Bring some of AppKit's strongly typed names and identifiers to UIKit

UIKitCatchupToAppKit.swift

import UIKit

public extension UIStoryboard {

    public struct SceneDescriptor {
        public let name: UIStoryboard.Name
        public let identifier: UIStoryboard.SceneIdentifier

        public init(name: UIStoryboard.Name, identifier: UIStoryboard.SceneIdentifier) {
            self.name = name
            self.identifier = identifier
        }

        public func instantiateViewController() -> UIViewController {
            let storyboard = UIStoryboard(name: self.name)
            return storyboard.instantiateViewController(withIdentifier: self.identifier)
        }
    }

    public struct Name: Hashable, Equatable, RawRepresentable {
        public var rawValue: String

        public init(rawValue: String) {
            self.rawValue = rawValue
        }

        public init(_ rawValue: String) {
            self.rawValue = rawValue
        }
    }

    public struct SceneIdentifier: Hashable, Equatable, RawRepresentable {
        public var rawValue: String

        public init(rawValue: String) {
            self.rawValue = rawValue
        }

        public init(_ rawValue: String) {
            self.rawValue = rawValue
        }
    }

    public convenience init(name: UIStoryboard.Name, bundle storyboardBundleOrNil: Bundle? = nil) {
        self.init(name: name.rawValue, bundle: storyboardBundleOrNil)
    }

    public func instantiateViewController(withIdentifier identifier: UIStoryboard.SceneIdentifier) -> UIViewController {
        return self.instantiateViewController(withIdentifier: identifier.rawValue)
    }
}

public extension UIStoryboardSegue {

    public struct Identifier: Hashable, Equatable, RawRepresentable {
        public var rawValue: String

        public init(rawValue: String) {
            self.rawValue = rawValue
        }

        public init(_ rawValue: String) {
            self.rawValue = rawValue
        }
    }

    var segueIdentifier: UIStoryboardSegue.Identifier? {
        guard let identifier = self.identifier else {
            return nil
        }

        return UIStoryboardSegue.Identifier(rawValue: identifier)
    }

    public convenience init(identifier: UIStoryboardSegue.Identifier?, source: UIViewController, destination: UIViewController) {
        self.init(identifier: identifier?.rawValue, source: source, destination: destination)
    }

    public convenience init(identifier: UIStoryboardSegue.Identifier?, source: UIViewController, destination: UIViewController, performHandler: @escaping () -> Void) {
        self.init(identifier: identifier?.rawValue, source: source, destination: destination, performHandler: performHandler)
    }
}


// Use a tool to scan your project and automatically generate a list of names, identifiers, etc. 
//    I wrote a tool, Resourceror, to do this for AppKit, but I'm sure it could be adapted for UIKit pretty quickly: 
//    https://github.com/tonyarnold/resourceror

extension UIStoryboard.Name {
    static let login = UIStoryboard.Name(rawValue: "Login")
}

extension UIStoryboard.SceneIdentifier {
    static let usernameEntry = UIStoryboard.SceneIdentifier(rawValue: "UsernameEntryViewControllerIdentifier")
    static let passwordEntry = UIStoryboard.SceneIdentifier(rawValue: "PasswordEntryViewControllerIdentifier")
}

extension UIStoryboard.SceneDescriptor {
    static let passwordEntry = UIStoryboard.SceneDescriptor(name: .login, identifier: .passwordEntry)
}


// If your method takes any of these as an argument, you can shorten their use right down to just the name preceded by a period:

let descriptor: UIStoryboard.SceneDescriptor = .passwordEntry
let viewController = descriptor.instantiateViewController()