Data.Functor.Mu

newtype Mu :: (Type -> Type) -> Typenewtype Mu f

Mu f is the least fixed point of a functor f, when it exists.

Constructors

• In (f (Mu f))

Instances

• Newtype (Mu f) _
• (Eq1 f) => Eq (Mu f)

  To implement Eq, we require f to have higher-kinded equality.

• (Eq1 f, Ord1 f) => Ord (Mu f)

  To implement Ord, we require f to have higher-kinded comparison.

• (Show (f TacitString), Functor f) => Show (Mu f)

  Show is compositional, so we only f to be able to show a single layer of structure.

• (Alt f) => Semigroup (Mu f)
• (Plus f) => Monoid (Mu f)

roll :: forall f. f (Mu f) -> Mu f

unroll :: forall f. Mu f -> f (Mu f)

transMu :: forall f g. Functor g => f ~> g -> Mu f -> Mu g

Rewrites a tree along a natural transformation.