profunctors 5.0.1 → 5.1

raw patch · 5 files changed

+58/−6 lines, 5 files

Files

• CHANGELOG.markdown +6/−0
• profunctors.cabal +1/−1
• src/Data/Profunctor.hs +34/−3
• src/Data/Profunctor/Composition.hs +4/−0
• src/Data/Profunctor/Rep.hs +13/−2

@@ -1,3 +1,9 @@+5.1+---+* `instance Costrong (Cokleisli f)`.+* `instance Cochoice (Star f)`.+* Changed the instance for `Cochoice (Costar f)`.+ 5.0.1 ----- * MINIMAL pragma for `Costrong` and `Cochoice`.

@@ -1,6 +1,6 @@ name:          profunctors category:      Control, Categories-version:       5.0.1+version:       5.1 license:       BSD3 cabal-version: >= 1.10 license-file:  LICENSE

@@ -301,7 +301,7 @@ -- | The generalization of 'Costar' of 'Functor' that is strong with respect -- to 'Either'. ----- Note: This is also a notion of strength, except with regards to another monoidal +-- Note: This is also a notion of strength, except with regards to another monoidal -- structure that we can choose to equip Hask with: the cocartesian coproduct. class Profunctor p => Choice p where   left'  :: p a b -> p (Either a c) (Either b c)@@ -328,9 +328,9 @@   {-# INLINE right' #-}  instance Applicative f => Choice (Star f) where-  left' (Star f) = Star $ either (fmap Left . f) (fmap Right . pure)+  left' (Star f) = Star $ either (fmap Left . f) (pure . Right)   {-# INLINE left' #-}-  right' (Star f) = Star $ either (fmap Left . pure) (fmap Right . f)+  right' (Star f) = Star $ either (pure . Left) (fmap Right . f)   {-# INLINE right' #-}  -- | 'extract' approximates 'costrength'@@ -377,10 +377,20 @@   unsecond :: p (d, a) (d, b) -> p a b   unsecond = unfirst . dimap swap swap +#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 708+  {-# MINIMAL unfirst | unsecond #-}+#endif+ instance Costrong (->) where   unfirst f a = b where (b, d) = f (a, d)   unsecond f a = b where (d, b) = f (d, a) +instance Functor f => Costrong (Costar f) where+  unfirst (Costar f) = Costar f'+    where f' fa = b where (b, d) = f ((\a -> (a, d)) <$> fa)+  unsecond (Costar f) = Costar f'+    where f' fa = b where (d, b) = f ((,) d <$> fa)+ instance Costrong Tagged where   unfirst (Tagged bd) = Tagged (fst bd)   unsecond (Tagged db) = Tagged (snd db)@@ -392,6 +402,10 @@   unfirst (Kleisli f) = Kleisli (liftM fst . mfix . f')     where f' x y = f (x, snd y) +instance Functor f => Costrong (Cokleisli f) where+  unfirst (Cokleisli f) = Cokleisli f'+    where f' fa = b where (b, d) = f ((\a -> (a, d)) <$> fa)+ -------------------------------------------------------------------------------- -- * Costrength for Either --------------------------------------------------------------------------------@@ -402,3 +416,20 @@    unright :: p (Either d a) (Either d b) -> p a b   unright = unleft . dimap (either Right Left) (either Right Left)++#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ >= 708+  {-# MINIMAL unleft | unright #-}+#endif++instance Cochoice (->) where+  unleft f = go . Left where go = either id (go . Right) . f+  unright f = go . Right where go = either (go . Left) id . f++instance Applicative f => Cochoice (Costar f) where+  unleft (Costar f) = Costar (go . fmap Left)+    where go = either id (go . pure . Right) . f++-- NB: Another instance that's highly questionable+instance Traversable f => Cochoice (Star f) where+  unright (Star f) = Star (go . Right)+    where go = either (go . Left) id . sequence . f

@@ -127,6 +127,10 @@   closed (Procompose x y) = Procompose (closed x) (closed y)   {-# INLINE closed #-} +instance (Corepresentable p, Corepresentable q) => Costrong (Procompose p q) where+  unfirst = unfirstCorep+  unsecond = unsecondCorep+ -- * Lax identity  -- | @(->)@ functions as a lax identity for 'Profunctor' composition.

@@ -27,6 +27,7 @@   -- * Corepresentable Profunctors   , Corepresentable(..)   , cotabulated+  , unfirstCorep, unsecondCorep   ) where  import Control.Applicative@@ -68,7 +69,7 @@   type Rep (Star f) = f   tabulate = Star   {-# INLINE tabulate #-}-  + instance Representable (Forget r) where   type Rep (Forget r) = Const r   tabulate = Forget . (getConst .)@@ -89,9 +90,19 @@  -- | A 'Profunctor' @p@ is 'Corepresentable' if there exists a 'Functor' @f@ such that -- @p d c@ is isomorphic to @f d -> c@.-class Cosieve p (Corep p) => Corepresentable p where+class (Cosieve p (Corep p), Costrong p) => Corepresentable p where   type Corep p :: * -> *   cotabulate :: (Corep p d -> c) -> p d c++-- | Default definition for 'unfirst' given that p is 'Corepresentable'.+unfirstCorep :: Corepresentable p => p (a, d) (b, d) -> p a b+unfirstCorep p = cotabulate f+  where f fa = b where (b, d) = cosieve p ((\a -> (a, d)) <$> fa)++-- | Default definition for 'unsecond' given that p is 'Corepresentable'.+unsecondCorep :: Corepresentable p => p (d, a) (d, b) -> p a b+unsecondCorep p = cotabulate f+  where f fa = b where (d, b) = cosieve p ((,) d <$> fa)  instance Corepresentable (->) where   type Corep (->) = Identity