Streamly.Internal.Data.List

Lists are just a special case of monadic streams. The stream type SerialT Identity a can be used as a replacement for [a]. The List type in this module is just a newtype wrapper around SerialT Identity for better type inference when using the OverloadedLists GHC extension. List a provides better performance compared to [a]. Standard list, string and list comprehension syntax can be used with the List type by enabling OverloadedLists, OverloadedStrings and MonadComprehensions GHC extensions. There would be a slight difference in the Show and Read strings of streamly list as compared to regular lists.

Conversion to stream types is free, any stream combinator can be used on lists by converting them to streams. However, for convenience, this module provides combinators that work directly on the List type.

List $ S.map (+ 1) $ toSerial (1 `Cons` Nil)

To convert a List to regular lists, you can use any of the following:

• toList . toSerial and toSerial . fromList
• toList from Data.Foldable
• toList and fromList from IsList in GHC.Exts

If you have made use of Nil and Cons constructors in the code and you want to replace streamly lists with standard lists, all you need to do is import these definitions:

type List = []
pattern Nil <- [] where Nil = []
pattern Cons x xs = x : xs
infixr 5 Cons
{-# COMPLETE Cons, Nil #-}

See src/docs/streamly-vs-lists.md for more details and src/test/PureStreams.hs for comprehensive usage examples.

Documentation

newtype List a

List a is a replacement for [a].

Since: 0.6.0

Constructors

List

Fields

• toSerial :: SerialT Identity a

Bundled Patterns

pattern Nil :: List a

An empty list constructor and pattern that matches an empty List. Corresponds to '[]' for Haskell lists.

Since: 0.6.0

pattern Cons :: a -> List a -> List a infixr 5

A list constructor and pattern that deconstructs a List into its head and tail. Corresponds to : for Haskell lists.

Since: 0.6.0

Instances

Monad List

Defined in Streamly.Internal.Data.List

Methods

(>>=) :: List a -> (a -> List b) -> List b

(>>) :: List a -> List b -> List b

return :: a -> List a

fail :: String -> List a

Functor List

Defined in Streamly.Internal.Data.List

Methods

fmap :: (a -> b) -> List a -> List b

(<$) :: a -> List b -> List a

Applicative List

Defined in Streamly.Internal.Data.List

Methods

pure :: a -> List a

(<*>) :: List (a -> b) -> List a -> List b

liftA2 :: (a -> b -> c) -> List a -> List b -> List c

(*>) :: List a -> List b -> List b

(<*) :: List a -> List b -> List a

Foldable List

Defined in Streamly.Internal.Data.List

Methods

fold :: Monoid m => List m -> m

foldMap :: Monoid m => (a -> m) -> List a -> m

foldr :: (a -> b -> b) -> b -> List a -> b

foldr' :: (a -> b -> b) -> b -> List a -> b

foldl :: (b -> a -> b) -> b -> List a -> b

foldl' :: (b -> a -> b) -> b -> List a -> b

foldr1 :: (a -> a -> a) -> List a -> a

foldl1 :: (a -> a -> a) -> List a -> a

toList :: List a -> [a]

null :: List a -> Bool

length :: List a -> Int

elem :: Eq a => a -> List a -> Bool

maximum :: Ord a => List a -> a

minimum :: Ord a => List a -> a

sum :: Num a => List a -> a

product :: Num a => List a -> a

Traversable List

Defined in Streamly.Internal.Data.List

Methods

traverse :: Applicative f => (a -> f b) -> List a -> f (List b)

sequenceA :: Applicative f => List (f a) -> f (List a)

mapM :: Monad m => (a -> m b) -> List a -> m (List b)

sequence :: Monad m => List (m a) -> m (List a)

NFData1 List

Defined in Streamly.Internal.Data.List

Methods

liftRnf :: (a -> ()) -> List a -> ()

IsList (List a)

Defined in Streamly.Internal.Data.List

Associated Types

type Item (List a) :: Type

Methods

fromList :: [Item (List a)] -> List a

fromListN :: Int -> [Item (List a)] -> List a

toList :: List a -> [Item (List a)]

Eq a => Eq (List a)

Defined in Streamly.Internal.Data.List

Methods

(==) :: List a -> List a -> Bool

(/=) :: List a -> List a -> Bool

Ord a => Ord (List a)

Defined in Streamly.Internal.Data.List

Methods

compare :: List a -> List a -> Ordering

(<) :: List a -> List a -> Bool

(<=) :: List a -> List a -> Bool

(>) :: List a -> List a -> Bool

(>=) :: List a -> List a -> Bool

max :: List a -> List a -> List a

min :: List a -> List a -> List a

Read a => Read (List a)

Defined in Streamly.Internal.Data.List

Methods

readsPrec :: Int -> ReadS (List a)

readList :: ReadS [List a]

readPrec :: ReadPrec (List a)

readListPrec :: ReadPrec [List a]

Show a => Show (List a)

Defined in Streamly.Internal.Data.List

Methods

showsPrec :: Int -> List a -> ShowS

show :: List a -> String

showList :: [List a] -> ShowS

a ~ Char => IsString (List a)

Defined in Streamly.Internal.Data.List

Methods

fromString :: String -> List a

Semigroup (List a)

Defined in Streamly.Internal.Data.List

Methods

(<>) :: List a -> List a -> List a

sconcat :: NonEmpty (List a) -> List a

stimes :: Integral b => b -> List a -> List a

Monoid (List a)

Defined in Streamly.Internal.Data.List

Methods

mempty :: List a

mappend :: List a -> List a -> List a

mconcat :: [List a] -> List a

NFData a => NFData (List a)

Defined in Streamly.Internal.Data.List

Methods

rnf :: List a -> ()

type Item (List a)

Defined in Streamly.Internal.Data.List

type Item (List a) = a

newtype ZipList a

Just like List except that it has a zipping Applicative instance and no Monad instance.

Since: 0.6.0

Constructors

ZipList

Fields

• toZipSerial :: ZipSerialM Identity a

Instances

Functor ZipList

Defined in Streamly.Internal.Data.List

Methods

fmap :: (a -> b) -> ZipList a -> ZipList b

(<$) :: a -> ZipList b -> ZipList a

Applicative ZipList

Defined in Streamly.Internal.Data.List

Methods

pure :: a -> ZipList a

(<*>) :: ZipList (a -> b) -> ZipList a -> ZipList b

liftA2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c

(*>) :: ZipList a -> ZipList b -> ZipList b

(<*) :: ZipList a -> ZipList b -> ZipList a

Foldable ZipList

Defined in Streamly.Internal.Data.List

Methods

fold :: Monoid m => ZipList m -> m

foldMap :: Monoid m => (a -> m) -> ZipList a -> m

foldr :: (a -> b -> b) -> b -> ZipList a -> b

foldr' :: (a -> b -> b) -> b -> ZipList a -> b

foldl :: (b -> a -> b) -> b -> ZipList a -> b

foldl' :: (b -> a -> b) -> b -> ZipList a -> b

foldr1 :: (a -> a -> a) -> ZipList a -> a

foldl1 :: (a -> a -> a) -> ZipList a -> a

toList :: ZipList a -> [a]

null :: ZipList a -> Bool

length :: ZipList a -> Int

elem :: Eq a => a -> ZipList a -> Bool

maximum :: Ord a => ZipList a -> a

minimum :: Ord a => ZipList a -> a

sum :: Num a => ZipList a -> a

product :: Num a => ZipList a -> a

Traversable ZipList

Defined in Streamly.Internal.Data.List

Methods

traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b)

sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a)

mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b)

sequence :: Monad m => ZipList (m a) -> m (ZipList a)

NFData1 ZipList

Defined in Streamly.Internal.Data.List

Methods

liftRnf :: (a -> ()) -> ZipList a -> ()

IsList (ZipList a)

Defined in Streamly.Internal.Data.List

Associated Types

type Item (ZipList a) :: Type

Methods

fromList :: [Item (ZipList a)] -> ZipList a

fromListN :: Int -> [Item (ZipList a)] -> ZipList a

toList :: ZipList a -> [Item (ZipList a)]

Eq a => Eq (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

(==) :: ZipList a -> ZipList a -> Bool

(/=) :: ZipList a -> ZipList a -> Bool

Ord a => Ord (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

compare :: ZipList a -> ZipList a -> Ordering

(<) :: ZipList a -> ZipList a -> Bool

(<=) :: ZipList a -> ZipList a -> Bool

(>) :: ZipList a -> ZipList a -> Bool

(>=) :: ZipList a -> ZipList a -> Bool

max :: ZipList a -> ZipList a -> ZipList a

min :: ZipList a -> ZipList a -> ZipList a

Read a => Read (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

readsPrec :: Int -> ReadS (ZipList a)

readList :: ReadS [ZipList a]

readPrec :: ReadPrec (ZipList a)

readListPrec :: ReadPrec [ZipList a]

Show a => Show (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

showsPrec :: Int -> ZipList a -> ShowS

show :: ZipList a -> String

showList :: [ZipList a] -> ShowS

a ~ Char => IsString (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

fromString :: String -> ZipList a

Semigroup (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

(<>) :: ZipList a -> ZipList a -> ZipList a

sconcat :: NonEmpty (ZipList a) -> ZipList a

stimes :: Integral b => b -> ZipList a -> ZipList a

Monoid (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

mempty :: ZipList a

mappend :: ZipList a -> ZipList a -> ZipList a

mconcat :: [ZipList a] -> ZipList a

NFData a => NFData (ZipList a)

Defined in Streamly.Internal.Data.List

Methods

rnf :: ZipList a -> ()

type Item (ZipList a)

Defined in Streamly.Internal.Data.List

type Item (ZipList a) = a

fromZipList :: ZipList a -> List a

Convert a ZipList to a regular List

Since: 0.6.0

toZipList :: List a -> ZipList a

Convert a regular List to a ZipList

Since: 0.6.0