{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE CPP #-}
#if __GLASGOW_HASKELL__ >= 702
{-# LANGUAGE Trustworthy #-}
#endif
-----------------------------------------------------------------------------
-- |
-- Module      :  Data.Stream.Future
-- Copyright   :  (C) 2011-2015 Edward Kmett
-- License     :  BSD-style (see the file LICENSE)
--
-- Maintainer  :  Edward Kmett <ekmett@gmail.com>
-- Stability   :  provisional
-- Portability :  portable
--
----------------------------------------------------------------------------

module Data.Stream.Future
  ( Future(..)
  , tail
  , length
  , index
  ) where

#if MIN_VERSION_base(4,8,0)
import Prelude hiding (tail)
#else
import Control.Applicative
import Prelude hiding (tail, length)
import Data.Foldable
#endif

import Control.Comonad
import Data.Functor.Alt
import Data.Functor.Extend
import Data.Traversable
#if !(MIN_VERSION_base(4,11,0))
import Data.Semigroup hiding (Last)
#endif
import Data.Semigroup.Foldable
import Data.Semigroup.Traversable

#ifdef LANGUAGE_DeriveDataTypeable
import Data.Data
#endif

#if MIN_VERSION_base(4,7,0)
import GHC.Exts as Exts
#endif

infixr 5 :<

data Future a = Last a | a :< Future a deriving
  ( Future a -> Future a -> Bool
forall a. Eq a => Future a -> Future a -> Bool
forall a. (a -> a -> Bool) -> (a -> a -> Bool) -> Eq a
/= :: Future a -> Future a -> Bool
$c/= :: forall a. Eq a => Future a -> Future a -> Bool
== :: Future a -> Future a -> Bool
$c== :: forall a. Eq a => Future a -> Future a -> Bool
Eq, Future a -> Future a -> Bool
Future a -> Future a -> Ordering
forall a.
Eq a
-> (a -> a -> Ordering)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> Bool)
-> (a -> a -> a)
-> (a -> a -> a)
-> Ord a
forall {a}. Ord a => Eq (Future a)
forall a. Ord a => Future a -> Future a -> Bool
forall a. Ord a => Future a -> Future a -> Ordering
forall a. Ord a => Future a -> Future a -> Future a
min :: Future a -> Future a -> Future a
$cmin :: forall a. Ord a => Future a -> Future a -> Future a
max :: Future a -> Future a -> Future a
$cmax :: forall a. Ord a => Future a -> Future a -> Future a
>= :: Future a -> Future a -> Bool
$c>= :: forall a. Ord a => Future a -> Future a -> Bool
> :: Future a -> Future a -> Bool
$c> :: forall a. Ord a => Future a -> Future a -> Bool
<= :: Future a -> Future a -> Bool
$c<= :: forall a. Ord a => Future a -> Future a -> Bool
< :: Future a -> Future a -> Bool
$c< :: forall a. Ord a => Future a -> Future a -> Bool
compare :: Future a -> Future a -> Ordering
$ccompare :: forall a. Ord a => Future a -> Future a -> Ordering
Ord, Int -> Future a -> ShowS
forall a. Show a => Int -> Future a -> ShowS
forall a. Show a => [Future a] -> ShowS
forall a. Show a => Future a -> String
forall a.
(Int -> a -> ShowS) -> (a -> String) -> ([a] -> ShowS) -> Show a
showList :: [Future a] -> ShowS
$cshowList :: forall a. Show a => [Future a] -> ShowS
show :: Future a -> String
$cshow :: forall a. Show a => Future a -> String
showsPrec :: Int -> Future a -> ShowS
$cshowsPrec :: forall a. Show a => Int -> Future a -> ShowS
Show, ReadPrec [Future a]
ReadPrec (Future a)
ReadS [Future a]
forall a. Read a => ReadPrec [Future a]
forall a. Read a => ReadPrec (Future a)
forall a. Read a => Int -> ReadS (Future a)
forall a. Read a => ReadS [Future a]
forall a.
(Int -> ReadS a)
-> ReadS [a] -> ReadPrec a -> ReadPrec [a] -> Read a
readListPrec :: ReadPrec [Future a]
$creadListPrec :: forall a. Read a => ReadPrec [Future a]
readPrec :: ReadPrec (Future a)
$creadPrec :: forall a. Read a => ReadPrec (Future a)
readList :: ReadS [Future a]
$creadList :: forall a. Read a => ReadS [Future a]
readsPrec :: Int -> ReadS (Future a)
$creadsPrec :: forall a. Read a => Int -> ReadS (Future a)
Read
#ifdef LANGUAGE_DeriveDataTypeable
  , Future a -> DataType
Future a -> Constr
forall {a}. Data a => Typeable (Future a)
forall a. Data a => Future a -> DataType
forall a. Data a => Future a -> Constr
forall a.
Data a =>
(forall b. Data b => b -> b) -> Future a -> Future a
forall a u.
Data a =>
Int -> (forall d. Data d => d -> u) -> Future a -> u
forall a u.
Data a =>
(forall d. Data d => d -> u) -> Future a -> [u]
forall a r r'.
Data a =>
(r -> r' -> r)
-> r -> (forall d. Data d => d -> r') -> Future a -> r
forall a r r'.
Data a =>
(r' -> r -> r)
-> r -> (forall d. Data d => d -> r') -> Future a -> r
forall a (m :: * -> *).
(Data a, Monad m) =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
forall a (m :: * -> *).
(Data a, MonadPlus m) =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
forall a (c :: * -> *).
Data a =>
(forall b r. Data b => c (b -> r) -> c r)
-> (forall r. r -> c r) -> Constr -> c (Future a)
forall a (c :: * -> *).
Data a =>
(forall d b. Data d => c (d -> b) -> d -> c b)
-> (forall g. g -> c g) -> Future a -> c (Future a)
forall a (t :: * -> *) (c :: * -> *).
(Data a, Typeable t) =>
(forall d. Data d => c (t d)) -> Maybe (c (Future a))
forall a (t :: * -> * -> *) (c :: * -> *).
(Data a, Typeable t) =>
(forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Future a))
forall a.
Typeable a
-> (forall (c :: * -> *).
    (forall d b. Data d => c (d -> b) -> d -> c b)
    -> (forall g. g -> c g) -> a -> c a)
-> (forall (c :: * -> *).
    (forall b r. Data b => c (b -> r) -> c r)
    -> (forall r. r -> c r) -> Constr -> c a)
-> (a -> Constr)
-> (a -> DataType)
-> (forall (t :: * -> *) (c :: * -> *).
    Typeable t =>
    (forall d. Data d => c (t d)) -> Maybe (c a))
-> (forall (t :: * -> * -> *) (c :: * -> *).
    Typeable t =>
    (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c a))
-> ((forall b. Data b => b -> b) -> a -> a)
-> (forall r r'.
    (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> a -> r)
-> (forall r r'.
    (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> a -> r)
-> (forall u. (forall d. Data d => d -> u) -> a -> [u])
-> (forall u. Int -> (forall d. Data d => d -> u) -> a -> u)
-> (forall (m :: * -> *).
    Monad m =>
    (forall d. Data d => d -> m d) -> a -> m a)
-> (forall (m :: * -> *).
    MonadPlus m =>
    (forall d. Data d => d -> m d) -> a -> m a)
-> (forall (m :: * -> *).
    MonadPlus m =>
    (forall d. Data d => d -> m d) -> a -> m a)
-> Data a
forall (c :: * -> *).
(forall b r. Data b => c (b -> r) -> c r)
-> (forall r. r -> c r) -> Constr -> c (Future a)
forall (c :: * -> *).
(forall d b. Data d => c (d -> b) -> d -> c b)
-> (forall g. g -> c g) -> Future a -> c (Future a)
forall (t :: * -> *) (c :: * -> *).
Typeable t =>
(forall d. Data d => c (t d)) -> Maybe (c (Future a))
gmapMo :: forall (m :: * -> *).
MonadPlus m =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
$cgmapMo :: forall a (m :: * -> *).
(Data a, MonadPlus m) =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
gmapMp :: forall (m :: * -> *).
MonadPlus m =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
$cgmapMp :: forall a (m :: * -> *).
(Data a, MonadPlus m) =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
gmapM :: forall (m :: * -> *).
Monad m =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
$cgmapM :: forall a (m :: * -> *).
(Data a, Monad m) =>
(forall d. Data d => d -> m d) -> Future a -> m (Future a)
gmapQi :: forall u. Int -> (forall d. Data d => d -> u) -> Future a -> u
$cgmapQi :: forall a u.
Data a =>
Int -> (forall d. Data d => d -> u) -> Future a -> u
gmapQ :: forall u. (forall d. Data d => d -> u) -> Future a -> [u]
$cgmapQ :: forall a u.
Data a =>
(forall d. Data d => d -> u) -> Future a -> [u]
gmapQr :: forall r r'.
(r' -> r -> r)
-> r -> (forall d. Data d => d -> r') -> Future a -> r
$cgmapQr :: forall a r r'.
Data a =>
(r' -> r -> r)
-> r -> (forall d. Data d => d -> r') -> Future a -> r
gmapQl :: forall r r'.
(r -> r' -> r)
-> r -> (forall d. Data d => d -> r') -> Future a -> r
$cgmapQl :: forall a r r'.
Data a =>
(r -> r' -> r)
-> r -> (forall d. Data d => d -> r') -> Future a -> r
gmapT :: (forall b. Data b => b -> b) -> Future a -> Future a
$cgmapT :: forall a.
Data a =>
(forall b. Data b => b -> b) -> Future a -> Future a
dataCast2 :: forall (t :: * -> * -> *) (c :: * -> *).
Typeable t =>
(forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Future a))
$cdataCast2 :: forall a (t :: * -> * -> *) (c :: * -> *).
(Data a, Typeable t) =>
(forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Future a))
dataCast1 :: forall (t :: * -> *) (c :: * -> *).
Typeable t =>
(forall d. Data d => c (t d)) -> Maybe (c (Future a))
$cdataCast1 :: forall a (t :: * -> *) (c :: * -> *).
(Data a, Typeable t) =>
(forall d. Data d => c (t d)) -> Maybe (c (Future a))
dataTypeOf :: Future a -> DataType
$cdataTypeOf :: forall a. Data a => Future a -> DataType
toConstr :: Future a -> Constr
$ctoConstr :: forall a. Data a => Future a -> Constr
gunfold :: forall (c :: * -> *).
(forall b r. Data b => c (b -> r) -> c r)
-> (forall r. r -> c r) -> Constr -> c (Future a)
$cgunfold :: forall a (c :: * -> *).
Data a =>
(forall b r. Data b => c (b -> r) -> c r)
-> (forall r. r -> c r) -> Constr -> c (Future a)
gfoldl :: forall (c :: * -> *).
(forall d b. Data d => c (d -> b) -> d -> c b)
-> (forall g. g -> c g) -> Future a -> c (Future a)
$cgfoldl :: forall a (c :: * -> *).
Data a =>
(forall d b. Data d => c (d -> b) -> d -> c b)
-> (forall g. g -> c g) -> Future a -> c (Future a)
Data, Typeable
#endif
  )

#if __GLASGOW_HASKELL__ < 710
length :: Future a -> Int
length = go 1
  where
    go !n (Last _)  = n
    go !n (_ :< as) = go (n + 1) as
{-# INLINE length #-}
#endif

tail :: Future a -> Maybe (Future a)
tail :: forall a. Future a -> Maybe (Future a)
tail (Last a
_) = forall a. Maybe a
Nothing
tail (a
_ :< Future a
as) = forall a. a -> Maybe a
Just Future a
as
{-# INLINE tail #-}

index :: Int -> Future a -> a
index :: forall a. Int -> Future a -> a
index Int
n Future a
aas
  | Int
n forall a. Ord a => a -> a -> Bool
< Int
0 = forall a. HasCallStack => String -> a
error String
"index: negative index"
  | Int
n forall a. Eq a => a -> a -> Bool
== Int
0 = forall (w :: * -> *) a. Comonad w => w a -> a
extract Future a
aas
  | Bool
otherwise = case Future a
aas of
    Last a
_ -> forall a. HasCallStack => String -> a
error String
"index: out of range"
    a
_ :< Future a
as -> forall a. Int -> Future a -> a
index (Int
n forall a. Num a => a -> a -> a
- Int
1) Future a
as

instance Functor Future where
  fmap :: forall a b. (a -> b) -> Future a -> Future b
fmap a -> b
f (a
a :< Future a
as) = a -> b
f a
a forall a. a -> Future a -> Future a
:< forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
fmap a -> b
f Future a
as
  fmap a -> b
f (Last a
a)  = forall a. a -> Future a
Last (a -> b
f a
a)
  a
b <$ :: forall a b. a -> Future b -> Future a
<$ (b
_ :< Future b
as) = a
b forall a. a -> Future a -> Future a
:< (a
b forall (f :: * -> *) a b. Functor f => a -> f b -> f a
<$ Future b
as)
  a
b <$ Future b
_         = forall a. a -> Future a
Last a
b

instance Foldable Future where
  foldMap :: forall m a. Monoid m => (a -> m) -> Future a -> m
foldMap = forall (t :: * -> *) m a.
(Traversable t, Monoid m) =>
(a -> m) -> t a -> m
foldMapDefault
#if __GLASGOW_HASKELL__ >= 710
  length :: forall a. Future a -> Int
length = forall {t} {a}. Num t => t -> Future a -> t
go Int
1
    where
      go :: t -> Future a -> t
go !t
n (Last a
_)  = t
n
      go !t
n (a
_ :< Future a
as) = t -> Future a -> t
go (t
n forall a. Num a => a -> a -> a
+ t
1) Future a
as
  {-# INLINE length #-}
  null :: forall a. Future a -> Bool
null Future a
_ = Bool
False
#endif

instance Traversable Future where
  traverse :: forall (f :: * -> *) a b.
Applicative f =>
(a -> f b) -> Future a -> f (Future b)
traverse a -> f b
f (Last a
a)  = forall a. a -> Future a
Last forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> a -> f b
f a
a
  traverse a -> f b
f (a
a :< Future a
as) = forall a. a -> Future a -> Future a
(:<) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> a -> f b
f a
a forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
traverse a -> f b
f Future a
as

instance Foldable1 Future where
  foldMap1 :: forall m a. Semigroup m => (a -> m) -> Future a -> m
foldMap1 = forall (f :: * -> *) m a.
(Traversable1 f, Semigroup m) =>
(a -> m) -> f a -> m
foldMap1Default

instance Traversable1 Future where
  traverse1 :: forall (f :: * -> *) a b.
Apply f =>
(a -> f b) -> Future a -> f (Future b)
traverse1 a -> f b
f (Last a
a)  = forall a. a -> Future a
Last forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> a -> f b
f a
a
  traverse1 a -> f b
f (a
a :< Future a
as) = forall a. a -> Future a -> Future a
(:<) forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> a -> f b
f a
a forall (f :: * -> *) a b. Apply f => f (a -> b) -> f a -> f b
<.> forall (t :: * -> *) (f :: * -> *) a b.
(Traversable1 t, Apply f) =>
(a -> f b) -> t a -> f (t b)
traverse1 a -> f b
f Future a
as

instance Extend Future where
  extended :: forall a b. (Future a -> b) -> Future a -> Future b
extended = forall (w :: * -> *) a b. Comonad w => (w a -> b) -> w a -> w b
extend

instance Comonad Future where
  extract :: forall a. Future a -> a
extract (Last a
a) = a
a
  extract (a
a :< Future a
_) = a
a

  duplicate :: forall a. Future a -> Future (Future a)
duplicate w :: Future a
w@(a
_ :< Future a
as) = Future a
w forall a. a -> Future a -> Future a
:< forall (w :: * -> *) a. Comonad w => w a -> w (w a)
duplicate Future a
as
  duplicate w :: Future a
w@(Last a
_)  = forall a. a -> Future a
Last Future a
w

  extend :: forall a b. (Future a -> b) -> Future a -> Future b
extend Future a -> b
f w :: Future a
w@(a
_ :< Future a
as) = Future a -> b
f Future a
w forall a. a -> Future a -> Future a
:< forall (w :: * -> *) a b. Comonad w => (w a -> b) -> w a -> w b
extend Future a -> b
f Future a
as
  extend Future a -> b
f w :: Future a
w@(Last a
_)  = forall a. a -> Future a
Last (Future a -> b
f Future a
w)

instance Apply Future where
  Last a -> b
f    <.> :: forall a b. Future (a -> b) -> Future a -> Future b
<.> Last a
a    = forall a. a -> Future a
Last (a -> b
f a
a)
  (a -> b
f :< Future (a -> b)
_)  <.> Last a
a    = forall a. a -> Future a
Last (a -> b
f a
a)
  Last a -> b
f    <.> (a
a :< Future a
_ ) = forall a. a -> Future a
Last (a -> b
f a
a)
  (a -> b
f :< Future (a -> b)
fs) <.> (a
a :< Future a
as) = a -> b
f a
a forall a. a -> Future a -> Future a
:< (Future (a -> b)
fs forall (f :: * -> *) a b. Apply f => f (a -> b) -> f a -> f b
<.> Future a
as)

  Last a
a    <. :: forall a b. Future a -> Future b -> Future a
<. Future b
_         = forall a. a -> Future a
Last a
a
  (a
a :< Future a
_ ) <. Last b
_    = forall a. a -> Future a
Last a
a
  (a
a :< Future a
as) <. (b
_ :< Future b
bs) = a
a forall a. a -> Future a -> Future a
:< (Future a
as forall (f :: * -> *) a b. Apply f => f a -> f b -> f a
<. Future b
bs)

  Future a
_          .> :: forall a b. Future a -> Future b -> Future b
.> Last b
b   = forall a. a -> Future a
Last b
b
  Last a
_     .> (b
b :< Future b
_) = forall a. a -> Future a
Last b
b
  (a
_ :< Future a
as)  .> (b
b :< Future b
bs) = b
b forall a. a -> Future a -> Future a
:< (Future a
as forall (f :: * -> *) a b. Apply f => f a -> f b -> f b
.> Future b
bs)

instance ComonadApply Future where
  <@> :: forall a b. Future (a -> b) -> Future a -> Future b
(<@>) = forall (f :: * -> *) a b. Apply f => f (a -> b) -> f a -> f b
(<.>)

instance Alt Future where
  Last a
a    <!> :: forall a. Future a -> Future a -> Future a
<!> Future a
bs = a
a forall a. a -> Future a -> Future a
:< Future a
bs
  (a
a :< Future a
as) <!> Future a
bs = a
a forall a. a -> Future a -> Future a
:< (Future a
as forall (f :: * -> *) a. Alt f => f a -> f a -> f a
<!> Future a
bs)

instance Semigroup (Future a) where
  <> :: Future a -> Future a -> Future a
(<>) = forall (f :: * -> *) a. Alt f => f a -> f a -> f a
(<!>)

instance Applicative Future where
  pure :: forall a. a -> Future a
pure = forall a. a -> Future a
Last
  <*> :: forall a b. Future (a -> b) -> Future a -> Future b
(<*>) = forall (f :: * -> *) a b. Apply f => f (a -> b) -> f a -> f b
(<.>)
  (<* ) = (<. )
  ( *>) = ( .>)

#if MIN_VERSION_base(4,7,0)
instance Exts.IsList (Future a) where
  type Item (Future a) = a

  toList :: Future a -> [Item (Future a)]
toList (Last a
a) = [a
a]
  toList (a
a :< Future a
as) = a
a forall a. a -> [a] -> [a]
: forall l. IsList l => l -> [Item l]
Exts.toList Future a
as

  fromList :: [Item (Future a)] -> Future a
fromList [] = forall a. HasCallStack => String -> a
error String
"Future.fromList: empty list"
  fromList (Item (Future a)
x:[Item (Future a)]
xs) = forall {t}. t -> [t] -> Future t
go Item (Future a)
x [Item (Future a)]
xs where
    go :: t -> [t] -> Future t
go t
y [] = forall a. a -> Future a
Last t
y
    go t
y (t
z:[t]
zs) = t
y forall a. a -> Future a -> Future a
:< t -> [t] -> Future t
go t
z [t]
zs

  fromListN :: Int -> [Item (Future a)] -> Future a
fromListN Int
_ = forall l. IsList l => [Item l] -> l
Exts.fromList
#endif