Scala implementation of threshold edit distance

ThresholdLevenshtein.scala

def thresholdLevenshtein(_s: String, _t: String, threshold: Int): Int = {
  val (s, t) = if (_s.length > _t.length) (_s, _t) else (_t, _s)
  val slen = s.length
  val tlen = t.length

  var prev = Array.fill[Int](tlen+1)(Int.MaxValue)
  var curr = Array.fill[Int](tlen+1)(Int.MaxValue)
  for (n <- 0 until math.min(tlen+1, threshold+1)) prev(n) = n

  for (row <- 1 until (slen+1)) {
     curr(0) = row
     val min = math.min(tlen+1, math.max(1, row - threshold))
     val max = math.min(tlen+1, row + threshold + 1)
     // println("row[" + row + "] min=" + min + " max=" + max)

     if (min > 1) curr(min-1) = Int.MaxValue
     for (col <- min until max) {
       curr(col) = if (s(row-1) == t(col-1)) prev(col-1)
                   else math.min(prev(col-1), math.min(curr(col-1), prev(col))) + 1
     }
     // println("row[" + row + "]: " + curr.mkString(" "))
     prev = curr
     curr = Array.fill[Int](tlen+1)(Int.MaxValue)
  }

  prev(tlen)
}