Enums with Associated Values that conform to NSCoding

playground.swift

// Inspiration: https://gist.github.com/NinoScript/47819cf6fe36d6845aee32d19b423e9b
//: Playground - noun: a place where people can play
import UIKit

enum SavableEnum {
    case simpleCase
    case associatedValue(String)
    case anotherAssociated(Int)
}
extension SavableEnum {
    enum Base: String {
        case simpleCase
        case associatedValue
        case anotherAssociated
    }
    var base: Base {
        switch self {
        case .simpleCase:        return .simpleCase
        case .associatedValue:   return .associatedValue
        case .anotherAssociated: return .anotherAssociated
        }
    }
}

class SavableEnumWrapper: NSObject, NSCoding {
    var e: SavableEnum
    
    // Memberwise initializer
    init(e: SavableEnum) {
        self.e = e
    }
    
    // MARK: NSCoding
    required convenience init?(coder decoder: NSCoder) {
        guard
            let rawCase = decoder.decodeObject(forKey: "case") as? String,
            let base = SavableEnum.Base(rawValue: rawCase)
            else { return nil }
        
        let e: SavableEnum
        switch base {
        case .simpleCase:
            e = .simpleCase
        case .associatedValue:
            guard
                let value = decoder.decodeObject(forKey: "value") as? String
                else { return nil }
            e = .associatedValue(value)
        case .anotherAssociated:
            let value = decoder.decodeInteger(forKey: "value")
            e = .anotherAssociated(value)
        }
        self.init(e: e)
    }
    
    func encode(with aCoder: NSCoder) {
        aCoder.encode(e.base.rawValue, forKey: "case")
        switch e {
        case .simpleCase: break
        case .associatedValue(let value):   aCoder.encode(value, forKey: "value")
        case .anotherAssociated(let value): aCoder.encodeCInt(Int32(value), forKey: "value")
        }
    }
}

let savedEnum = SavableEnumWrapper(e: .anotherAssociated(154))
let arcvd = NSKeyedArchiver.archivedData(withRootObject: savedEnum)
let unarc = NSKeyedUnarchiver.unarchiveObject(with: arcvd)
let retreivedEnum = unarc as? SavableEnumWrapper
retreivedEnum?.e

print("sicket test")

if let gekkie = retreivedEnum {
    if case let SavableEnum.anotherAssociated(yolo) = gekkie.e {
        print("hee", yolo)
    }
}