sum and max in scala, tail recursive without an inner helper method

gistfile1.txt

  //If we have a list with at least two elements sum them and add them to the rest of the list
  //else return the head of the list
  @tailrec
  def sum(xs: List[Int]): Int = xs match {
    case h :: i :: rest => sum(h + i :: rest) //we have a list with at least two elements
    case _ => xs.head
  }
  
  //If we have a list with at least two elements, remove the smallest and recurse
  //else return the head of the list/We have
  @tailrec
  def max(xs: List[Int]): Int = xs match {
    case h :: i :: rest => if (h > i) max(h :: rest) else max(i :: rest)
    case _ => xs.head
  }

nice