sweep.scala

class MineSweeper(val input:String) { 
  val grid = input.split("\n").map(_.toArray)

  def isCellBomb(cell:(Int, Int)) = { 
    for{
        row <- grid.lift(cell._1)
        cell <- row.lift(cell._2) 
        if(cell == '*')
      } yield 1
  }

  private def nearbyCells(x:Int, y:Int) = {
    for{ 
      row <- x-1 to x+1
      col <- y-1 to y+1
    } yield (row,col)
  }

  private def score(x:Int, y:Int) : String = isCellBomb(x,y) match { 
    case Some(_) => " " 
    case None => nearbyCells(x,y).flatMap(isCellBomb).sum.toString
  }

  def solve() = grid.indices.map( x => grid(x).indices.map( y => score(x,y)))
}

object MineSweeper {

  def apply(input:String) = { 
    new MineSweeper(input);
  }
}

val input = "..*\n...\n*..";
val sollution = MineSweeper(input).solve()

sollution.foreach(x => println(x.mkString))