34770c4 · streamly · git.iko.soy

git.iko.soy/streamly

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Add a Functor instance for Producer

34770c4Harendra Kumar6 years ago

src/Streamly/Internal/Data/Producer/Type.hs+22−1

@@ -34,7 +34,7 @@ where

35import Fusion.Plugin.Types (Fuse(..))

36import Streamly.Internal.Data.Stream.StreamD.Step (Step(..))

37−import Prelude hiding (concat)

37+import Prelude hiding (concat, map)

39------------------------------------------------------------------------------

40-- Type

@@ -112,6 +112,27 @@ translate f g (Producer step inject extract) =

112lmap :: (a -> a) -> Producer m a b -> Producer m a b

113lmap f (Producer step inject extract) = Producer step (inject . f) extract

114

115+------------------------------------------------------------------------------

116+-- Functor

117+------------------------------------------------------------------------------

118+

119+-- | Map a function on the output of the producer (the type @b@).

120+--

121+-- /Internal/

122+{-# INLINE_NORMAL map #-}

123+map :: Functor m => (b -> c) -> Producer m a b -> Producer m a c

124+map f (Producer ustep uinject uextract) = Producer step uinject uextract

125+

126+ where

127+

128+ {-# INLINE_LATE step #-}

129+ step st = fmap (fmap f) (ustep st)

130+

131+-- | Maps a function on the output of the producer (the type @b@).

132+instance Functor m => Functor (Producer m a) where

133+ {-# INLINE fmap #-}

134+ fmap = map

135+

115------------------------------------------------------------------------------

136------------------------------------------------------------------------------

116-- Nesting

137-- Nesting

117------------------------------------------------------------------------------

138------------------------------------------------------------------------------