Data.Algebra.Internal

Documentation

class Functor f => AlgebraSignature f where

Associated Types

type Class f :: * -> Constraint

The class for which f is the signature.

Methods

evaluate :: Class f b => f b -> b

Translate the operations of the signature to method calls of the class.

Instances

AlgebraSignature MonoidSignature

class Algebra f a where

Methods

algebra :: AlgebraSignature f => f a -> a

An algebra f a -> a corresponds to an instance of a of the class Class f. In some cases, for example for tuple types, you can give an algebra generically for every signature:

 instance (Class f m, Class f n) => Algebra f (m, n) where
   algebra fmn = (evaluate (fmap fst fmn), evaluate (fmap snd fmn))

Instances

Algebra f ()

Class f b => Algebra f (a -> b)

(Class f m, Class f n) => Algebra f (m, n)