How to correctly put parameters in completion escaping without destroying the filter?

Question

Swift

i have structure:

struct APIResponce: Codable {
    let result: IsResult
}

struct IsResult: Codable {
    let items: [ResultItem]
    let lastID: Int
    let lastSortingValue: Double
    
    enum CodingKeys: String, CodingKey {
        case items
        case lastID = "lastId"
        case lastSortingValue
    }
}

Parsing function:

public func getTopStories(lastID: Int = 0, lastSortingValue: Double = 0, completion: @escaping (Result<[ResultItem], Error>)

do {
                    let json = try JSONDecoder().decode(APIResponce.self, from: data)
                    let obj = json.result.items.filter{$0.data != nil}
                    completion(.success(obj))
                }

Well, to get the lastID values, I replaced (Result<[ResultItem], Error>)with (Result<[IsResult], Error>)
and in the do block, respectively, we need to put

do {
                    let json = try JSONDecoder().decode(APIResponce.self, from: data)
                //   filter не работает т.к obj становится [ResulItem] , а completion [IsResult]
               //     let obj = json.result.items.filter{$0.data != nil}
                    completion(.success([json.filter]))
                }

There is another idea to process the result in the ViewController, but there I caught a lot of errors like:
cannot asign [ResultItem] expect [IsResult]
I commented out the idea:

private var result = [ResultItem]()
  //  private var pag = [IsResult]()
    private var viewModels = [NewsTableViewCellViewModel]()
    private var id = 0
    private var sortVal = 0.0
                }
        }
    }

    private func fetchTopStories() {
        APICaller.shared.getTopStories(lastID: id, lastSortingValue: sortVal) { [weak self] json in
            switch json {
            case .success(let result):

        //    case .success(let pag):
        //    self?.pag = result.items  // компилятор ругается
        //   self?.viewModels = result.items.compactMap({ viewModels in   // компилятор ругается

                self?.result = result
                self?.viewModels = result.compactMap({ viewModels in

                    // guard let uuid = viewModels.data?.blocks?.first(where: {$0.data.text == nil && $0.data.items != nil})?.data.items?.first?.image?.data?.uuid else { return nil }

                    // return NewsTableViewCellViewModel(
                    //     name: viewModels.data?.subsite?.name ?? "unknown",
                    //     author: viewModels.data?.author?.name ?? "No name",
                    //     title: viewModels.data?.title ?? "NO TITLE",
                    //     subtitle: viewModels.data?.blocks?.first?.data.text ?? "",
                    //     imageURL: URL(string: "https://leonardo.osnova.io/\(uuid.uuidString.lowercased())")
                    // )
                })
                DispatchQueue.main.async {
                    self?.tableView.reloadData()
                }
//                self?.id = pag.first?.lastID ?? 0
//                self?.sortVal = pag.first?.lastSortingValue ?? 0
            case .failure(let error):
                print(error)

The question itself: is it possible to "painlessly" add to the [ResultItem] which I put in the complition the lastID and lastSortingValue parameters?
Or will I have to change the whole escaping to put in complition [IsResult]? If so, then I don’t know if it will be possible to filter the incoming data from nil and put it in complition.

Answer 1

Sorry, but in my opinion you are already confused in your algorithms. You understand that you cannot assign a value of type A to a variable of type B, right? However, you try to do this and are surprised when the compiler swears.
If you need to change the type of the output parameter of a function, it is logical that you also need to change the functions that accept it.
No one knows better than you what you need. If you need to return IsResult - return it, if necessary [IsResult] - return it, if necessary [ResultItem] - then return it.
It seems to me that you are already confused in logic.