Bubble sort functional. Stop if list is sorted without go through all possible combinations

bubblesort.scala

import scala.annotation.tailrec
def bubbleSort(l: Seq[Int]): Seq[Int] = {
  def isSorted(s: Seq[Int]) = ((false, Int.MinValue) /: s){
    case ((flag, prev), current) =>
      if (prev <= current) (true, current) else (false, Int.MaxValue)
  }._1
  def _bubbleSort(m: Seq[Int]): Seq[Int] = m match {
    case x +: y +: Nil => if (x > y) y +: x +: Nil else x +: y +: Nil
    case x +: y +: zs =>
      if (x > y) y +: _bubbleSort(x +: zs)
      else x +: _bubbleSort(y +: zs)
  }
  @tailrec
  def goSort(s: Seq[Int]): Seq[Int] = if (isSorted(s)) s
    else goSort(_bubbleSort(s))
  goSort(_bubbleSort(l))
}
bubbleSort(Seq(-1000, 101, 30, 4, -100, 1, 4, 3, 1, 2, -100))