Scala - Partial functions with orElse

OrElse.scala

import java.io._

val osURL: PartialFunction[Option[String], OutputStream] = {
  case Some(name) => new java.io.FileOutputStream(new java.io.File(name))
    if(name.contains(":"))
}

val osLocalFile: PartialFunction[Option[String], OutputStream] = {
  case Some(name) => new java.io.FileOutputStream(new java.io.File(name))
}

val osStdout: PartialFunction[Option[String], OutputStream] = {
  case _ => System.out
}

val makeOutputStream = osURL orElse osLocalFile orElse osStdout

val args1 = Seq.empty[String]
val os1 = makeOutputStream(args1.headOption)
val pw1 = new PrintWriter(os1)
pw1.write("In this case, this text is printed out to the console.\n")

val args2 = Seq("output.txt")
val os2 = makeOutputStream(args2.headOption)
val pw2 = new PrintWriter(os2)
pw2.write("In this case, this text is printed out to a file.\n")