compose method and function

Common.scala

def readUserScores(fileName: String): List[UserScore] = {
    val serocs = ((Nil: List[UserScore]) /:
     io.Source.fromFile(fileName).getLines()
//       .map(_.split("\t")).map(array2Pair(_))
//       .map(((x:String) => x.split("\t")) andThen array2Pair)
//       .map(((_:String).split("\t")) andThen array2Pair)
       .map( array2Pair _ compose (_.split("\t")))
      ) { case (l, e) => e :: l }

      serocs.reverse
  }