DrinksCodable5.swift

struct Drinks: Decodable {
    let drinks: [Drink]

    enum DrinksKey: CodingKey {
        case drinks
    }

    enum DrinkTypeKey: CodingKey {
        case type
    }

    enum DrinkTypes: String, Decodable {
        case water = "water"
        case orangeJuice = "orange_juice"
        case beer = "beer"
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: DrinksKey.self)
        var drinksArrayForType = try container.nestedUnkeyedContainer(forKey: DrinksKey.drinks)
        var drinks = [Drink]()

        var drinksArray = drinksArrayForType
        while(!drinksArrayForType.isAtEnd) {
            let drink = try drinksArrayForType.nestedContainer(keyedBy: DrinkTypeKey.self)
            let type = try drink.decode(DrinkTypes.self, forKey: DrinkTypeKey.type)
            switch type {
            case .water, .orangeJuice:
                print("found drink")
                drinks.append(try drinksArray.decode(Drink.self))
            case .beer:
                print("found beer")
                drinks.append(try drinksArray.decode(Beer.self))
            }
        }
        self.drinks = drinks
    }
}