Data.Unrestricted.Linear.Internal.Movable

Use Movable a to represent a type which can be used many times even when given linearly. Simple data types such as Bool or [] are Movable. Though, bear in mind that this typically induces a deep copy of the value.

Formally, Movable a is the class of coalgebras of the Ur comonad. That is

• unur (move x) = x

• move @(Ur a) (move @a x) = fmap (move @a) $ move @a x

Additionally, a Movable instance must be compatible with its Dupable parent instance. That is:

• case move x of {Ur _ -> ()} = consume x

• case move x of {Ur x -> (x, x)} = dup2 x