Moduleselective-0.7.0.1Haskell2010

Control.Selective.Free

This is a library for selective applicative functors, or just selective functors for short, an abstraction between applicative functors and monads, introduced in this paper: https://dl.acm.org/doi/10.1145/3341694.

This module defines free selective functors using the ideas from the Sjoerd Visscher's package 'free-functors': https://hackage.haskell.org/package/free-functors-1.0.1/docs/Data-Functor-HFree.html.

1 type
6 values

Packageselective-0.7.0.1
Exports7
LanguageHaskell2010
LicenceMIT
SourceFree.hs

Free selective functors

2 declarations

newtypenewtype Select (f :: Type -> Type) a

Free selective functors.

Constructors

Select (forall (g :: Type -> Type). Selective g => (forall x. f x -> g x) -> g a)

Instances3Functor, Applicative, Selective

Functor (Select f)Defined in selective-0.7.0.1 · Control.Selective.Free
Applicative (Select f)Defined in selective-0.7.0.1 · Control.Selective.Free
Selective (Select f)Defined in selective-0.7.0.1 · Control.Selective.Free

valueliftSelect :: f a -> Select f a

Lift a functor into a free selective computation.

Static analysis

5 declarations

valuegetPure :: Select f a -> Maybe a

Extract the resulting value if there are no necessary effects.

valuegetEffects :: Functor f => Select f a -> [f ()]

Collect all possible effects in the order they appear in a free selective computation.

valuegetNecessaryEffects :: Functor f => Select f a -> [f ()]

Extract all necessary effects in the order they appear in a free selective computation.

valuerunSelect :: Selective g => (forall x. f x -> g x) -> Select f a -> g a

Given a natural transformation from f to g, this gives a canonical natural transformation from Select f to g. Note that here we rely on the fact that g is a lawful selective functor.

valuefoldSelect :: Monoid m => (forall x. f x -> m) -> Select f a -> m

Concatenate all effects of a free selective computation.