Data.Fixpoint

Documentation

class Functor (Pre t) => Fixpoint t where

The class of data types representable by fixpoints.

Associated Types

data Pre t :: * -> *

Methods

project :: t -> Pre t t

Projection from the data type to its underlying functor.

inject :: Pre t t -> t

Injection from the underlying functor into the data type.

Instances

Fixpoint [a]

cata :: Fixpoint t => (Pre t s -> s) -> t -> s

Catamorphism (same as fold)

fold :: Fixpoint t => (Pre t s -> s) -> t -> s

Catamorphism (same as cata)

ana :: Fixpoint t => (s -> Pre t s) -> s -> t

Anamorphism (same as unfold)

unfold :: Fixpoint t => (s -> Pre t s) -> s -> t

Anamorphism (same as ana)

hylo :: Fixpoint t => (Pre t s -> s) -> (p -> Pre t p) -> p -> s

Hylomorphism

para :: Fixpoint t => (Pre t (t, s) -> s) -> t -> s

Paramorphism