Sharrp

public func attempt<T>(source source: String = __FUNCTION__, file: String = __FILE__, line: Int = __LINE__, closure: () throws -> T) -> Optional<T>{
  do {
    return try closure()
  } catch {
    let fileName = (file as NSString).lastPathComponent
    let report = "Error \(fileName):\(source):\(line):\n    \(error)"
    print(report)
    return nil
  }
}

Sharrp

// Find the first number greater than given, made up with the same digits
// 0 - lowest digit in input array of digits
func nextNumber(digits: [Int]) -> [Int]
{
    var next = digits
    for i in 1..<next.count
    {
        if next[i] < next[i-1] // First descending order
        {
            // Find the first greater than next[i]