Data.Undefinable

data Undefinable :: Type -> Type

This type constructor defines a representation for a value that may or may not be undefined.

Instances

• (Show a) => Show (Undefinable a)
• (Eq a) => Eq (Undefinable a)
• (Ord a) => Ord (Undefinable a)

toMaybe :: forall value. Undefinable value -> Maybe value

Takes undefined to Nothing and a value to Just value.

toUndefinable :: forall value. Maybe value -> Undefinable value

Takes Nothing to undefined and Just value to value.