Zip.hs

{-# LANGUAGE CPP                       #-}
{-# LANGUAGE ConstraintKinds           #-}
{-# LANGUAGE FlexibleContexts          #-}
{-# LANGUAGE FlexibleInstances         #-}
{-# LANGUAGE GeneralizedNewtypeDeriving#-}
{-# LANGUAGE InstanceSigs              #-}
{-# LANGUAGE MultiParamTypeClasses     #-}
{-# LANGUAGE TypeFamilies              #-}
{-# LANGUAGE UndecidableInstances      #-} -- XXX

#if MIN_VERSION_base(4,17,0)
{-# LANGUAGE TypeOperators             #-}
#endif

-- |
-- Module      : Streamly.Internal.Data.Stream.Zip
-- Copyright   : (c) 2017 Harendra Kumar
--
-- License     : BSD3
-- Maintainer  : streamly@composewell.com
-- Stability   : experimental
-- Portability : GHC
--
--
module Streamly.Internal.Data.Stream.Zip
    (
      ZipSerialM
    , ZipSerial
    , zipSerially

    , ZipAsyncM
    , ZipAsync
    , zipAsyncly

    , zipWith
    , zipWithM
    , zipAsyncWith
    , zipAsyncWithM

    -- * Deprecated
    , ZipStream
    , zipping
    , zippingAsync
    )
where

import Control.Applicative (liftA2)
import Control.DeepSeq (NFData(..))
#if MIN_VERSION_deepseq(1,4,3)
import Control.DeepSeq (NFData1(..))
#endif
import Data.Foldable (Foldable(foldl'), fold)
import Data.Functor.Identity (Identity(..), runIdentity)
import Data.Maybe (fromMaybe)
import Data.Semigroup (Endo(..))
#if __GLASGOW_HASKELL__ < 808
import Data.Semigroup (Semigroup(..))
#endif
import GHC.Exts (IsList(..), IsString(..))
import Text.Read (Lexeme(Ident), lexP, parens, prec, readPrec, readListPrec,
                  readListPrecDefault)
import Prelude hiding (map, repeat, zipWith, errorWithoutStackTrace)

import Streamly.Internal.BaseCompat ((#.), errorWithoutStackTrace)
import Streamly.Internal.Data.Stream.StreamK (IsStream(..), Stream)
import Streamly.Internal.Data.Strict (Maybe'(..), toMaybe)
import Streamly.Internal.Data.SVar (MonadAsync)

import qualified Streamly.Internal.Data.Stream.Prelude as P
import qualified Streamly.Internal.Data.Stream.StreamK as K
import qualified Streamly.Internal.Data.Stream.StreamD as D

#ifdef USE_STREAMK_ONLY
import qualified Streamly.Internal.Data.Stream.StreamK as S
#else
import qualified Streamly.Internal.Data.Stream.StreamD as S
#endif

#include "Instances.hs"

-- | Like 'zipWith' but using a monadic zipping function.
--
-- @since 0.4.0
{-# INLINABLE zipWithM #-}
zipWithM :: (IsStream t, Monad m) => (a -> b -> m c) -> t m a -> t m b -> t m c
zipWithM f m1 m2 = P.fromStreamS $ S.zipWithM f (P.toStreamS m1) (P.toStreamS m2)

-- | Zip two streams serially using a pure zipping function.
--
-- @
-- > S.toList $ S.zipWith (+) (S.fromList [1,2,3]) (S.fromList [4,5,6])
-- [5,7,9]
-- @
--
-- @since 0.1.0
{-# INLINABLE zipWith #-}
zipWith :: (IsStream t, Monad m) => (a -> b -> c) -> t m a -> t m b -> t m c
zipWith f m1 m2 = P.fromStreamS $ S.zipWith f (P.toStreamS m1) (P.toStreamS m2)

------------------------------------------------------------------------------
-- Parallel Zipping
------------------------------------------------------------------------------

-- | Like 'zipWithM' but zips concurrently i.e. both the streams being zipped
-- are generated concurrently.
--
-- @since 0.4.0
{-# INLINE zipAsyncWithM #-}
zipAsyncWithM :: (IsStream t, MonadAsync m)
    => (a -> b -> m c) -> t m a -> t m b -> t m c
zipAsyncWithM f m1 m2 = D.fromStreamD $
    D.zipWithM f (D.mkParallelD $ D.toStreamD m1)
                 (D.mkParallelD $ D.toStreamD m2)

-- | Like 'zipWith' but zips concurrently i.e. both the streams being zipped
-- are generated concurrently.
--
-- @since 0.1.0
{-# INLINE zipAsyncWith #-}
zipAsyncWith :: (IsStream t, MonadAsync m)
    => (a -> b -> c) -> t m a -> t m b -> t m c
zipAsyncWith f = zipAsyncWithM (\a b -> return (f a b))

------------------------------------------------------------------------------
-- Serially Zipping Streams
------------------------------------------------------------------------------

-- | The applicative instance of 'ZipSerialM' zips a number of streams serially
-- i.e. it produces one element from each stream serially and then zips all
-- those elements.
--
-- @
-- main = (toList . 'zipSerially' $ (,,) \<$\> s1 \<*\> s2 \<*\> s3) >>= print
--     where s1 = fromFoldable [1, 2]
--           s2 = fromFoldable [3, 4]
--           s3 = fromFoldable [5, 6]
-- @
-- @
-- [(1,3,5),(2,4,6)]
-- @
--
-- The 'Semigroup' instance of this type works the same way as that of
-- 'SerialT'.
--
-- @since 0.2.0
newtype ZipSerialM m a = ZipSerialM {getZipSerialM :: Stream m a}
        deriving (Semigroup, Monoid)

-- |
-- @since 0.1.0
{-# DEPRECATED ZipStream "Please use 'ZipSerialM' instead." #-}
type ZipStream = ZipSerialM

-- | An IO stream whose applicative instance zips streams serially.
--
-- @since 0.2.0
type ZipSerial = ZipSerialM IO

-- | Fix the type of a polymorphic stream as 'ZipSerialM'.
--
-- @since 0.2.0
zipSerially :: IsStream t => ZipSerialM m a -> t m a
zipSerially = K.adapt

-- | Same as 'zipSerially'.
--
-- @since 0.1.0
{-# DEPRECATED zipping "Please use zipSerially instead." #-}
zipping :: IsStream t => ZipSerialM m a -> t m a
zipping = zipSerially

consMZip :: Monad m => m a -> ZipSerialM m a -> ZipSerialM m a
consMZip m ms = fromStream $ K.consMStream m (toStream ms)

instance IsStream ZipSerialM where
    toStream = getZipSerialM
    fromStream = ZipSerialM

    {-# INLINE consM #-}
    {-# SPECIALIZE consM :: IO a -> ZipSerialM IO a -> ZipSerialM IO a #-}
    consM :: Monad m => m a -> ZipSerialM m a -> ZipSerialM m a
    consM = consMZip

    {-# INLINE (|:) #-}
    {-# SPECIALIZE (|:) :: IO a -> ZipSerialM IO a -> ZipSerialM IO a #-}
    (|:) :: Monad m => m a -> ZipSerialM m a -> ZipSerialM m a
    (|:) = consMZip

LIST_INSTANCES(ZipSerialM)
NFDATA1_INSTANCE(ZipSerialM)

instance Monad m => Functor (ZipSerialM m) where
    {-# INLINE fmap #-}
    fmap f (ZipSerialM m) = D.fromStreamD $ D.mapM (return . f) $ D.toStreamD m

instance Monad m => Applicative (ZipSerialM m) where
    pure = ZipSerialM . K.repeat
    {-# INLINE (<*>) #-}
    (<*>) = zipWith id

FOLDABLE_INSTANCE(ZipSerialM)
TRAVERSABLE_INSTANCE(ZipSerialM)

------------------------------------------------------------------------------
-- Parallely Zipping Streams
------------------------------------------------------------------------------
--
-- | Like 'ZipSerialM' but zips in parallel, it generates all the elements to
-- be zipped concurrently.
--
-- @
-- main = (toList . 'zipAsyncly' $ (,,) \<$\> s1 \<*\> s2 \<*\> s3) >>= print
--     where s1 = fromFoldable [1, 2]
--           s2 = fromFoldable [3, 4]
--           s3 = fromFoldable [5, 6]
-- @
-- @
-- [(1,3,5),(2,4,6)]
-- @
--
-- The 'Semigroup' instance of this type works the same way as that of
-- 'SerialT'.
--
-- @since 0.2.0
newtype ZipAsyncM m a = ZipAsyncM {getZipAsyncM :: Stream m a}
        deriving (Semigroup, Monoid)

-- | An IO stream whose applicative instance zips streams wAsyncly.
--
-- @since 0.2.0
type ZipAsync = ZipAsyncM IO

-- | Fix the type of a polymorphic stream as 'ZipAsyncM'.
--
-- @since 0.2.0
zipAsyncly :: IsStream t => ZipAsyncM m a -> t m a
zipAsyncly = K.adapt

-- | Same as 'zipAsyncly'.
--
-- @since 0.1.0
{-# DEPRECATED zippingAsync "Please use zipAsyncly instead." #-}
zippingAsync :: IsStream t => ZipAsyncM m a -> t m a
zippingAsync = zipAsyncly

consMZipAsync :: Monad m => m a -> ZipAsyncM m a -> ZipAsyncM m a
consMZipAsync m ms = fromStream $ K.consMStream m (toStream ms)

instance IsStream ZipAsyncM where
    toStream = getZipAsyncM
    fromStream = ZipAsyncM

    {-# INLINE consM #-}
    {-# SPECIALIZE consM :: IO a -> ZipAsyncM IO a -> ZipAsyncM IO a #-}
    consM :: Monad m => m a -> ZipAsyncM m a -> ZipAsyncM m a
    consM = consMZipAsync

    {-# INLINE (|:) #-}
    {-# SPECIALIZE (|:) :: IO a -> ZipAsyncM IO a -> ZipAsyncM IO a #-}
    (|:) :: Monad m => m a -> ZipAsyncM m a -> ZipAsyncM m a
    (|:) = consMZipAsync

instance Monad m => Functor (ZipAsyncM m) where
    {-# INLINE fmap #-}
    fmap f (ZipAsyncM m) = D.fromStreamD $ D.mapM (return . f) $ D.toStreamD m

instance MonadAsync m => Applicative (ZipAsyncM m) where
    pure = ZipAsyncM . K.repeat
    {-# INLINE (<*>) #-}
    m1 <*> m2 = zipAsyncWith id m1 m2