Swift中使用协议的加载器

protocol DataLoader {
    func loadData(completion: @escaping (Result<Data, Error>) -> Void)
}

import Foundation

// 定义数据加载器协议
protocol DataLoader {
    func loadData(completion: @escaping (Result<Data, Error>) -> Void)
}

// 实现一个简单的网络数据加载器
class NetworkDataLoader: DataLoader {
    func loadData(completion: @escaping (Result<Data, Error>) -> Void) {
        guard let url = URL(string: "https://api.example.com/data") else {
            completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "Invalid URL"])))
            return
        }
        
        URLSession.shared.dataTask(with: url) { data, response, error in
            if let error = error {
                completion(.failure(error))
                return
            }
            
            guard let data = data else {
                completion(.failure(NSError(domain: "", code: -1, userInfo: [NSLocalizedDescriptionKey: "No data received"])))
                return
            }
            
            completion(.success(data))
        }.resume()
    }
}

// 使用数据加载器
let loader: DataLoader = NetworkDataLoader()
loader.loadData { result in
    switch result {
    case .success(let data):
        print("Data loaded successfully: \(data)")
    case .failure(let error):
        print("Failed to load data: \(error.localizedDescription)")
    }
}