functional style of binary search

binarySearch.scala

def binarySearchFunctional(list: Array[Int], target: Int): Int = { 		
  def bsf(list: Array[Int], target: Int, start: Int, end: Int): Int = {
    if (start>end) return -1
    val mid = start + (end-start+1)/2
    list match {
      case (arr:Array[Int]) if (arr(mid)==target) => mid
      case (arr:Array[Int]) if (arr(mid)>target) => bsf(list, target, start, mid-1)
      case (arr:Array[Int]) if (arr(mid)<target) => bsf(list, target, mid+1, end)
    }
  }		
  bsf(list, target, 0, list.length-1)
}