Copyright	(c) Roman Leshchinskiy 2008-2010
License	BSD-style
Maintainer	Roman Leshchinskiy <rl@cse.unsw.edu.au>
Stability	experimental
Portability	non-portable
Safe Haskell	None
Language	Haskell98

Data.Vector.Fusion.Stream.Monadic

Contents

Size hints
Length
Construction
Accessing elements
Substreams
Mapping
Zipping
Filtering
Searching
Folding
Specialised folds
Unfolding
Scans
Enumerations
Conversions

Description

Monadic stream combinators.

Synopsis

Documentation

data Stream m a Source

Monadic streams

Constructors

forall s . Stream (s -> m (Step s a)) s Size

Instances

Monad m => Functor (Stream m)
Eq a => Eq (Stream Id a)
Ord a => Ord (Stream Id a)

data Step s a Source

Result of taking a single step in a stream

Constructors

Yield a s	a new element and a new seed
Skip s	just a new seed
Done	end of stream

data SPEC Source

Constructors

SPEC
SPEC2

Size hints

size :: Stream m a -> Size Source

Size hint of a Stream

sized :: Stream m a -> Size -> Stream m a Source

Attach a Size hint to a Stream

Length

length :: Monad m => Stream m a -> m Int Source

Length of a Stream

null :: Monad m => Stream m a -> m Bool Source

Check if a Stream is empty

Construction

empty :: Monad m => Stream m a Source

Empty Stream

singleton :: Monad m => a -> Stream m a Source

Singleton Stream

cons :: Monad m => a -> Stream m a -> Stream m a Source

Prepend an element

snoc :: Monad m => Stream m a -> a -> Stream m a Source

Append an element

replicate :: Monad m => Int -> a -> Stream m a Source

Replicate a value to a given length

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

Yield a Stream of values obtained by performing the monadic action the given number of times

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

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

Generate a stream from its indices

(++) :: Monad m => Stream m a -> Stream m a -> Stream m a infixr 5 Source

Concatenate two Streams

Accessing elements

head :: Monad m => Stream m a -> m a Source

First element of the Stream or error if empty

last :: Monad m => Stream m a -> m a Source

Last element of the Stream or error if empty

(!!) :: Monad m => Stream m a -> Int -> m a infixl 9 Source

Element at the given position

(!?) :: Monad m => Stream m a -> Int -> m (Maybe a) infixl 9 Source

Element at the given position or Nothing if out of bounds

Substreams

slice Source

Arguments

:: Monad m
=> Int	starting index
-> Int	length
-> Stream m a
-> Stream m a

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

init :: Monad m => Stream m a -> Stream m a Source

All but the last element

tail :: Monad m => Stream m a -> Stream m a Source

All but the first element

take :: Monad m => Int -> Stream m a -> Stream m a Source

The first n elements

drop :: Monad m => Int -> Stream m a -> Stream m a Source

All but the first n elements

Mapping

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

Map a function over a Stream

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

Map a monadic function over a Stream

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' a Source

Transform a Stream to use a different monad

unbox :: Monad m => Stream m (Box a) -> Stream m a Source

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

flatten :: Monad m => (a -> m s) -> (s -> m (Step s b)) -> Size -> Stream m a -> Stream m b Source

Create a Stream of values from a Stream of streamable things

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 -> m () Source

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

Zip two Streams with the given monadic function

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

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

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 Source

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 Source

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

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

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

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 Source

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 Source

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

zip3 :: Monad m => Stream m a -> Stream m b -> Stream m c -> Stream m (a, b, c) Source

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 a Source

Drop elements which do not satisfy the predicate

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

Drop elements which do not satisfy the monadic predicate

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

Longest prefix of elements that satisfy the predicate

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

Longest prefix of elements that satisfy the monadic predicate

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

Drop the longest prefix of elements that satisfy the predicate

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

Drop the longest prefix of elements that satisfy the monadic predicate

Searching

elem :: (Monad m, Eq a) => a -> Stream m a -> m Bool infix 4 Source

Check whether the Stream contains an element

notElem :: (Monad m, Eq a) => a -> Stream m a -> m Bool infix 4 Source

Inverse of elem

find :: Monad m => (a -> Bool) -> Stream m a -> m (Maybe a) Source

Yield Just the first element that satisfies the predicate or Nothing if no such element exists.

findM :: Monad m => (a -> m Bool) -> Stream m a -> m (Maybe a) Source

Yield Just the first element that satisfies the monadic predicate or Nothing if no such element exists.

findIndex :: Monad m => (a -> Bool) -> Stream m a -> m (Maybe Int) Source

Yield Just the index of the first element that satisfies the predicate or Nothing if no such element exists.

findIndexM :: Monad m => (a -> m Bool) -> Stream m a -> m (Maybe Int) Source

Yield Just the index of the first element that satisfies the monadic predicate or Nothing if no such element exists.

Folding

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

Left fold

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

Left fold with a monadic operator

foldl1 :: Monad m => (a -> a -> a) -> Stream m a -> m a Source

Left fold over a non-empty Stream

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

Left fold over a non-empty Stream with a monadic operator

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

Same as foldlM

fold1M :: Monad m => (a -> a -> m a) -> Stream m a -> m a Source

Same as foldl1M

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

Left fold with a strict accumulator

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

Left fold with a strict accumulator and a monadic operator

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

Left fold over a non-empty Stream with a strict accumulator

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

Left fold over a non-empty Stream with a strict accumulator and a monadic operator

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

Same as foldlM'

fold1M' :: Monad m => (a -> a -> m a) -> Stream m a -> m a Source

Same as foldl1M'

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

Right fold

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

Right fold with a monadic operator

foldr1 :: Monad m => (a -> a -> a) -> Stream m a -> m a Source

Right fold over a non-empty stream

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

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

Specialised folds

and :: Monad m => Stream m Bool -> m Bool Source

or :: Monad m => Stream m Bool -> m Bool Source

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

Unfolding

unfoldr :: Monad m => (s -> Maybe (a, s)) -> s -> Stream m a Source

Unfold

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

Unfold with a monadic function

unfoldrN :: Monad m => Int -> (s -> Maybe (a, s)) -> s -> Stream m a Source

Unfold at most n elements

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

Unfold at most n elements with a monadic functions

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

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

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

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

Scans

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

Prefix scan

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

Prefix scan with a monadic operator

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

Prefix scan with strict accumulator

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

Prefix scan with strict accumulator and a monadic operator

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

Suffix scan

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

Suffix scan with a monadic operator

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

Suffix scan with strict accumulator

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

Suffix scan with strict acccumulator and a monadic operator

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

Haskell-style scan

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

Haskell-style scan with a monadic operator

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

Haskell-style scan with strict accumulator

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

Haskell-style scan with strict accumulator and a monadic operator

scanl1 :: Monad m => (a -> a -> a) -> Stream m a -> Stream m a Source

Scan over a non-empty Stream

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

Scan over a non-empty Stream with a monadic operator

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

Scan over a non-empty Stream with a strict accumulator

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

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 a Source

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 a Source

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 a Source

Enumerate values with a given step.

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

Conversions

toList :: Monad m => Stream m a -> m [a] Source

Convert a Stream to a list

fromList :: Monad m => [a] -> Stream m a Source

Convert a list to a Stream

fromListN :: Monad m => Int -> [a] -> Stream m a Source

Convert the first n elements of a list to a Stream

unsafeFromList :: Monad m => Size -> [a] -> Stream m a Source

Convert a list to a Stream with the given Size hint.