Copyright	(C) 2012 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	provisional
Portability	GADTs, Rank2Types
Safe Haskell	Safe
Language	Haskell2010

Control.Alternative.Free

Description

Left distributive Alternative functors for free, based on a design by Stijn van Drongelen.

Synopsis

Documentation

newtype Alt f a Source

Constructors

Alt
Fields alternatives :: [AltF f a]

Instances

Functor f => Functor (Alt f) Source
Functor f => Applicative (Alt f) Source
Functor f => Alternative (Alt f) Source
Functor f => Alt (Alt f) Source
Functor f => Apply (Alt f) Source
Functor f => Monoid (Alt f a) Source
Functor f => Semigroup (Alt f a) Source

data AltF f a where Source

Constructors

Ap :: f a -> Alt f (a -> b) -> AltF f b infixl 3
Pure :: a -> AltF f a

Instances

Functor f => Functor (AltF f) Source
Functor f => Applicative (AltF f) Source

runAlt :: forall f g a. Alternative g => (forall x. f x -> g x) -> Alt f a -> g a Source

Given a natural transformation from f to g, this gives a canonical monoidal natural transformation from Alt f to g.

A version of lift that can be used with just a Functor for f.

hoistAlt :: (forall a. f a -> g a) -> Alt f b -> Alt g b Source

Given a natural transformation from f to g this gives a monoidal natural transformation from Alt f to Alt g.