AssociatedValuesAndRawRepresentable.swift

enum Scene {
    case home
    case level(Int)
    case levelSelection
}

extension Scene: RawRepresentable {
    typealias RawValue = String
    
    init?(rawValue: String) {
        switch rawValue {
        case "home":
            self = .home
        case "levelSelection":
            self = .levelSelection
        default:
            guard let range = rawValue.range(of: "level", options: .anchored) else { return nil }
            guard let number = Int(rawValue.suffix(from: range.upperBound)) else { return nil }
            self = .level(number)
        }
    }
    
    var rawValue: String {
        switch self {
        case .home:
            return "home"
        case .levelSelection:
            return "levelSelection"
        case .level(let number):
            return "level\(number)"
        }
    }
}


// Examples:
// Scene.home
let home = Scene(rawValue: "home")

// Scene.level(1)
let level1 = Scene(rawValue: "level1")
let paddedLevel1 = Scene(rawValue: "level001")