{-# LANGUAGE UndecidableInstances #-}

-- |
-- Module      : Streamly.Internal.Data.Stream.Serial
-- Copyright   : (c) 2017 Composewell Technologies
--
-- License     : BSD3
-- Maintainer  : streamly@composewell.com
-- Stability   : experimental
-- Portability : GHC
--
-- To run examples in this module:
--
-- >>> import qualified Streamly.Prelude as Stream
--
module Streamly.Internal.Data.Stream.Serial
    (
    -- * Serial appending stream
      SerialT(..)
    , Serial
    , serial

    -- * Serial interleaving stream
    , WSerialT(..)
    , WSerial
    , wSerialK
    , wSerial
    , wSerialFst
    , wSerialMin
    , consMWSerial

    -- * Construction
    , cons
    , consM
    , repeat
    , unfoldrM
    , fromList

    -- * Elimination
    , toList

    -- * Transformation
    , map
    , mapM

    -- * Deprecated
    , StreamT
    , InterleavedT
    )
where

import Control.Applicative (liftA2)
import Control.DeepSeq (NFData(..))
#if MIN_VERSION_deepseq(1,4,3)
import Control.DeepSeq (NFData1(..))
#endif
import Control.Monad.Base (MonadBase(..), liftBaseDefault)
import Control.Monad.Catch (MonadThrow, throwM)
import Control.Monad.IO.Class (MonadIO(..))
import Control.Monad.Reader.Class (MonadReader(..))
import Control.Monad.State.Class (MonadState(..))
import Control.Monad.Trans.Class (MonadTrans(lift))
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 Streamly.Internal.BaseCompat ((#.), errorWithoutStackTrace, oneShot)
import Streamly.Internal.Data.Maybe.Strict (Maybe'(..), toMaybe)
import Streamly.Internal.Data.Stream.StreamK.Type
       (Stream, mkStream, foldStream)

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

import Prelude hiding (map, mapM, errorWithoutStackTrace, repeat)

#include "Instances.hs"
#include "inline.hs"

-- $setup
-- >>> import qualified Streamly.Prelude as Stream

------------------------------------------------------------------------------
-- SerialT
------------------------------------------------------------------------------

-- | For 'SerialT' streams:
--
-- @
-- (<>) = 'Streamly.Prelude.serial'                       -- 'Semigroup'
-- (>>=) = flip . 'Streamly.Prelude.concatMapWith' 'Streamly.Prelude.serial' -- 'Monad'
-- @
--
-- A single 'Monad' bind behaves like a @for@ loop:
--
-- >>> :{
-- Stream.toList $ do
--      x <- Stream.fromList [1,2] -- foreach x in stream
--      return x
-- :}
-- [1,2]
--
-- Nested monad binds behave like nested @for@ loops:
--
-- >>> :{
-- Stream.toList $ do
--     x <- Stream.fromList [1,2] -- foreach x in stream
--     y <- Stream.fromList [3,4] -- foreach y in stream
--     return (x, y)
-- :}
-- [(1,3),(1,4),(2,3),(2,4)]
--
-- /Since: 0.2.0 ("Streamly")/
--
-- @since 0.8.0
newtype SerialT m a = SerialT {forall (m :: * -> *) a. SerialT m a -> Stream m a
getSerialT :: Stream m a}
    -- XXX when deriving do we inherit an INLINE?
    deriving (NonEmpty (SerialT m a) -> SerialT m a
SerialT m a -> SerialT m a -> SerialT m a
forall b. Integral b => b -> SerialT m a -> SerialT m a
forall a.
(a -> a -> a)
-> (NonEmpty a -> a)
-> (forall b. Integral b => b -> a -> a)
-> Semigroup a
forall (m :: * -> *) a. NonEmpty (SerialT m a) -> SerialT m a
forall (m :: * -> *) a. SerialT m a -> SerialT m a -> SerialT m a
forall (m :: * -> *) a b.
Integral b =>
b -> SerialT m a -> SerialT m a
stimes :: forall b. Integral b => b -> SerialT m a -> SerialT m a
$cstimes :: forall (m :: * -> *) a b.
Integral b =>
b -> SerialT m a -> SerialT m a
sconcat :: NonEmpty (SerialT m a) -> SerialT m a
$csconcat :: forall (m :: * -> *) a. NonEmpty (SerialT m a) -> SerialT m a
<> :: SerialT m a -> SerialT m a -> SerialT m a
$c<> :: forall (m :: * -> *) a. SerialT m a -> SerialT m a -> SerialT m a
Semigroup, SerialT m a
[SerialT m a] -> SerialT m a
SerialT m a -> SerialT m a -> SerialT m a
forall a.
Semigroup a -> a -> (a -> a -> a) -> ([a] -> a) -> Monoid a
forall (m :: * -> *) a. Semigroup (SerialT m a)
forall (m :: * -> *) a. SerialT m a
forall (m :: * -> *) a. [SerialT m a] -> SerialT m a
forall (m :: * -> *) a. SerialT m a -> SerialT m a -> SerialT m a
mconcat :: [SerialT m a] -> SerialT m a
$cmconcat :: forall (m :: * -> *) a. [SerialT m a] -> SerialT m a
mappend :: SerialT m a -> SerialT m a -> SerialT m a
$cmappend :: forall (m :: * -> *) a. SerialT m a -> SerialT m a -> SerialT m a
mempty :: SerialT m a
$cmempty :: forall (m :: * -> *) a. SerialT m a
Monoid, forall (m :: * -> *) a. Monad m => m a -> SerialT m a
forall (t :: (* -> *) -> * -> *).
(forall (m :: * -> *) a. Monad m => m a -> t m a) -> MonadTrans t
lift :: forall (m :: * -> *) a. Monad m => m a -> SerialT m a
$clift :: forall (m :: * -> *) a. Monad m => m a -> SerialT m a
MonadTrans)

-- | A serial IO stream of elements of type @a@. See 'SerialT' documentation
-- for more details.
--
-- /Since: 0.2.0 ("Streamly")/
--
-- @since 0.8.0
type Serial = SerialT IO

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

------------------------------------------------------------------------------
-- Generation
------------------------------------------------------------------------------

{-# INLINE cons #-}
cons :: a -> SerialT m a -> SerialT m a
cons :: forall a (m :: * -> *). a -> SerialT m a -> SerialT m a
cons a
x (SerialT Stream m a
ms) = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall a (m :: * -> *). a -> Stream m a -> Stream m a
K.cons a
x Stream m a
ms

{-# INLINE consM #-}
{-# SPECIALIZE consM :: IO a -> SerialT IO a -> SerialT IO a #-}
consM :: Monad m => m a -> SerialT m a -> SerialT m a
consM :: forall (m :: * -> *) a.
Monad m =>
m a -> SerialT m a -> SerialT m a
consM m a
m (SerialT Stream m a
ms) = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => m a -> Stream m a -> Stream m a
K.consM m a
m Stream m a
ms

-- |
-- Generate an infinite stream by repeating a pure value.
--
{-# INLINE_NORMAL repeat #-}
repeat :: Monad m => a -> SerialT m a
repeat :: forall (m :: * -> *) a. Monad m => a -> SerialT m a
repeat = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. Monad m => Stream m a -> Stream m a
D.toStreamK forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall (m :: * -> *) a. Monad m => a -> Stream m a
D.repeat

------------------------------------------------------------------------------
-- Combining
------------------------------------------------------------------------------

{-# INLINE serial #-}
serial :: SerialT m a -> SerialT m a -> SerialT m a
serial :: forall (m :: * -> *) a. SerialT m a -> SerialT m a -> SerialT m a
serial = forall a. Semigroup a => a -> a -> a
(<>)

------------------------------------------------------------------------------
-- Monad
------------------------------------------------------------------------------

instance Monad m => Monad (SerialT m) where
    return :: forall a. a -> SerialT m a
return = forall (f :: * -> *) a. Applicative f => a -> f a
pure

    -- Benchmarks better with StreamD bind and pure:
    -- toList, filterAllout, *>, *<, >> (~2x)
    --
    -- pure = SerialT . D.fromStreamD . D.fromPure
    -- m >>= f = D.fromStreamD $ D.concatMap (D.toStreamD . f) (D.toStreamD m)

    -- Benchmarks better with CPS bind and pure:
    -- Prime sieve (25x)
    -- n binds, breakAfterSome, filterAllIn, state transformer (~2x)
    --
    {-# INLINE (>>=) #-}
    >>= :: forall a b. SerialT m a -> (a -> SerialT m b) -> SerialT m b
(>>=) (SerialT Stream m a
m) a -> SerialT m b
f = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) b a.
(Stream m b -> Stream m b -> Stream m b)
-> Stream m a -> (a -> Stream m b) -> Stream m b
K.bindWith forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
K.serial Stream m a
m (forall (m :: * -> *) a. SerialT m a -> Stream m a
getSerialT forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> SerialT m b
f)

    {-# INLINE (>>) #-}
    >> :: forall a b. SerialT m a -> SerialT m b -> SerialT m b
(>>)  = forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
(*>)

------------------------------------------------------------------------------
-- Other instances
------------------------------------------------------------------------------

{-# INLINE mapM #-}
mapM :: Monad m => (a -> m b) -> SerialT m a -> SerialT m b
mapM :: forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> SerialT m a -> SerialT m b
mapM a -> m b
f (SerialT Stream m a
m) = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => Stream m a -> Stream m a
D.toStreamK forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> Stream m a -> Stream m b
D.mapM a -> m b
f forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m a
m

-- |
-- @
-- map = fmap
-- @
--
-- Same as 'fmap'.
--
-- @
-- > S.toList $ S.map (+1) $ S.fromList [1,2,3]
-- [2,3,4]
-- @
--
-- @since 0.4.0
{-# INLINE map #-}
map :: Monad m => (a -> b) -> SerialT m a -> SerialT m b
map :: forall (m :: * -> *) a b.
Monad m =>
(a -> b) -> SerialT m a -> SerialT m b
map a -> b
f = forall (m :: * -> *) a b.
Monad m =>
(a -> m b) -> SerialT m a -> SerialT m b
mapM (forall (m :: * -> *) a. Monad m => a -> m a
return forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> b
f)

{-# INLINE apSerial #-}
apSerial :: Monad m => SerialT m (a -> b) -> SerialT m a -> SerialT m b
apSerial :: forall (m :: * -> *) a b.
Monad m =>
SerialT m (a -> b) -> SerialT m a -> SerialT m b
apSerial (SerialT Stream m (a -> b)
m1) (SerialT Stream m a
m2) =
    forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => Stream m a -> Stream m a
D.toStreamK forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m (a -> b)
m1 forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m a
m2

{-# INLINE apSequence #-}
apSequence :: Monad m => SerialT m a -> SerialT m b -> SerialT m b
apSequence :: forall (m :: * -> *) a b.
Monad m =>
SerialT m a -> SerialT m b -> SerialT m b
apSequence (SerialT Stream m a
m1) (SerialT Stream m b
m2) =
    forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => Stream m a -> Stream m a
D.toStreamK forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m a
m1 forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b
*> forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m b
m2

{-# INLINE apDiscardSnd #-}
apDiscardSnd :: Monad m => SerialT m a -> SerialT m b -> SerialT m a
apDiscardSnd :: forall (m :: * -> *) a b.
Monad m =>
SerialT m a -> SerialT m b -> SerialT m a
apDiscardSnd (SerialT Stream m a
m1) (SerialT Stream m b
m2) =
    forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => Stream m a -> Stream m a
D.toStreamK forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m a
m1 forall (f :: * -> *) a b. Applicative f => f a -> f b -> f a
<* forall (m :: * -> *) a. Applicative m => Stream m a -> Stream m a
D.fromStreamK Stream m b
m2

-- Note: we need to define all the typeclass operations because we want to
-- INLINE them.
instance Monad m => Applicative (SerialT m) where
    {-# INLINE pure #-}
    pure :: forall a. a -> SerialT m a
pure = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a (m :: * -> *). a -> Stream m a
K.fromPure

    {-# INLINE (<*>) #-}
    <*> :: forall a b. SerialT m (a -> b) -> SerialT m a -> SerialT m b
(<*>) = forall (m :: * -> *) a b.
Monad m =>
SerialT m (a -> b) -> SerialT m a -> SerialT m b
apSerial
    -- (<*>) = K.apSerial

#if MIN_VERSION_base(4,10,0)
    {-# INLINE liftA2 #-}
    liftA2 :: forall a b c.
(a -> b -> c) -> SerialT m a -> SerialT m b -> SerialT m c
liftA2 a -> b -> c
f SerialT m a
x = forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
(<*>) (forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap a -> b -> c
f SerialT m a
x)
#endif

    {-# INLINE (*>) #-}
    *> :: forall a b. SerialT m a -> SerialT m b -> SerialT m b
(*>)  = forall (m :: * -> *) a b.
Monad m =>
SerialT m a -> SerialT m b -> SerialT m b
apSequence
    -- (*>)  = K.apSerialDiscardFst

    {-# INLINE (<*) #-}
    <* :: forall a b. SerialT m a -> SerialT m b -> SerialT m a
(<*) = forall (m :: * -> *) a b.
Monad m =>
SerialT m a -> SerialT m b -> SerialT m a
apDiscardSnd
    -- (<*)  = K.apSerialDiscardSnd

MONAD_COMMON_INSTANCES(SerialT,)
LIST_INSTANCES(SerialT)
NFDATA1_INSTANCE(SerialT)
FOLDABLE_INSTANCE(SerialT)
TRAVERSABLE_INSTANCE(SerialT)

------------------------------------------------------------------------------
-- WSerialT
------------------------------------------------------------------------------

-- | For 'WSerialT' streams:
--
-- @
-- (<>) = 'Streamly.Prelude.wSerial'                       -- 'Semigroup'
-- (>>=) = flip . 'Streamly.Prelude.concatMapWith' 'Streamly.Prelude.wSerial' -- 'Monad'
-- @
--
-- Note that '<>' is associative only if we disregard the ordering of elements
-- in the resulting stream.
--
-- A single 'Monad' bind behaves like a @for@ loop:
--
-- >>> :{
-- Stream.toList $ Stream.fromWSerial $ do
--      x <- Stream.fromList [1,2] -- foreach x in stream
--      return x
-- :}
-- [1,2]
--
-- Nested monad binds behave like interleaved nested @for@ loops:
--
-- >>> :{
-- Stream.toList $ Stream.fromWSerial $ do
--     x <- Stream.fromList [1,2] -- foreach x in stream
--     y <- Stream.fromList [3,4] -- foreach y in stream
--     return (x, y)
-- :}
-- [(1,3),(2,3),(1,4),(2,4)]
--
-- It is a result of interleaving all the nested iterations corresponding to
-- element @1@ in the first stream with all the nested iterations of element
-- @2@:
--
-- >>> import Streamly.Prelude (wSerial)
-- >>> Stream.toList $ Stream.fromList [(1,3),(1,4)] `Stream.wSerial` Stream.fromList [(2,3),(2,4)]
-- [(1,3),(2,3),(1,4),(2,4)]
--
-- The @W@ in the name stands for @wide@ or breadth wise scheduling in
-- contrast to the depth wise scheduling behavior of 'SerialT'.
--
-- /Since: 0.2.0 ("Streamly")/
--
-- @since 0.8.0
newtype WSerialT m a = WSerialT {forall (m :: * -> *) a. WSerialT m a -> Stream m a
getWSerialT :: Stream m a}
    deriving (forall (m :: * -> *) a. Monad m => m a -> WSerialT m a
forall (t :: (* -> *) -> * -> *).
(forall (m :: * -> *) a. Monad m => m a -> t m a) -> MonadTrans t
lift :: forall (m :: * -> *) a. Monad m => m a -> WSerialT m a
$clift :: forall (m :: * -> *) a. Monad m => m a -> WSerialT m a
MonadTrans)

-- | An interleaving serial IO stream of elements of type @a@. See 'WSerialT'
-- documentation for more details.
--
-- /Since: 0.2.0 ("Streamly")/
--
-- @since 0.8.0
type WSerial = WSerialT IO

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

{-# INLINE consMWSerial #-}
{-# SPECIALIZE consMWSerial :: IO a -> WSerialT IO a -> WSerialT IO a #-}
consMWSerial :: Monad m => m a -> WSerialT m a -> WSerialT m a
consMWSerial :: forall (m :: * -> *) a.
Monad m =>
m a -> WSerialT m a -> WSerialT m a
consMWSerial m a
m (WSerialT Stream m a
ms) = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => m a -> Stream m a -> Stream m a
K.consM m a
m Stream m a
ms

------------------------------------------------------------------------------
-- Semigroup
------------------------------------------------------------------------------

infixr 6 `wSerial`

-- Additionally we can have m elements yield from the first stream and n
-- elements yielding from the second stream. We can also have time slicing
-- variants of positional interleaving, e.g. run first stream for m seconds and
-- run the second stream for n seconds.
--
-- Similar combinators can be implemented using WAhead style.

{-# INLINE wSerialK #-}
wSerialK :: Stream m a -> Stream m a -> Stream m a
wSerialK :: forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK Stream m a
m1 Stream m a
m2 = forall (m :: * -> *) a.
(forall r.
 State Stream m a
 -> (a -> Stream m a -> m r) -> (a -> m r) -> m r -> m r)
-> Stream m a
mkStream forall a b. (a -> b) -> a -> b
$ \State Stream m a
st a -> Stream m a -> m r
yld a -> m r
sng m r
stp -> do
    let stop :: m r
stop       = forall (m :: * -> *) a r.
State Stream m a
-> (a -> Stream m a -> m r)
-> (a -> m r)
-> m r
-> Stream m a
-> m r
foldStream State Stream m a
st a -> Stream m a -> m r
yld a -> m r
sng m r
stp Stream m a
m2
        single :: a -> m r
single a
a   = a -> Stream m a -> m r
yld a
a Stream m a
m2
        yieldk :: a -> Stream m a -> m r
yieldk a
a Stream m a
r = a -> Stream m a -> m r
yld a
a (forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK Stream m a
m2 Stream m a
r)
    forall (m :: * -> *) a r.
State Stream m a
-> (a -> Stream m a -> m r)
-> (a -> m r)
-> m r
-> Stream m a
-> m r
foldStream State Stream m a
st a -> Stream m a -> m r
yieldk a -> m r
single m r
stop Stream m a
m1

-- | Interleaves two streams, yielding one element from each stream
-- alternately.  When one stream stops the rest of the other stream is used in
-- the output stream.

-- Scheduling Notes:
--
-- Note that evaluation of @a \`wSerial` b \`wSerial` c@ does not interleave
-- @a@, @b@ and @c@ with equal priority.  This expression is equivalent to @a
-- \`wSerial` (b \`wSerial` c)@, therefore, it fairly interleaves @a@ with the
-- result of @b \`wSerial` c@.  For example, @Stream.fromList [1,2] \`wSerial`
-- Stream.fromList [3,4] \`wSerial` Stream.fromList [5,6]@ would result in
-- [1,3,2,5,4,6].  In other words, the leftmost stream gets the same scheduling
-- priority as the rest of the streams taken together. The same is true for
-- each subexpression on the right.
--
{-# INLINE wSerial #-}
wSerial :: WSerialT m a -> WSerialT m a -> WSerialT m a
wSerial :: forall (m :: * -> *) a.
WSerialT m a -> WSerialT m a -> WSerialT m a
wSerial (WSerialT Stream m a
m1) (WSerialT Stream m a
m2) = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK Stream m a
m1 Stream m a
m2

-- | Like `wSerial` but stops interleaving as soon as the first stream stops.
--
-- @since 0.7.0
{-# INLINE wSerialFstK #-}
wSerialFstK :: Stream m a -> Stream m a -> Stream m a
wSerialFstK :: forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialFstK Stream m a
m1 Stream m a
m2 = forall (m :: * -> *) a.
(forall r.
 State Stream m a
 -> (a -> Stream m a -> m r) -> (a -> m r) -> m r -> m r)
-> Stream m a
mkStream forall a b. (a -> b) -> a -> b
$ \State Stream m a
st a -> Stream m a -> m r
yld a -> m r
sng m r
stp -> do
    let yieldFirst :: a -> Stream m a -> m r
yieldFirst a
a Stream m a
r = a -> Stream m a -> m r
yld a
a (forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
yieldSecond Stream m a
r Stream m a
m2)
     in forall (m :: * -> *) a r.
State Stream m a
-> (a -> Stream m a -> m r)
-> (a -> m r)
-> m r
-> Stream m a
-> m r
foldStream State Stream m a
st a -> Stream m a -> m r
yieldFirst a -> m r
sng m r
stp Stream m a
m1

    where

    yieldSecond :: Stream m a -> Stream m a -> Stream m a
yieldSecond Stream m a
s1 Stream m a
s2 = forall (m :: * -> *) a.
(forall r.
 State Stream m a
 -> (a -> Stream m a -> m r) -> (a -> m r) -> m r -> m r)
-> Stream m a
mkStream forall a b. (a -> b) -> a -> b
$ \State Stream m a
st a -> Stream m a -> m r
yld a -> m r
sng m r
stp -> do
            let stop :: m r
stop       = forall (m :: * -> *) a r.
State Stream m a
-> (a -> Stream m a -> m r)
-> (a -> m r)
-> m r
-> Stream m a
-> m r
foldStream State Stream m a
st a -> Stream m a -> m r
yld a -> m r
sng m r
stp Stream m a
s1
                single :: a -> m r
single a
a   = a -> Stream m a -> m r
yld a
a Stream m a
s1
                yieldk :: a -> Stream m a -> m r
yieldk a
a Stream m a
r = a -> Stream m a -> m r
yld a
a (forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK Stream m a
s1 Stream m a
r)
             in forall (m :: * -> *) a r.
State Stream m a
-> (a -> Stream m a -> m r)
-> (a -> m r)
-> m r
-> Stream m a
-> m r
foldStream State Stream m a
st a -> Stream m a -> m r
yieldk a -> m r
single m r
stop Stream m a
s2

{-# INLINE wSerialFst #-}
wSerialFst :: WSerialT m a -> WSerialT m a -> WSerialT m a
wSerialFst :: forall (m :: * -> *) a.
WSerialT m a -> WSerialT m a -> WSerialT m a
wSerialFst (WSerialT Stream m a
m1) (WSerialT Stream m a
m2) = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialFstK Stream m a
m1 Stream m a
m2

-- | Like `wSerial` but stops interleaving as soon as any of the two streams
-- stops.
--
-- @since 0.7.0
{-# INLINE wSerialMinK #-}
wSerialMinK :: Stream m a -> Stream m a -> Stream m a
wSerialMinK :: forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialMinK Stream m a
m1 Stream m a
m2 = forall (m :: * -> *) a.
(forall r.
 State Stream m a
 -> (a -> Stream m a -> m r) -> (a -> m r) -> m r -> m r)
-> Stream m a
mkStream forall a b. (a -> b) -> a -> b
$ \State Stream m a
st a -> Stream m a -> m r
yld a -> m r
_ m r
stp -> do
    let stop :: m r
stop       = m r
stp
        -- "single a" is defined as "yld a (wSerialMin m2 K.nil)" instead of
        -- "sng a" to keep the behaviour consistent with the yield continuation.
        single :: a -> m r
single a
a   = a -> Stream m a -> m r
yld a
a (forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialMinK Stream m a
m2 forall (m :: * -> *) a. Stream m a
K.nil)
        yieldk :: a -> Stream m a -> m r
yieldk a
a Stream m a
r = a -> Stream m a -> m r
yld a
a (forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialMinK Stream m a
m2 Stream m a
r)
    forall (m :: * -> *) a r.
State Stream m a
-> (a -> Stream m a -> m r)
-> (a -> m r)
-> m r
-> Stream m a
-> m r
foldStream State Stream m a
st a -> Stream m a -> m r
yieldk a -> m r
single m r
stop Stream m a
m1

{-# INLINE wSerialMin #-}
wSerialMin :: WSerialT m a -> WSerialT m a -> WSerialT m a
wSerialMin :: forall (m :: * -> *) a.
WSerialT m a -> WSerialT m a -> WSerialT m a
wSerialMin (WSerialT Stream m a
m1) (WSerialT Stream m a
m2) = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialMinK Stream m a
m1 Stream m a
m2

instance Semigroup (WSerialT m a) where
    <> :: WSerialT m a -> WSerialT m a -> WSerialT m a
(<>) = forall (m :: * -> *) a.
WSerialT m a -> WSerialT m a -> WSerialT m a
wSerial

------------------------------------------------------------------------------
-- Monoid
------------------------------------------------------------------------------

instance Monoid (WSerialT m a) where
    mempty :: WSerialT m a
mempty = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall (m :: * -> *) a. Stream m a
K.nil
    mappend :: WSerialT m a -> WSerialT m a -> WSerialT m a
mappend = forall a. Semigroup a => a -> a -> a
(<>)

{-# INLINE apWSerial #-}
apWSerial :: Monad m => WSerialT m (a -> b) -> WSerialT m a -> WSerialT m b
apWSerial :: forall (m :: * -> *) a b.
Monad m =>
WSerialT m (a -> b) -> WSerialT m a -> WSerialT m b
apWSerial (WSerialT Stream m (a -> b)
m1) (WSerialT Stream m a
m2) =
    let f :: (a -> b) -> Stream m b
f a -> b
x1 = forall (m :: * -> *) b a.
(Stream m b -> Stream m b -> Stream m b)
-> (a -> Stream m b) -> Stream m a -> Stream m b
K.concatMapWith forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK (forall (f :: * -> *) a. Applicative f => a -> f a
pure forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> b
x1) Stream m a
m2
    in forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) b a.
(Stream m b -> Stream m b -> Stream m b)
-> (a -> Stream m b) -> Stream m a -> Stream m b
K.concatMapWith forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK forall {b}. (a -> b) -> Stream m b
f Stream m (a -> b)
m1

instance Monad m => Applicative (WSerialT m) where
    {-# INLINE pure #-}
    pure :: forall a. a -> WSerialT m a
pure = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall b c a. (b -> c) -> (a -> b) -> a -> c
. forall a (m :: * -> *). a -> Stream m a
K.fromPure
    {-# INLINE (<*>) #-}
    <*> :: forall a b. WSerialT m (a -> b) -> WSerialT m a -> WSerialT m b
(<*>) = forall (m :: * -> *) a b.
Monad m =>
WSerialT m (a -> b) -> WSerialT m a -> WSerialT m b
apWSerial

------------------------------------------------------------------------------
-- Monad
------------------------------------------------------------------------------

instance Monad m => Monad (WSerialT m) where
    return :: forall a. a -> WSerialT m a
return = forall (f :: * -> *) a. Applicative f => a -> f a
pure
    {-# INLINE (>>=) #-}
    >>= :: forall a b. WSerialT m a -> (a -> WSerialT m b) -> WSerialT m b
(>>=) (WSerialT Stream m a
m) a -> WSerialT m b
f = forall (m :: * -> *) a. Stream m a -> WSerialT m a
WSerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) b a.
(Stream m b -> Stream m b -> Stream m b)
-> Stream m a -> (a -> Stream m b) -> Stream m b
K.bindWith forall (m :: * -> *) a. Stream m a -> Stream m a -> Stream m a
wSerialK Stream m a
m (forall (m :: * -> *) a. WSerialT m a -> Stream m a
getWSerialT forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> WSerialT m b
f)

------------------------------------------------------------------------------
-- Other instances
------------------------------------------------------------------------------

MONAD_COMMON_INSTANCES(WSerialT,)
LIST_INSTANCES(WSerialT)
NFDATA1_INSTANCE(WSerialT)
FOLDABLE_INSTANCE(WSerialT)
TRAVERSABLE_INSTANCE(WSerialT)

------------------------------------------------------------------------------
-- Construction
------------------------------------------------------------------------------

-- | Build a stream by unfolding a /monadic/ step function starting from a
-- seed.  The step function returns the next element in the stream and the next
-- seed value. When it is done it returns 'Nothing' and the stream ends. For
-- example,
--
-- @
-- let f b =
--         if b > 3
--         then return Nothing
--         else print b >> return (Just (b, b + 1))
-- in drain $ unfoldrM f 0
-- @
-- @
--  0
--  1
--  2
--  3
-- @
--
-- /Pre-release/
--
{-# INLINE unfoldrM #-}
unfoldrM :: Monad m => (b -> m (Maybe (a, b))) -> b -> SerialT m a
unfoldrM :: forall (m :: * -> *) b a.
Monad m =>
(b -> m (Maybe (a, b))) -> b -> SerialT m a
unfoldrM b -> m (Maybe (a, b))
step b
seed = forall (m :: * -> *) a. Stream m a -> SerialT m a
SerialT forall a b. (a -> b) -> a -> b
$ forall (m :: * -> *) a. Monad m => Stream m a -> Stream m a
D.toStreamK (forall (m :: * -> *) s a.
Monad m =>
(s -> m (Maybe (a, s))) -> s -> Stream m a
D.unfoldrM b -> m (Maybe (a, b))
step b
seed)