Method that loops through each tile, with a callback that return the col, row and tile definition.

SKTileMapNode+Extension.swift

extension SKTileMapNode {
  
  func loopThroughTiles(completionClosure: (_ col: Int, _ row: Int, _ tile: SKTileDefinition?) -> ()) {
    for col in 0..<numberOfColumns {
      for row in 0..<numberOfRows {
        completionClosure(col, row, tileDefinition(atColumn: col, row: row))
      }
    }
  }
  
}