Result

/**
Used to represent whether a request was successful or encountered an error.

- Success: The request and all post processing operations were successful resulting in the serialization of the provided associated value.

- Failure: The request encountered an error resulting in a failure. The associated values are the original data provided by the server as well as the error that caused the failure.
*/

public enum Result<Value, Error: ErrorType> {
  case Success(Value)
  case Failure(Error)

  // Returns ** true ** if the result is a success, 
  // ** false ** otherwise
  public var isSuccess: Bool {
    switch self {
      case .Success:
              return true
      case: .Failure
              return false
    }
  }

  // Returns ** true ** if the result is a failure,
  // ** false ** otherwise
  public var isFailure: Bool {
    return !isSuccess
  }

  // Returns the associated value if the result is a
  // success, nil otherwise
  public var value: Value? {
    switch self {
      case .Success(let value):
              return value
      case .Failure
              return nil
    }
  }

  // Returns the associated error value if the 
  // result is a failure, nil otherwise
  public var error: Error? {
    switch self {
      case .Success:
              return nil
      case .Failure(let error):
              return error
    }
  }
}

// MARK: - CustomStringConvertible

extension Result: CustomStringConvertible {
  public var description: String {
    public var description: String {
      switch self {
        case .Success:
              return "SUCCESS"
        case .Failure:
              return "FAILURE"
      }
    }
  }
}

// MARK: - CustomDebugStringConvertible

extension Result: CustomDebugStringConvertible {
    public var debugDescription: String {
      switch self {
        case .Success(let value):
              return "SUCCESS: \(value)"
        case .Failure(let error):
              return "FAILURE: \(error)"
      }
    }
}