (word, words) => (word, words.size) }
         .toMap
      }
      // Each chunk is now a Map[String, Int] so we need to combine these
      .reduce { (map1,map2) =>
        // From: http://stackoverflow.com/questions/7076128/best-way-to-merge-two-maps-and-sum-the-values-of-same-key (2nd answer)
        map1 ++ map2.map{ case (k,v) => k -> (v + map1.getOrElse(k,0)) }
      }
  }