witherable 0.1.2 → 0.1.2.1

raw patch · 2 files changed

+18/−7 lines, 2 files

Files

• src/Data/Witherable.hs +17/−6
• witherable.cabal +1/−1

@@ -31,19 +31,19 @@ 
 -- | Like `traverse`, but you can remove elements instead of updating them.
 --
--- @traverse f ≡ wither (fmap Just . f)@
+-- @'traverse' f ≡ 'wither' ('fmap' 'Just' . f)@
 --
 -- A definition of 'wither' must satisfy the following laws:
 --
 -- [/identity/]
---   @wither (pure . Just) ≡ pure@
+--   @'wither' ('pure' . Just) ≡ 'pure'@
 --
 -- [/composition/]
---   @Compose . fmap (wither f) . wither g ≡ wither (Compose . fmap (maybe (pure Nothing) f) . g)@
+--   @Compose . fmap ('wither' f) . 'wither' g ≡ 'wither' (Compose . fmap ('wither' f) . g)@
 --
 -- Parametricity implies the naturality law:
 --
--- @t . wither f = wither (t . f)@
+--   @t . 'wither' f = 'wither' (t . f)@
 --
 -- Minimal complete definition: `wither` or `catMaybes`.
 -- The default definitions can be overriden for efficiency.
@@ -52,17 +52,24 @@   wither :: Applicative f => (a -> f (Maybe b)) -> t a -> f (t b)
   wither f = fmap catMaybes . T.traverse f
 
+  mapMaybe :: (a -> Maybe b) -> t a -> t b
+  mapMaybe f = runIdentity . wither (Identity . f)
+  {-# INLINE mapMaybe #-}
+
   catMaybes :: t (Maybe a) -> t a
-  catMaybes = runIdentity . wither pure
+  catMaybes = mapMaybe id
+  {-# INLINE catMaybes #-}
 
   filterA :: Applicative f => (a -> f Bool) -> t a -> f (t a)
   filterA f = wither (\a -> (\b -> if b then Just a else Nothing) <$> f a)
 
   filter :: (a -> Bool) -> t a -> t a
   filter f = runIdentity . filterA (Identity . f)
+  {-# INLINE filter #-}
 
 witherM :: (Witherable t, Monad m) => (a -> MaybeT m b) -> t a -> m (t b)
 witherM f = unwrapMonad . wither (WrapMonad . runMaybeT . f)
+{-# INLINE witherM #-}
 
 -- | 'blightM' is 'witherM' with its arguments flipped.
 blightM :: (Monad m, Witherable t) => t a -> (a -> MaybeT m b) -> m (t b)
@@ -90,12 +97,16 @@ instance Witherable IM.IntMap where
   wither f = fmap IM.fromAscList . wither (\(i, a) -> fmap ((,) i) <$> f a) . IM.toList
   {-# INLINABLE wither #-}
+  mapMaybe = IM.mapMaybe
+  {-# INLINE mapMaybe #-}
   filter = IM.filter
-  {-# INLINABLE filter #-}
+  {-# INLINE filter #-}
 
 instance Ord k => Witherable (M.Map k) where
   wither f = fmap M.fromAscList . wither (\(i, a) -> fmap ((,) i) <$> f a) . M.toList
   {-# INLINABLE wither #-}
+  mapMaybe = M.mapMaybe
+  {-# INLINE mapMaybe #-}
   filter = M.filter
   {-# INLINABLE filter #-}
 

@@ -1,5 +1,5 @@ name:                witherable
-version:             0.1.2
+version:             0.1.2.1
 synopsis:            Generalization of filter and catMaybes
 -- description:
 homepage:            https://github.com/fumieval/witherable