Portability | non-portable |
---|---|

Stability | experimental |

Maintainer | Roman Leshchinskiy <rl@cse.unsw.edu.au> |

Monadic stream combinators.

- data Stream m a = forall s . Stream (s -> m (Step s a)) s Size
- data Step s a
- size :: Stream m a -> Size
- sized :: Stream m a -> Size -> Stream m a
- length :: Monad m => Stream m a -> m Int
- null :: Monad m => Stream m a -> m Bool
- empty :: Monad m => Stream m a
- singleton :: Monad m => a -> Stream m a
- cons :: Monad m => a -> Stream m a -> Stream m a
- snoc :: Monad m => Stream m a -> a -> Stream m a
- replicate :: Monad m => Int -> a -> Stream m a
- replicateM :: Monad m => Int -> m a -> Stream m a
- generate :: Monad m => Int -> (Int -> a) -> Stream m a
- generateM :: Monad m => Int -> (Int -> m a) -> Stream m a
- (++) :: Monad m => Stream m a -> Stream m a -> Stream m a
- head :: Monad m => Stream m a -> m a
- last :: Monad m => Stream m a -> m a
- (!!) :: Monad m => Stream m a -> Int -> m a
- (!?) :: Monad m => Stream m a -> Int -> m (Maybe a)
- slice :: Monad m => Int -> Int -> Stream m a -> Stream m a
- init :: Monad m => Stream m a -> Stream m a
- tail :: Monad m => Stream m a -> Stream m a
- take :: Monad m => Int -> Stream m a -> Stream m a
- drop :: Monad m => Int -> Stream m a -> Stream m a
- map :: Monad m => (a -> b) -> Stream m a -> Stream m b
- mapM :: Monad m => (a -> m b) -> Stream m a -> Stream m b
- mapM_ :: Monad m => (a -> m b) -> Stream m a -> m ()
- trans :: (Monad m, Monad m') => (forall a. m a -> m' a) -> Stream m a -> Stream m' a
- unbox :: Monad m => Stream m (Box a) -> Stream m a
- concatMap :: Monad m => (a -> Stream m b) -> Stream m a -> Stream m b
- flatten :: Monad m => (a -> m s) -> (s -> m (Step s b)) -> Size -> Stream m a -> Stream m b
- indexed :: Monad m => Stream m a -> Stream m (Int, a)
- indexedR :: Monad m => Int -> Stream m a -> Stream m (Int, a)
- zipWithM_ :: Monad m => (a -> b -> m c) -> Stream m a -> Stream m b -> m ()
- zipWithM :: Monad m => (a -> b -> m c) -> Stream m a -> Stream m b -> Stream m c
- zipWith3M :: Monad m => (a -> b -> c -> m d) -> Stream m a -> Stream m b -> Stream m c -> Stream m d
- zipWith4M :: Monad m => (a -> b -> c -> d -> m e) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e
- zipWith5M :: Monad m => (a -> b -> c -> d -> e -> m f) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f
- zipWith6M :: Monad m => (a -> b -> c -> d -> e -> f -> m g) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f -> Stream m g
- zipWith :: Monad m => (a -> b -> c) -> Stream m a -> Stream m b -> Stream m c
- zipWith3 :: Monad m => (a -> b -> c -> d) -> Stream m a -> Stream m b -> Stream m c -> Stream m d
- zipWith4 :: Monad m => (a -> b -> c -> d -> e) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e
- zipWith5 :: Monad m => (a -> b -> c -> d -> e -> f) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f
- zipWith6 :: Monad m => (a -> b -> c -> d -> e -> f -> g) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f -> Stream m g
- zip :: Monad m => Stream m a -> Stream m b -> Stream m (a, b)
- zip3 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m (a, b, c)
- zip4 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m (a, b, c, d)
- zip5 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m (a, b, c, d, e)
- zip6 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f -> Stream m (a, b, c, d, e, f)
- filter :: Monad m => (a -> Bool) -> Stream m a -> Stream m a
- filterM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m a
- takeWhile :: Monad m => (a -> Bool) -> Stream m a -> Stream m a
- takeWhileM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m a
- dropWhile :: Monad m => (a -> Bool) -> Stream m a -> Stream m a
- dropWhileM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m a
- elem :: (Monad m, Eq a) => a -> Stream m a -> m Bool
- notElem :: (Monad m, Eq a) => a -> Stream m a -> m Bool
- find :: Monad m => (a -> Bool) -> Stream m a -> m (Maybe a)
- findM :: Monad m => (a -> m Bool) -> Stream m a -> m (Maybe a)
- findIndex :: Monad m => (a -> Bool) -> Stream m a -> m (Maybe Int)
- findIndexM :: Monad m => (a -> m Bool) -> Stream m a -> m (Maybe Int)
- foldl :: Monad m => (a -> b -> a) -> a -> Stream m b -> m a
- foldlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m a
- foldl1 :: Monad m => (a -> a -> a) -> Stream m a -> m a
- foldl1M :: Monad m => (a -> a -> m a) -> Stream m a -> m a
- foldM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m a
- fold1M :: Monad m => (a -> a -> m a) -> Stream m a -> m a
- foldl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> m a
- foldlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m a
- foldl1' :: Monad m => (a -> a -> a) -> Stream m a -> m a
- foldl1M' :: Monad m => (a -> a -> m a) -> Stream m a -> m a
- foldM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m a
- fold1M' :: Monad m => (a -> a -> m a) -> Stream m a -> m a
- foldr :: Monad m => (a -> b -> b) -> b -> Stream m a -> m b
- foldrM :: Monad m => (a -> b -> m b) -> b -> Stream m a -> m b
- foldr1 :: Monad m => (a -> a -> a) -> Stream m a -> m a
- foldr1M :: Monad m => (a -> a -> m a) -> Stream m a -> m a
- and :: Monad m => Stream m Bool -> m Bool
- or :: Monad m => Stream m Bool -> m Bool
- concatMapM :: Monad m => (a -> m (Stream m b)) -> Stream m a -> Stream m b
- unfoldr :: Monad m => (s -> Maybe (a, s)) -> s -> Stream m a
- unfoldrM :: Monad m => (s -> m (Maybe (a, s))) -> s -> Stream m a
- unfoldrN :: Monad m => Int -> (s -> Maybe (a, s)) -> s -> Stream m a
- unfoldrNM :: Monad m => Int -> (s -> m (Maybe (a, s))) -> s -> Stream m a
- iterateN :: Monad m => Int -> (a -> a) -> a -> Stream m a
- iterateNM :: Monad m => Int -> (a -> m a) -> a -> Stream m a
- prescanl :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m a
- prescanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
- prescanl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m a
- prescanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
- postscanl :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m a
- postscanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
- postscanl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m a
- postscanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
- scanl :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m a
- scanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
- scanl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m a
- scanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m a
- scanl1 :: Monad m => (a -> a -> a) -> Stream m a -> Stream m a
- scanl1M :: Monad m => (a -> a -> m a) -> Stream m a -> Stream m a
- scanl1' :: Monad m => (a -> a -> a) -> Stream m a -> Stream m a
- scanl1M' :: Monad m => (a -> a -> m a) -> Stream m a -> Stream m a
- enumFromStepN :: (Num a, Monad m) => a -> a -> Int -> Stream m a
- enumFromTo :: (Enum a, Monad m) => a -> a -> Stream m a
- enumFromThenTo :: (Enum a, Monad m) => a -> a -> a -> Stream m a
- toList :: Monad m => Stream m a -> m [a]
- fromList :: Monad m => [a] -> Stream m a
- fromListN :: Monad m => Int -> [a] -> Stream m a
- unsafeFromList :: Monad m => Size -> [a] -> Stream m a

# Documentation

Monadic streams

Result of taking a single step in a stream

# Size hints

# Length

# Construction

replicateM :: Monad m => Int -> m a -> Stream m aSource

Yield a `Stream`

of values obtained by performing the monadic action the
given number of times

# Accessing elements

(!?) :: Monad m => Stream m a -> Int -> m (Maybe a)Source

Element at the given position or `Nothing`

if out of bounds

# Substreams

Extract a substream of the given length starting at the given position.

# Mapping

mapM_ :: Monad m => (a -> m b) -> Stream m a -> m ()Source

Execute a monadic action for each element of the `Stream`

trans :: (Monad m, Monad m') => (forall a. m a -> m' a) -> Stream m a -> Stream m' aSource

Transform a `Stream`

to use a different monad

# Zipping

indexed :: Monad m => Stream m a -> Stream m (Int, a)Source

Pair each element in a `Stream`

with its index

indexedR :: Monad m => Int -> Stream m a -> Stream m (Int, a)Source

Pair each element in a `Stream`

with its index, starting from the right
and counting down

zipWithM :: Monad m => (a -> b -> m c) -> Stream m a -> Stream m b -> Stream m cSource

Zip two `Stream`

s with the given monadic function

zipWith3M :: Monad m => (a -> b -> c -> m d) -> Stream m a -> Stream m b -> Stream m c -> Stream m dSource

zipWith4M :: Monad m => (a -> b -> c -> d -> m e) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m eSource

zipWith5M :: Monad m => (a -> b -> c -> d -> e -> m f) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m fSource

zipWith6M :: Monad m => (a -> b -> c -> d -> e -> f -> m g) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f -> Stream m gSource

zipWith3 :: Monad m => (a -> b -> c -> d) -> Stream m a -> Stream m b -> Stream m c -> Stream m dSource

zipWith4 :: Monad m => (a -> b -> c -> d -> e) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m eSource

zipWith5 :: Monad m => (a -> b -> c -> d -> e -> f) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m fSource

zipWith6 :: Monad m => (a -> b -> c -> d -> e -> f -> g) -> Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f -> Stream m gSource

zip4 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m (a, b, c, d)Source

zip5 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m (a, b, c, d, e)Source

zip6 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m d -> Stream m e -> Stream m f -> Stream m (a, b, c, d, e, f)Source

# Filtering

filter :: Monad m => (a -> Bool) -> Stream m a -> Stream m aSource

Drop elements which do not satisfy the predicate

filterM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m aSource

Drop elements which do not satisfy the monadic predicate

takeWhile :: Monad m => (a -> Bool) -> Stream m a -> Stream m aSource

Longest prefix of elements that satisfy the predicate

takeWhileM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m aSource

Longest prefix of elements that satisfy the monadic predicate

dropWhile :: Monad m => (a -> Bool) -> Stream m a -> Stream m aSource

Drop the longest prefix of elements that satisfy the predicate

dropWhileM :: Monad m => (a -> m Bool) -> Stream m a -> Stream m aSource

Drop the longest prefix of elements that satisfy the monadic predicate

# Searching

elem :: (Monad m, Eq a) => a -> Stream m a -> m BoolSource

Check whether the `Stream`

contains an element

# Folding

foldlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m aSource

Left fold with a monadic operator

foldl1M :: Monad m => (a -> a -> m a) -> Stream m a -> m aSource

Left fold over a non-empty `Stream`

with a monadic operator

foldl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> m aSource

Left fold with a strict accumulator

foldlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> m aSource

Left fold with a strict accumulator and a monadic operator

foldl1' :: Monad m => (a -> a -> a) -> Stream m a -> m aSource

Left fold over a non-empty `Stream`

with a strict accumulator

foldl1M' :: Monad m => (a -> a -> m a) -> Stream m a -> m aSource

Left fold over a non-empty `Stream`

with a strict accumulator and a
monadic operator

foldrM :: Monad m => (a -> b -> m b) -> b -> Stream m a -> m bSource

Right fold with a monadic operator

foldr1M :: Monad m => (a -> a -> m a) -> Stream m a -> m aSource

Right fold over a non-empty stream with a monadic operator

# Specialised folds

# Unfolding

unfoldrM :: Monad m => (s -> m (Maybe (a, s))) -> s -> Stream m aSource

Unfold with a monadic function

unfoldrNM :: Monad m => Int -> (s -> m (Maybe (a, s))) -> s -> Stream m aSource

Unfold at most `n`

elements with a monadic functions

iterateN :: Monad m => Int -> (a -> a) -> a -> Stream m aSource

Apply function n times to value. Zeroth element is original value.

iterateNM :: Monad m => Int -> (a -> m a) -> a -> Stream m aSource

Apply monadic function n times to value. Zeroth element is original value.

# Scans

prescanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m aSource

Prefix scan with a monadic operator

prescanl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m aSource

Prefix scan with strict accumulator

prescanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m aSource

Prefix scan with strict accumulator and a monadic operator

postscanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m aSource

Suffix scan with a monadic operator

postscanl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m aSource

Suffix scan with strict accumulator

postscanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m aSource

Suffix scan with strict acccumulator and a monadic operator

scanlM :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m aSource

Haskell-style scan with a monadic operator

scanl' :: Monad m => (a -> b -> a) -> a -> Stream m b -> Stream m aSource

Haskell-style scan with strict accumulator

scanlM' :: Monad m => (a -> b -> m a) -> a -> Stream m b -> Stream m aSource

Haskell-style scan with strict accumulator and a monadic operator

scanl1M :: Monad m => (a -> a -> m a) -> Stream m a -> Stream m aSource

Scan over a non-empty `Stream`

with a monadic operator

scanl1' :: Monad m => (a -> a -> a) -> Stream m a -> Stream m aSource

Scan over a non-empty `Stream`

with a strict accumulator

scanl1M' :: Monad m => (a -> a -> m a) -> Stream m a -> Stream m aSource

Scan over a non-empty `Stream`

with a strict accumulator and a monadic
operator

# Enumerations

enumFromStepN :: (Num a, Monad m) => a -> a -> Int -> Stream m aSource

Yield a `Stream`

of the given length containing the values `x`

, `x+y`

,
`x+y+y`

etc.

enumFromTo :: (Enum a, Monad m) => a -> a -> Stream m aSource

Enumerate values

*WARNING:* This operation can be very inefficient. If at all possible, use
`enumFromStepN`

instead.

enumFromThenTo :: (Enum a, Monad m) => a -> a -> a -> Stream m aSource

Enumerate values with a given step.

*WARNING:* This operation is very inefficient. If at all possible, use
`enumFromStepN`

instead.