Yaya.Unsafe.Zoo

Documentation

chrono :: Functor f => GAlgebra (Cofree f) f b -> GCoalgebra (Free f) f a -> a -> b

codyna :: Functor f => Algebra f b -> GCoalgebra (Free f) f a -> a -> b

dyna :: Functor f => GAlgebra (Cofree f) f b -> Coalgebra f a -> a -> b

Recursion Schemes for Dynamic Programming

elgot :: Functor f => Algebra f b -> ElgotCoalgebra (Either b) f a -> a -> b

Unlike most hylos, elgot composes an algebra and coalgebra in a way that allows information to move between them. The coalgebra can return, effectively, a pre-folded branch, short-circuiting parts of the process.

coelgot :: Functor f => ElgotAlgebra ((,) a) f b -> Coalgebra f a -> a -> b

The dual of elgot, coelgot allows the _algebra_ to short-circuit in some cases – operating directly on a part of the seed.

futu :: (Corecursive t f, Functor f) => GCoalgebra (Free f) f a -> a -> t

gprepro :: (Steppable t f, Recursive t f, Functor f, Comonad w) => DistributiveLaw f w -> GAlgebra w f a -> (forall a. f a -> f a) -> t -> a

gpostpro :: (Steppable t f, Corecursive t f, Functor f, Monad m) => DistributiveLaw m f -> (forall a. f a -> f a) -> GCoalgebra m f a -> a -> t

stream :: Coalgebra (XNor c) b -> (b -> a -> b) -> b -> [a] -> [c]

The metamorphism definition from Gibbons’ paper.

fstream :: Coalgebra (XNor c) b -> (b -> a -> b) -> Coalgebra (XNor c) b -> b -> [a] -> [c]

Basically the definition from Gibbons’ paper, except the flusher (h) is a Coalgebra instead of an unfold.

cotraverse :: (Steppable t (f a), Steppable u (f b), Corecursive u (f b), Bitraversable f, Traversable (f b), Monad m) => (a -> m b) -> t -> m u

zygoHistoPrepro :: (Steppable t f, Recursive t f, Functor f) => (f b -> b) -> (f (EnvT b (Cofree f) a) -> a) -> (forall c. f c -> f c) -> t -> a

Zygohistomorphic prepromorphism – everyone’s favorite recursion scheme joke.