André Jorgensen: Generic typealias can be used to simplify param types etctypealias Parser<A> = (String) -> [(A, String)] […] func parse<A>(stringToParse: String, parser: Parser) […] Finding Elements of Specific Type in Swift extension Array { func whereType<T>() -> [T] { compactMap { $0 as? T } // The function "compactMap(" in Swift is incredibly useful. […]