Control.Functor.Algebra.Elgot

Elgot algebras, and their obvious dual, based on: http://www.iti.cs.tu-bs.de/~milius/research/elgot_lmcs.pdf

Elgot algebras given you a shortcircuitable hylomorphism where you can directly return a sub-answer to the catamorphism.

Elgot coalgebras are defined in: http://comonad.com/reader/2008/elgot-coalgebras/

Documentation

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

Elgot algebra

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

Elgot coalgebra