[Result’s convenience APIs] from John Sundell (https://www.swiftbysundell.com/tips/result-type-convenience-apis/)

Result.swift

let data: Data = ...
let decoder = JSONDecoder()

// This will create a Result<Model, Error> instance, which will contain
// 'success' if its expression succeeded, and 'failure' if it ended
// up throwing an error:
let result = Result {
    try decoder.decode(Model.self, from: data)
}

// The above API is really useful when we want to return a Result
// value from an asynchronous operation, for example by calling
// a completion handler:
completionHandler(result)

func decode(_ result: Result<Data, Error>) throws -> Model {
    // Using Result's 'get' method, we can either extract its
    // underlying value, or throw any error that it contains:
    let data = try result.get()
    let decoder = JSONDecoder()
    return try decoder.decode(Model.self, from: data)
}

let dataResult: Result<Data, Error> = ...

let stringResult = dataResult.map {
    String(decoding: $0, as: UTF8.self)
}