562684b · streamly · git.iko.soy

git.iko.soy/streamly

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Add demux with a default when no handler matches

562684bHarendra Kumar7 years ago

src/Streamly/Internal/Data/Fold.hs+33

compare with master

unifiedsplit

@@ -159,7 +159,9 @@ module Streamly.Internal.Data.Fold

159 , demux

160 -- , demuxWith

161 , demux_

162+ , demuxDefault_

162 -- , demuxWith_

163 -- , demuxWith_

164+ , demuxWithDefault_

163

165

164 -- * Classifying

166 -- * Classifying

165

167

@@ -1016,6 +1018,32 @@ demux :: (Monad m, Ord k)

1016 => Map k (Fold m a b) -> Fold m (k, a) (Map k b)

1018 => Map k (Fold m a b) -> Fold m (k, a) (Map k b)

1017demux = demuxWith id

1019demux = demuxWith id

1018

1020

1021+{-# INLINE demuxWithDefault_ #-}

1022+demuxWithDefault_ :: (Monad m, Ord k)

1023+ => (a -> (k, a')) -> Map k (Fold m a' b) -> Fold m (k, a') b -> Fold m a ()

1024+demuxWithDefault_ f kv (Fold dstep dinitial dextract) =

1025+ Fold step initial extract

1026+

1027+ where

1028+

1029+ initFold (Fold s i e) = i >>= \r -> return (Fold s (return r) e)

1030+ initial = do

1031+ mp <- Prelude.mapM initFold kv

1032+ dacc <- dinitial

1033+ return (Tuple' mp dacc)

1034+ step (Tuple' mp dacc) a

1035+ | (k, a') <- f a

1036+ = case Map.lookup k mp of

1037+ Nothing -> do

1038+ acc <- dstep dacc (k, a')

1039+ return (Tuple' mp acc)

1040+ Just (Fold step' acc _) -> do

1041+ _ <- acc >>= \x -> step' x a'

1042+ return (Tuple' mp dacc)

1043+ extract (Tuple' mp dacc) = do

1044+ void $ dextract dacc

1045+ Prelude.mapM_ (\(Fold _ acc e) -> acc >>= e) mp

1046+

1019-- | Split the input stream based on a key field and fold each split using a

1047-- | Split the input stream based on a key field and fold each split using a

1020-- specific fold without collecting the results. Useful for cases like protocol

1048-- specific fold without collecting the results. Useful for cases like protocol

1021-- handlers to handle different type of packets.

1049-- handlers to handle different type of packets.

@@ -1074,6 +1102,11 @@ demuxWith_ f kv = Fold step initial extract

1074demux_ :: (Monad m, Ord k) => Map k (Fold m a ()) -> Fold m (k, a) ()

1102demux_ :: (Monad m, Ord k) => Map k (Fold m a ()) -> Fold m (k, a) ()

1075demux_ = demuxWith_ id

1103demux_ = demuxWith_ id

1076

1104

1105+{-# INLINE demuxDefault_ #-}

1106+demuxDefault_ :: (Monad m, Ord k)

1107+ => Map k (Fold m a ()) -> Fold m (k, a) () -> Fold m (k, a) ()

1108+demuxDefault_ = demuxWithDefault_ id

1109+

1077-- TODO If the data is large we may need a map/hashmap in pinned memory instead

1110-- TODO If the data is large we may need a map/hashmap in pinned memory instead

1078-- of a regular Map. That may require a serializable constraint though. We can

1111-- of a regular Map. That may require a serializable constraint though. We can

1079-- have another API for that.

1112-- have another API for that.