contravariant 0.1.2.1 → 0.1.3

raw patch · 2 files changed

+29/−21 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• Data/Functor/Contravariant.hs +28/−20
• contravariant.cabal +1/−1

@@ -13,10 +13,13 @@ -- the definition of 'Contravariant' for a given ADT is unambiguous. ---------------------------------------------------------------------------- -module Data.Functor.Contravariant ( +module Data.Functor.Contravariant (   -- * Contravariant Functors     Contravariant(..)-  ++  -- * Operators+  , (>$<), (>$$<)+   -- * Predicates   , Predicate(..) @@ -27,7 +30,7 @@   -- * Equivalence Relations   , Equivalence(..)   , defaultEquivalence-  +   -- * Dual arrows   , Op(..)   ) where@@ -41,28 +44,35 @@ -- > contramap id = id -- > contramap f . contramap g = contramap (g . f) ----- Note, that the second law follows from the free theorem of the type of --- 'contramap' and the first law, so you need only check that the former +-- Note, that the second law follows from the free theorem of the type of+-- 'contramap' and the first law, so you need only check that the former -- condition holds.  class Contravariant f where-  contramap :: (a -> b) -> f b -> f a +  contramap :: (a -> b) -> f b -> f a +infixl 4 >$<, >$$< +(>$<) :: Contravariant f => (a -> b) -> f b -> f a+(>$<) = contramap+{-# INLINE (>$<) #-} -newtype Predicate a = Predicate { getPredicate :: a -> Bool } --- | A 'Predicate' is a 'Contravariant' 'Functor', because 'contramap' can +(>$$<) :: Contravariant f => f b -> (a -> b) -> f a+(>$$<) = flip contramap+{-# INLINE (>$$<) #-}++newtype Predicate a = Predicate { getPredicate :: a -> Bool }++-- | A 'Predicate' is a 'Contravariant' 'Functor', because 'contramap' can -- apply its function argument to the input of the predicate. instance Contravariant Predicate where   contramap f g = Predicate $ getPredicate g . f -- -- | Defines a total ordering on a type as per 'compare'-newtype Comparison a = Comparison { getComparison :: a -> a -> Ordering } +newtype Comparison a = Comparison { getComparison :: a -> a -> Ordering } --- | A 'Comparison' is a 'Contravariant' 'Functor', because 'contramap' can --- apply its function argument to each input to each input to the +-- | A 'Comparison' is a 'Contravariant' 'Functor', because 'contramap' can+-- apply its function argument to each input to each input to the -- comparison function. instance Contravariant Comparison where   contramap f g = Comparison $ \a b -> getComparison g (f a) (f b)@@ -71,12 +81,10 @@ defaultComparison :: Ord a => Comparison a defaultComparison = Comparison compare ----- | Define an equivalence relation -newtype Equivalence a = Equivalence { getEquivalence :: a -> a -> Bool } --- | Equivalence relations are 'Contravariant', because you can --- apply the contramapped function to each input to the equivalence +-- | Define an equivalence relation+newtype Equivalence a = Equivalence { getEquivalence :: a -> a -> Bool }+-- | Equivalence relations are 'Contravariant', because you can+-- apply the contramapped function to each input to the equivalence -- relation. instance Contravariant Equivalence where   contramap f g = Equivalence $ \a b -> getEquivalence g (f a) (f b)@@ -86,7 +94,7 @@ defaultEquivalence = Equivalence (==)  -- | Dual function arrows.-newtype Op a b = Op { getOp :: b -> a } +newtype Op a b = Op { getOp :: b -> a }  instance Contravariant (Op a) where   contramap f g = Op (getOp g . f)

@@ -1,6 +1,6 @@ name:          contravariant category:      Control, Data-version:       0.1.2.1+version:       0.1.3 license:       BSD3 cabal-version: >= 1.6 license-file:  LICENSE