data Undefined : Typeundefined : UndefinedThe `undefined` constant
isUndefined : a -> BoolTests, whether a value of questionable origin is undefined
data UndefOr : Type -> Typeundef : UndefOr adef : a -> UndefOr adata Optional : Type -> Typeoptional : Lazy b -> (a -> b) -> Optional a -> bfromOptional : Lazy a -> Optional a -> aoptionalToUndefOr : Optional a -> UndefOr aoptUp : {auto 0 {conArg:5464} : JSType a} -> Optional a -> {auto 0 _ : Elem b (Types a)} -> UndefOr bomyUp : {auto 0 {conArg:5500} : JSType a} -> Optional (Maybe a) -> {auto 0 _ : Elem b (Types a)} -> UndefOr (Nullable b)maybeToOptional : Maybe a -> Optional aoptionalToMaybe : Optional a -> Maybe aundeforToOptional : UndefOr a -> Optional aundeforToMaybe : UndefOr a -> Maybe a