Copyright	(C) 2007-2015 Edward Kmett
License	BSD-style (see the file LICENSE)
Maintainer	Edward Kmett <ekmett@gmail.com>
Stability	experimental
Portability	ConstraintKinds
Safe Haskell	Trustworthy
Language	Haskell98

Data.Functor.Contravariant.Generic

Description

Synopsis

Documentation

class (Generic a, GDeciding q (Rep a)) => Deciding q a where

This provides machinery for deconstructing an arbitrary Generic instance using a Decidable Contravariant functor.

Examples:

gcompare :: Deciding Ord a => a -> a -> Ordering
gcompare = getComparison $ deciding (Proxy :: Proxy Ord) (Comparison compare)

geq :: Deciding Eq a => a -> a -> Bool
geq = getEquivalence $ deciding (Proxy :: Proxy Eq) (Equivalence (==))

Methods

deciding :: Decidable f => p q -> (forall b. q b => f b) -> f a

Instances

(Generic a, GDeciding * q (Rep a)) => Deciding q a

class (Generic1 t, GDeciding1 q (Rep1 t)) => Deciding1 q t where

This provides machinery for deconstructing an arbitrary Generic1 instance using a Decidable Contravariant functor.

Examples:

gcompare1 :: Deciding1 Ord f => (a -> a -> Ordering) -> f a -> f a -> Ordering
gcompare1 f = getComparison $ deciding1 (Proxy :: Proxy Ord) (Comparison compare) (Comparison f)

geq1 :: Deciding1 Eq f => (a -> a -> Bool) -> f a -> f a -> Bool
geq1 f = getEquivalence $ deciding1 (Proxy :: Proxy Eq) (Equivalence (==)) (Equivalence f)

Methods

deciding1 :: Decidable f => p q -> (forall b. q b => f b) -> f a -> f (t a)

Instances

(Generic1 t, GDeciding1 q (Rep1 t)) => Deciding1 q t