Scala file splitter/group by keyword

scala-file-groupby-keyword.scala

//val lines = scala.io.Source.fromFile("test.txt", "utf-8").getLines.toList
val lines = List("HEAD     000001","HEAD     000002","HEAD     000002","HEAD     000002","HEAD     000003","HEAD     000003")

val keywords = lines.map(x => x.substring(9, 15)).distinct

def groupByKeyword(lines: List[String], keywords: List[String]): List[List[String]] = keywords match {
	case keyword :: Nil => lines.groupBy(x => x.substring(9, 15).contains(keyword)).get(true).toList
	case keyword :: _keywords => {
		val mapped = lines.groupBy(x => x.contains(keyword))
		mapped.get(true).toList.head :: groupByKeyword(mapped.get(false).toList.head, _keywords)
	}
	case _ => Nil
} 

val res1 = groupByKeyword(lines, keywords)

Print sub lists size

res1.foreach(x => println (x.size))

Sum sub lists size

res1.map(x => x.size).sum