Remove projection if you don't want to println(dir)

WordFreq.scala

import java.io.{Closeable, File, FileWriter, PrintWriter}

val rootDir = new File("/home/virasak/.vim")
if (!rootDir.exists) throw new IllegalArgumentException(rootDir + " does not exist")

val counts = scala.collection.mutable.Map.empty[String, Int]
for {
  dir  <- rootDir.listFiles.projection if dir.isDirectory && println("Processing " + dir) == ()
  file <- dir.listFiles if file.isFile
  line <- scala.io.Source.fromFile(file, "ISO-8859-1").getLines
  word <- line.split("""\W+""").map(_.toLowerCase)
} counts(word) = counts.getOrElse(word, 0) + 1

val countList = counts.toList
println("Writing counts in decreasing order")
write(countList.sort(_._2 > _._2), "counts-descreasing-scala")

println("Writing counts in alphabetical order")
write(countList.sort(_._1 < _._1), "counts-alphabetical-scala")

def write(counts: List[(String,Int)], fileName: String) {
  using(new PrintWriter(new FileWriter(fileName))) { out =>
    for ((word, count) <- counts) out.println(word + "\t" + count)
  }
}

def using[A <: Closeable, B](a: A)(f: A => B) = try { f(a) } finally { a.close }