Data.Vector

A library for boxed vectors (that is, polymorphic arrays capable of holding any Haskell value). The vectors come in two flavours:

• mutable
• immutable

and support a rich interface of both list-like operations, and bulk array operations.

For unboxed arrays, use Data.Vector.Unboxed

Boxed vectors

data Vector a

Boxed vectors, supporting efficient slicing.

Instances

Monad Vector

Defined in Data.Vector

Methods

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

(>>) :: Vector a -> Vector b -> Vector b

return :: a -> Vector a

Functor Vector

Defined in Data.Vector

Methods

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

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

MonadFix Vector

Instance has same semantics as one for lists

Since: 0.12.2.0

Defined in Data.Vector

Methods

mfix :: (a -> Vector a) -> Vector a

MonadFail Vector

Since: 0.12.1.0

Defined in Data.Vector

Methods

fail :: String -> Vector a

Applicative Vector

Defined in Data.Vector

Methods

pure :: a -> Vector a

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

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

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

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

Foldable Vector

Defined in Data.Vector

Methods

fold :: Monoid m => Vector m -> m

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

foldMap' :: Monoid m => (a -> m) -> Vector a -> m

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

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

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

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

foldr1 :: (a -> a -> a) -> Vector a -> a

foldl1 :: (a -> a -> a) -> Vector a -> a

toList :: Vector a -> [a]

null :: Vector a -> Bool

length :: Vector a -> Int

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

maximum :: Ord a => Vector a -> a

minimum :: Ord a => Vector a -> a

sum :: Num a => Vector a -> a

product :: Num a => Vector a -> a

Traversable Vector

Defined in Data.Vector

Methods

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

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

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

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

Eq1 Vector

Defined in Data.Vector

Methods

liftEq :: (a -> b -> Bool) -> Vector a -> Vector b -> Bool

Ord1 Vector

Defined in Data.Vector

Methods

liftCompare :: (a -> b -> Ordering) -> Vector a -> Vector b -> Ordering

Read1 Vector

Defined in Data.Vector

Methods

liftReadsPrec :: (Int -> ReadS a) -> ReadS [a] -> Int -> ReadS (Vector a)

liftReadList :: (Int -> ReadS a) -> ReadS [a] -> ReadS [Vector a]

liftReadPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec (Vector a)

liftReadListPrec :: ReadPrec a -> ReadPrec [a] -> ReadPrec [Vector a]

Show1 Vector

Defined in Data.Vector

Methods

liftShowsPrec :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> Int -> Vector a -> ShowS

liftShowList :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> [Vector a] -> ShowS

MonadZip Vector

Defined in Data.Vector

Methods

mzip :: Vector a -> Vector b -> Vector (a, b)

mzipWith :: (a -> b -> c) -> Vector a -> Vector b -> Vector c

munzip :: Vector (a, b) -> (Vector a, Vector b)

Alternative Vector

Defined in Data.Vector

Methods

empty :: Vector a

(<|>) :: Vector a -> Vector a -> Vector a

some :: Vector a -> Vector [a]

many :: Vector a -> Vector [a]

MonadPlus Vector

Defined in Data.Vector

Methods

mzero :: Vector a

mplus :: Vector a -> Vector a -> Vector a

NFData1 Vector

Since: 0.12.1.0

Defined in Data.Vector

Methods

liftRnf :: (a -> ()) -> Vector a -> ()

Vector Vector a

Defined in Data.Vector

Methods

basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) a -> m (Vector a)

basicUnsafeThaw :: PrimMonad m => Vector a -> m (Mutable Vector (PrimState m) a)

basicLength :: Vector a -> Int

basicUnsafeSlice :: Int -> Int -> Vector a -> Vector a

basicUnsafeIndexM :: Monad m => Vector a -> Int -> m a

basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) a -> Vector a -> m ()

elemseq :: Vector a -> a -> b -> b

IsList (Vector a)

Defined in Data.Vector

Associated Types

type Item (Vector a)

Methods

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

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

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

Eq a => Eq (Vector a)

Defined in Data.Vector

Methods

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

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

Data a => Data (Vector a)

Defined in Data.Vector

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Vector a -> c (Vector a)

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Vector a)

toConstr :: Vector a -> Constr

dataTypeOf :: Vector a -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Vector a))

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Vector a))

gmapT :: (forall b. Data b => b -> b) -> Vector a -> Vector a

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Vector a -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Vector a -> r

gmapQ :: (forall d. Data d => d -> u) -> Vector a -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> Vector a -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Vector a -> m (Vector a)

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Vector a -> m (Vector a)

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Vector a -> m (Vector a)

Ord a => Ord (Vector a)

Defined in Data.Vector

Methods

compare :: Vector a -> Vector a -> Ordering

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

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

(>) :: Vector a -> Vector a -> Bool

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

max :: Vector a -> Vector a -> Vector a

min :: Vector a -> Vector a -> Vector a

Read a => Read (Vector a)

Defined in Data.Vector

Methods

readsPrec :: Int -> ReadS (Vector a)

readList :: ReadS [Vector a]

readPrec :: ReadPrec (Vector a)

readListPrec :: ReadPrec [Vector a]

Show a => Show (Vector a)

Defined in Data.Vector

Methods

showsPrec :: Int -> Vector a -> ShowS

show :: Vector a -> String

showList :: [Vector a] -> ShowS

Semigroup (Vector a)

Defined in Data.Vector

Methods

(<>) :: Vector a -> Vector a -> Vector a

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

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

Monoid (Vector a)

Defined in Data.Vector

Methods

mempty :: Vector a

mappend :: Vector a -> Vector a -> Vector a

mconcat :: [Vector a] -> Vector a

NFData a => NFData (Vector a)

Defined in Data.Vector

Methods

rnf :: Vector a -> ()

type Mutable Vector

Defined in Data.Vector

type Mutable Vector = MVector

type Item (Vector a)

Defined in Data.Vector

type Item (Vector a) = a

data MVector s a

Mutable boxed vectors keyed on the monad they live in (IO or ST s).

Instances

MVector MVector a

Defined in Data.Vector.Mutable

Methods

basicLength :: MVector s a -> Int

basicUnsafeSlice :: Int -> Int -> MVector s a -> MVector s a

basicOverlaps :: MVector s a -> MVector s a -> Bool

basicUnsafeNew :: PrimMonad m => Int -> m (MVector (PrimState m) a)

basicInitialize :: PrimMonad m => MVector (PrimState m) a -> m ()

basicUnsafeReplicate :: PrimMonad m => Int -> a -> m (MVector (PrimState m) a)

basicUnsafeRead :: PrimMonad m => MVector (PrimState m) a -> Int -> m a

basicUnsafeWrite :: PrimMonad m => MVector (PrimState m) a -> Int -> a -> m ()

basicClear :: PrimMonad m => MVector (PrimState m) a -> m ()

basicSet :: PrimMonad m => MVector (PrimState m) a -> a -> m ()

basicUnsafeCopy :: PrimMonad m => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()

basicUnsafeMove :: PrimMonad m => MVector (PrimState m) a -> MVector (PrimState m) a -> m ()

basicUnsafeGrow :: PrimMonad m => MVector (PrimState m) a -> Int -> m (MVector (PrimState m) a)

Accessors

Length information

length :: Vector a -> Int

O(1) Yield the length of the vector

null :: Vector a -> Bool

O(1) Test whether a vector is empty

Indexing

(!) :: Vector a -> Int -> a

O(1) Indexing

(!?) :: Vector a -> Int -> Maybe a

O(1) Safe indexing

head :: Vector a -> a

O(1) First element

last :: Vector a -> a

O(1) Last element

unsafeIndex :: Vector a -> Int -> a

O(1) Unsafe indexing without bounds checking

unsafeHead :: Vector a -> a

O(1) First element without checking if the vector is empty

unsafeLast :: Vector a -> a

O(1) Last element without checking if the vector is empty

Monadic indexing

indexM :: Monad m => Vector a -> Int -> m a

O(1) Indexing in a monad.

The monad allows operations to be strict in the vector when necessary. Suppose vector copying is implemented like this:

copy mv v = ... write mv i (v ! i) ...

For lazy vectors, v ! i would not be evaluated which means that mv would unnecessarily retain a reference to v in each element written.

With indexM, copying can be implemented like this instead:

copy mv v = ... do
                  x <- indexM v i
                  write mv i x

Here, no references to v are retained because indexing (but not the elements) is evaluated eagerly.

headM :: Monad m => Vector a -> m a

O(1) First element of a vector in a monad. See indexM for an explanation of why this is useful.

lastM :: Monad m => Vector a -> m a

O(1) Last element of a vector in a monad. See indexM for an explanation of why this is useful.

unsafeIndexM :: Monad m => Vector a -> Int -> m a

O(1) Indexing in a monad without bounds checks. See indexM for an explanation of why this is useful.

unsafeHeadM :: Monad m => Vector a -> m a

O(1) First element in a monad without checking for empty vectors. See indexM for an explanation of why this is useful.

unsafeLastM :: Monad m => Vector a -> m a

O(1) Last element in a monad without checking for empty vectors. See indexM for an explanation of why this is useful.

Extracting subvectors (slicing)

slice

Arguments

:: Int

i starting index

-> Int

n length

-> Vector a

-> Vector a

O(1) Yield a slice of the vector without copying it. The vector must contain at least i+n elements.

init :: Vector a -> Vector a

O(1) Yield all but the last element without copying. The vector may not be empty.

tail :: Vector a -> Vector a

O(1) Yield all but the first element without copying. The vector may not be empty.

take :: Int -> Vector a -> Vector a

O(1) Yield at the first n elements without copying. The vector may contain less than n elements in which case it is returned unchanged.

drop :: Int -> Vector a -> Vector a

O(1) Yield all but the first n elements without copying. The vector may contain less than n elements in which case an empty vector is returned.

splitAt :: Int -> Vector a -> (Vector a, Vector a)

O(1) Yield the first n elements paired with the remainder without copying.

Note that splitAt n v is equivalent to (take n v, drop n v) but slightly more efficient.

Since: 0.7.1

uncons :: Vector a -> Maybe (a, Vector a)

O(1) Yield the head and tail of the vector, or Nothing if empty.

Since: 0.12.2.0

unsnoc :: Vector a -> Maybe (Vector a, a)

O(1) Yield the last and init of the vector, or Nothing if empty.

Since: 0.12.2.0

unsafeSlice

Arguments

:: Int

i starting index

-> Int

n length

-> Vector a

-> Vector a

O(1) Yield a slice of the vector without copying. The vector must contain at least i+n elements but this is not checked.

unsafeInit :: Vector a -> Vector a

O(1) Yield all but the last element without copying. The vector may not be empty but this is not checked.

unsafeTail :: Vector a -> Vector a

O(1) Yield all but the first element without copying. The vector may not be empty but this is not checked.

unsafeTake :: Int -> Vector a -> Vector a

O(1) Yield the first n elements without copying. The vector must contain at least n elements but this is not checked.

unsafeDrop :: Int -> Vector a -> Vector a

O(1) Yield all but the first n elements without copying. The vector must contain at least n elements but this is not checked.

Construction

Initialisation

empty :: Vector a

O(1) Empty vector

singleton :: a -> Vector a

O(1) Vector with exactly one element

replicate :: Int -> a -> Vector a

O(n) Vector of the given length with the same value in each position

generate :: Int -> (Int -> a) -> Vector a

O(n) Construct a vector of the given length by applying the function to each index

iterateN :: Int -> (a -> a) -> a -> Vector a

O(n) Apply function \(\max(n - 1, 0)\) times to an initial value, producing a vector of length \(\max(n, 0)\). Zeroth element will contain the initial value, that's why there is one less function application than the number of elements in the produced vector.

\( \underbrace{x, f (x), f (f (x)), \ldots}_{\max(0,n)\rm{~elements}} \)

Examples

>>> import qualified Data.Vector as V
>>> V.iterateN 0 undefined undefined :: V.Vector String
[]
>>> V.iterateN 4 (\x -> x <> x) "Hi"
["Hi","HiHi","HiHiHiHi","HiHiHiHiHiHiHiHi"]

Since: 0.7.1

Monadic initialisation

replicateM :: Monad m => Int -> m a -> m (Vector a)

O(n) Execute the monadic action the given number of times and store the results in a vector.

generateM :: Monad m => Int -> (Int -> m a) -> m (Vector a)

O(n) Construct a vector of the given length by applying the monadic action to each index

iterateNM :: Monad m => Int -> (a -> m a) -> a -> m (Vector a)

O(n) Apply monadic function \(\max(n - 1, 0)\) times to an initial value, producing a vector of length \(\max(n, 0)\). Zeroth element will contain the initial value, that's why there is one less function application than the number of elements in the produced vector.

For non-monadic version see iterateN

Since: 0.12.0.0

create :: (forall s. ST s (MVector s a)) -> Vector a

Execute the monadic action and freeze the resulting vector.

create (do { v <- new 2; write v 0 'a'; write v 1 'b'; return v }) = <a,b>

createT :: Traversable f => (forall s. ST s (f (MVector s a))) -> f (Vector a)

Execute the monadic action and freeze the resulting vectors.

Unfolding

unfoldr :: (b -> Maybe (a, b)) -> b -> Vector a

O(n) Construct a vector by repeatedly applying the generator function to a seed. The generator function yields Just the next element and the new seed or Nothing if there are no more elements.

unfoldr (\n -> if n == 0 then Nothing else Just (n,n-1)) 10
 = <10,9,8,7,6,5,4,3,2,1>

unfoldrN :: Int -> (b -> Maybe (a, b)) -> b -> Vector a

O(n) Construct a vector with at most n elements by repeatedly applying the generator function to a seed. The generator function yields Just the next element and the new seed or Nothing if there are no more elements.

unfoldrN 3 (\n -> Just (n,n-1)) 10 = <10,9,8>

unfoldrExactN :: Int -> (b -> (a, b)) -> b -> Vector a

O(n) Construct a vector with exactly n elements by repeatedly applying the generator function to a seed. The generator function yields the next element and the new seed.

unfoldrExactN 3 (\n -> (n,n-1)) 10 = <10,9,8>

Since: 0.12.2.0

unfoldrM :: Monad m => (b -> m (Maybe (a, b))) -> b -> m (Vector a)

O(n) Construct a vector by repeatedly applying the monadic generator function to a seed. The generator function yields Just the next element and the new seed or Nothing if there are no more elements.

unfoldrNM :: Monad m => Int -> (b -> m (Maybe (a, b))) -> b -> m (Vector a)

O(n) Construct a vector by repeatedly applying the monadic generator function to a seed. The generator function yields Just the next element and the new seed or Nothing if there are no more elements.

unfoldrExactNM :: Monad m => Int -> (b -> m (a, b)) -> b -> m (Vector a)

O(n) Construct a vector with exactly n elements by repeatedly applying the monadic generator function to a seed. The generator function yields the next element and the new seed.

Since: 0.12.2.0

constructN :: Int -> (Vector a -> a) -> Vector a

O(n) Construct a vector with n elements by repeatedly applying the generator function to the already constructed part of the vector.

constructN 3 f = let a = f <> ; b = f <a> ; c = f <a,b> in <a,b,c>

constructrN :: Int -> (Vector a -> a) -> Vector a

O(n) Construct a vector with n elements from right to left by repeatedly applying the generator function to the already constructed part of the vector.

constructrN 3 f = let a = f <> ; b = f<a> ; c = f <b,a> in <c,b,a>

Enumeration

enumFromN :: Num a => a -> Int -> Vector a

O(n) Yield a vector of the given length containing the values x, x+1 etc. This operation is usually more efficient than enumFromTo.

enumFromN 5 3 = <5,6,7>

enumFromStepN :: Num a => a -> a -> Int -> Vector a

O(n) Yield a vector of the given length containing the values x, x+y, x+y+y etc. This operations is usually more efficient than enumFromThenTo.

enumFromStepN 1 0.1 5 = <1,1.1,1.2,1.3,1.4>

enumFromTo :: Enum a => a -> a -> Vector a

O(n) Enumerate values from x to y.

WARNING: This operation can be very inefficient. If at all possible, use enumFromN instead.

enumFromThenTo :: Enum a => a -> a -> a -> Vector a

O(n) Enumerate values from x to y with a specific step z.

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

Concatenation

cons :: a -> Vector a -> Vector a

O(n) Prepend an element

snoc :: Vector a -> a -> Vector a

O(n) Append an element

(++) :: Vector a -> Vector a -> Vector a infixr 5

O(m+n) Concatenate two vectors

concat :: [Vector a] -> Vector a

O(n) Concatenate all vectors in the list

Restricting memory usage

force :: Vector a -> Vector a

O(n) Yield the argument but force it not to retain any extra memory, possibly by copying it.

This is especially useful when dealing with slices. For example:

force (slice 0 2 <huge vector>)

Here, the slice retains a reference to the huge vector. Forcing it creates a copy of just the elements that belong to the slice and allows the huge vector to be garbage collected.

Modifying vectors

Bulk updates

(//)

Arguments

:: Vector a

initial vector (of length m)

-> [(Int, a)]

list of index/value pairs (of length n)

-> Vector a

O(m+n) For each pair (i,a) from the list, replace the vector element at position i by a.

<5,9,2,7> // [(2,1),(0,3),(2,8)] = <3,9,8,7>

update

Arguments

:: Vector a

initial vector (of length m)

-> Vector (Int, a)

vector of index/value pairs (of length n)

-> Vector a

O(m+n) For each pair (i,a) from the vector of index/value pairs, replace the vector element at position i by a.

update <5,9,2,7> <(2,1),(0,3),(2,8)> = <3,9,8,7>

update_

Arguments

:: Vector a

initial vector (of length m)

-> Vector Int

index vector (of length n1)

-> Vector a

value vector (of length n2)

-> Vector a

O(m+min(n1,n2)) For each index i from the index vector and the corresponding value a from the value vector, replace the element of the initial vector at position i by a.

update_ <5,9,2,7>  <2,0,2> <1,3,8> = <3,9,8,7>

The function update provides the same functionality and is usually more convenient.

update_ xs is ys = update xs (zip is ys)

unsafeUpd :: Vector a -> [(Int, a)] -> Vector a

Same as (//) but without bounds checking.

unsafeUpdate :: Vector a -> Vector (Int, a) -> Vector a

Same as update but without bounds checking.

unsafeUpdate_ :: Vector a -> Vector Int -> Vector a -> Vector a

Same as update_ but without bounds checking.

Accumulations

accum

Arguments

:: (a -> b -> a)

accumulating function f

-> Vector a

initial vector (of length m)

-> [(Int, b)]

list of index/value pairs (of length n)

-> Vector a

O(m+n) For each pair (i,b) from the list, replace the vector element a at position i by f a b.

Examples

>>> import qualified Data.Vector as V
>>> V.accum (+) (V.fromList [1000.0,2000.0,3000.0]) [(2,4),(1,6),(0,3),(1,10)]
[1003.0,2016.0,3004.0]

accumulate

Arguments

:: (a -> b -> a)

accumulating function f

-> Vector a

initial vector (of length m)

-> Vector (Int, b)

vector of index/value pairs (of length n)

-> Vector a

O(m+n) For each pair (i,b) from the vector of pairs, replace the vector element a at position i by f a b.

Examples

>>> import qualified Data.Vector as V
>>> V.accumulate (+) (V.fromList [1000.0,2000.0,3000.0]) (V.fromList [(2,4),(1,6),(0,3),(1,10)])
[1003.0,2016.0,3004.0]

accumulate_

Arguments

:: (a -> b -> a)

accumulating function f

-> Vector a

initial vector (of length m)

-> Vector Int

index vector (of length n1)

-> Vector b

value vector (of length n2)

-> Vector a

O(m+min(n1,n2)) For each index i from the index vector and the corresponding value b from the the value vector, replace the element of the initial vector at position i by f a b.

accumulate_ (+) <5,9,2> <2,1,0,1> <4,6,3,7> = <5+3, 9+6+7, 2+4>

The function accumulate provides the same functionality and is usually more convenient.

accumulate_ f as is bs = accumulate f as (zip is bs)

unsafeAccum :: (a -> b -> a) -> Vector a -> [(Int, b)] -> Vector a

Same as accum but without bounds checking.

unsafeAccumulate :: (a -> b -> a) -> Vector a -> Vector (Int, b) -> Vector a

Same as accumulate but without bounds checking.

unsafeAccumulate_ :: (a -> b -> a) -> Vector a -> Vector Int -> Vector b -> Vector a

Same as accumulate_ but without bounds checking.

Permutations

reverse :: Vector a -> Vector a

O(n) Reverse a vector

backpermute :: Vector a -> Vector Int -> Vector a

O(n) Yield the vector obtained by replacing each element i of the index vector by xs!i. This is equivalent to map (xs!) is but is often much more efficient.

backpermute <a,b,c,d> <0,3,2,3,1,0> = <a,d,c,d,b,a>

unsafeBackpermute :: Vector a -> Vector Int -> Vector a

Same as backpermute but without bounds checking.

Safe destructive updates

modify :: (forall s. MVector s a -> ST s ()) -> Vector a -> Vector a

Apply a destructive operation to a vector. The operation will be performed in place if it is safe to do so and will modify a copy of the vector otherwise.

modify (\v -> write v 0 'x') (replicate 3 'a') = <'x','a','a'>

Elementwise operations

Indexing

indexed :: Vector a -> Vector (Int, a)

O(n) Pair each element in a vector with its index

Mapping

map :: (a -> b) -> Vector a -> Vector b

O(n) Map a function over a vector

imap :: (Int -> a -> b) -> Vector a -> Vector b

O(n) Apply a function to every element of a vector and its index

concatMap :: (a -> Vector b) -> Vector a -> Vector b

Map a function over a vector and concatenate the results.

Monadic mapping

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

O(n) Apply the monadic action to all elements of the vector, yielding a vector of results

imapM :: Monad m => (Int -> a -> m b) -> Vector a -> m (Vector b)

O(n) Apply the monadic action to every element of a vector and its index, yielding a vector of results

mapM_ :: Monad m => (a -> m b) -> Vector a -> m ()

O(n) Apply the monadic action to all elements of a vector and ignore the results

imapM_ :: Monad m => (Int -> a -> m b) -> Vector a -> m ()

O(n) Apply the monadic action to every element of a vector and its index, ignoring the results

forM :: Monad m => Vector a -> (a -> m b) -> m (Vector b)

O(n) Apply the monadic action to all elements of the vector, yielding a vector of results. Equivalent to flip mapM.

forM_ :: Monad m => Vector a -> (a -> m b) -> m ()

O(n) Apply the monadic action to all elements of a vector and ignore the results. Equivalent to flip mapM_.

iforM :: Monad m => Vector a -> (Int -> a -> m b) -> m (Vector b)

O(n) Apply the monadic action to all elements of the vector and their indices, yielding a vector of results. Equivalent to flip imapM.

Since: 0.12.2.0

iforM_ :: Monad m => Vector a -> (Int -> a -> m b) -> m ()

O(n) Apply the monadic action to all elements of the vector and their indices and ignore the results. Equivalent to flip imapM_.

Since: 0.12.2.0

Zipping

zipWith :: (a -> b -> c) -> Vector a -> Vector b -> Vector c

O(min(m,n)) Zip two vectors with the given function.

zipWith3 :: (a -> b -> c -> d) -> Vector a -> Vector b -> Vector c -> Vector d

Zip three vectors with the given function.

zipWith4 :: (a -> b -> c -> d -> e) -> Vector a -> Vector b -> Vector c -> Vector d -> Vector e

zipWith5 :: (a -> b -> c -> d -> e -> f) -> Vector a -> Vector b -> Vector c -> Vector d -> Vector e -> Vector f

zipWith6 :: (a -> b -> c -> d -> e -> f -> g) -> Vector a -> Vector b -> Vector c -> Vector d -> Vector e -> Vector f -> Vector g

izipWith :: (Int -> a -> b -> c) -> Vector a -> Vector b -> Vector c

O(min(m,n)) Zip two vectors with a function that also takes the elements' indices.

izipWith3 :: (Int -> a -> b -> c -> d) -> Vector a -> Vector b -> Vector c -> Vector d

Zip three vectors and their indices with the given function.

izipWith4 :: (Int -> a -> b -> c -> d -> e) -> Vector a -> Vector b -> Vector c -> Vector d -> Vector e

izipWith5 :: (Int -> a -> b -> c -> d -> e -> f) -> Vector a -> Vector b -> Vector c -> Vector d -> Vector e -> Vector f

izipWith6 :: (Int -> a -> b -> c -> d -> e -> f -> g) -> Vector a -> Vector b -> Vector c -> Vector d -> Vector e -> Vector f -> Vector g

zip :: Vector a -> Vector b -> Vector (a, b)

Elementwise pairing of array elements.

zip3 :: Vector a -> Vector b -> Vector c -> Vector (a, b, c)

zip together three vectors into a vector of triples

zip4 :: Vector a -> Vector b -> Vector c -> Vector d -> Vector (a, b, c, d)

zip5 :: Vector a -> Vector b -> Vector c -> Vector d -> Vector e -> Vector (a, b, c, d, e)

zip6 :: Vector a -> Vector b -> Vector c -> Vector d -> Vector e -> Vector f -> Vector (a, b, c, d, e, f)

Monadic zipping

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

O(min(m,n)) Zip the two vectors with the monadic action and yield a vector of results

izipWithM :: Monad m => (Int -> a -> b -> m c) -> Vector a -> Vector b -> m (Vector c)

O(min(m,n)) Zip the two vectors with a monadic action that also takes the element index and yield a vector of results

zipWithM_ :: Monad m => (a -> b -> m c) -> Vector a -> Vector b -> m ()

O(min(m,n)) Zip the two vectors with the monadic action and ignore the results

izipWithM_ :: Monad m => (Int -> a -> b -> m c) -> Vector a -> Vector b -> m ()

O(min(m,n)) Zip the two vectors with a monadic action that also takes the element index and ignore the results

Unzipping

unzip :: Vector (a, b) -> (Vector a, Vector b)

O(min(m,n)) Unzip a vector of pairs.

unzip3 :: Vector (a, b, c) -> (Vector a, Vector b, Vector c)

unzip4 :: Vector (a, b, c, d) -> (Vector a, Vector b, Vector c, Vector d)

unzip5 :: Vector (a, b, c, d, e) -> (Vector a, Vector b, Vector c, Vector d, Vector e)

unzip6 :: Vector (a, b, c, d, e, f) -> (Vector a, Vector b, Vector c, Vector d, Vector e, Vector f)

Working with predicates

Filtering

filter :: (a -> Bool) -> Vector a -> Vector a

O(n) Drop elements that do not satisfy the predicate

ifilter :: (Int -> a -> Bool) -> Vector a -> Vector a

O(n) Drop elements that do not satisfy the predicate which is applied to values and their indices

filterM :: Monad m => (a -> m Bool) -> Vector a -> m (Vector a)

O(n) Drop elements that do not satisfy the monadic predicate

uniq :: Eq a => Vector a -> Vector a

O(n) Drop repeated adjacent elements.

mapMaybe :: (a -> Maybe b) -> Vector a -> Vector b

O(n) Drop elements when predicate returns Nothing

imapMaybe :: (Int -> a -> Maybe b) -> Vector a -> Vector b

O(n) Drop elements when predicate, applied to index and value, returns Nothing

mapMaybeM :: Monad m => (a -> m (Maybe b)) -> Vector a -> m (Vector b)

O(n) Apply monadic function to each element of vector and discard elements returning Nothing.

Since: 0.12.2.0

imapMaybeM :: Monad m => (Int -> a -> m (Maybe b)) -> Vector a -> m (Vector b)

O(n) Apply monadic function to each element of vector and its index. Discards elements returning Nothing.

Since: 0.12.2.0

catMaybes :: Vector (Maybe a) -> Vector a

O(n) Return a Vector of all the Just values.

Since: 0.12.2.0

takeWhile :: (a -> Bool) -> Vector a -> Vector a

O(n) Yield the longest prefix of elements satisfying the predicate. Current implementation is not copy-free, unless the result vector is fused away.

dropWhile :: (a -> Bool) -> Vector a -> Vector a

O(n) Drop the longest prefix of elements that satisfy the predicate without copying.

Partitioning

partition :: (a -> Bool) -> Vector a -> (Vector a, Vector a)

O(n) Split the vector in two parts, the first one containing those elements that satisfy the predicate and the second one those that don't. The relative order of the elements is preserved at the cost of a sometimes reduced performance compared to unstablePartition.

unstablePartition :: (a -> Bool) -> Vector a -> (Vector a, Vector a)

O(n) Split the vector in two parts, the first one containing those elements that satisfy the predicate and the second one those that don't. The order of the elements is not preserved but the operation is often faster than partition.

partitionWith :: (a -> Either b c) -> Vector a -> (Vector b, Vector c)

O(n) Split the vector into two parts, the first one containing the Left elements and the second containing the Right elements. The relative order of the elements is preserved.

Since: 0.12.1.0

span :: (a -> Bool) -> Vector a -> (Vector a, Vector a)

O(n) Split the vector into the longest prefix of elements that satisfy the predicate and the rest without copying.

break :: (a -> Bool) -> Vector a -> (Vector a, Vector a)

O(n) Split the vector into the longest prefix of elements that do not satisfy the predicate and the rest without copying.

Searching

elem :: Eq a => a -> Vector a -> Bool infix 4

O(n) Check if the vector contains an element

notElem :: Eq a => a -> Vector a -> Bool infix 4

O(n) Check if the vector does not contain an element (inverse of elem)

find :: (a -> Bool) -> Vector a -> Maybe a

O(n) Yield Just the first element matching the predicate or Nothing if no such element exists.

findIndex :: (a -> Bool) -> Vector a -> Maybe Int

O(n) Yield Just the index of the first element matching the predicate or Nothing if no such element exists.

findIndices :: (a -> Bool) -> Vector a -> Vector Int

O(n) Yield the indices of elements satisfying the predicate in ascending order.

elemIndex :: Eq a => a -> Vector a -> Maybe Int

O(n) Yield Just the index of the first occurence of the given element or Nothing if the vector does not contain the element. This is a specialised version of findIndex.

elemIndices :: Eq a => a -> Vector a -> Vector Int

O(n) Yield the indices of all occurences of the given element in ascending order. This is a specialised version of findIndices.

Folding

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

O(n) Left fold

foldl1 :: (a -> a -> a) -> Vector a -> a

O(n) Left fold on non-empty vectors

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

O(n) Left fold with strict accumulator

foldl1' :: (a -> a -> a) -> Vector a -> a

O(n) Left fold on non-empty vectors with strict accumulator

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

O(n) Right fold

foldr1 :: (a -> a -> a) -> Vector a -> a

O(n) Right fold on non-empty vectors

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

O(n) Right fold with a strict accumulator

foldr1' :: (a -> a -> a) -> Vector a -> a

O(n) Right fold on non-empty vectors with strict accumulator

ifoldl :: (a -> Int -> b -> a) -> a -> Vector b -> a

O(n) Left fold (function applied to each element and its index)

ifoldl' :: (a -> Int -> b -> a) -> a -> Vector b -> a

O(n) Left fold with strict accumulator (function applied to each element and its index)

ifoldr :: (Int -> a -> b -> b) -> b -> Vector a -> b

O(n) Right fold (function applied to each element and its index)

ifoldr' :: (Int -> a -> b -> b) -> b -> Vector a -> b

O(n) Right fold with strict accumulator (function applied to each element and its index)

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

O(n) Map each element of the structure to a monoid, and combine the results. It uses same implementation as corresponding method of Foldable type cless. Note it's implemented in terms of foldr and won't fuse with functions that traverse vector from left to right (map, generate, etc.).

Since: 0.12.2.0

foldMap' :: Monoid m => (a -> m) -> Vector a -> m

O(n) foldMap which is strict in accumulator. It uses same implementation as corresponding method of Foldable type class. Note it's implemented in terms of foldl' so it fuses in most contexts.

Since: 0.12.2.0

Specialised folds

all :: (a -> Bool) -> Vector a -> Bool

O(n) Check if all elements satisfy the predicate.

Examples

>>> import qualified Data.Vector as V
>>> V.all even $ V.fromList [2, 4, 12 :: Int]
True
>>> V.all even $ V.fromList [2, 4, 13 :: Int]
False
>>> V.all even (V.empty :: V.Vector Int)
True

any :: (a -> Bool) -> Vector a -> Bool

O(n) Check if any element satisfies the predicate.

Examples

>>> import qualified Data.Vector as V
>>> V.any even $ V.fromList [1, 3, 7 :: Int]
False
>>> V.any even $ V.fromList [3, 2, 13 :: Int]
True
>>> V.any even (V.empty :: V.Vector Int)
False

and :: Vector Bool -> Bool

O(n) Check if all elements are True

Examples

>>> import qualified Data.Vector as V
>>> V.and $ V.fromList [True, False]
False
>>> V.and V.empty
True

or :: Vector Bool -> Bool

O(n) Check if any element is True

Examples

>>> import qualified Data.Vector as V
>>> V.or $ V.fromList [True, False]
True
>>> V.or V.empty
False

sum :: Num a => Vector a -> a

O(n) Compute the sum of the elements

Examples

>>> import qualified Data.Vector as V
>>> V.sum $ V.fromList [300,20,1 :: Int]
321
>>> V.sum (V.empty :: V.Vector Int)
0

product :: Num a => Vector a -> a

O(n) Compute the produce of the elements

Examples

>>> import qualified Data.Vector as V
>>> V.product $ V.fromList [1,2,3,4 :: Int]
24
>>> V.product (V.empty :: V.Vector Int)
1

maximum :: Ord a => Vector a -> a

O(n) Yield the maximum element of the vector. The vector may not be empty.

Examples

>>> import qualified Data.Vector as V
>>> V.maximum $ V.fromList [2.0, 1.0]
2.0

maximumBy :: (a -> a -> Ordering) -> Vector a -> a

O(n) Yield the maximum element of the vector according to the given comparison function. The vector may not be empty.

minimum :: Ord a => Vector a -> a

O(n) Yield the minimum element of the vector. The vector may not be empty.

Examples

>>> import qualified Data.Vector as V
>>> V.minimum $ V.fromList [2.0, 1.0]
1.0

minimumBy :: (a -> a -> Ordering) -> Vector a -> a

O(n) Yield the minimum element of the vector according to the given comparison function. The vector may not be empty.

minIndex :: Ord a => Vector a -> Int

O(n) Yield the index of the minimum element of the vector. The vector may not be empty.

minIndexBy :: (a -> a -> Ordering) -> Vector a -> Int

O(n) Yield the index of the minimum element of the vector according to the given comparison function. The vector may not be empty.

maxIndex :: Ord a => Vector a -> Int

O(n) Yield the index of the maximum element of the vector. The vector may not be empty.

maxIndexBy :: (a -> a -> Ordering) -> Vector a -> Int

O(n) Yield the index of the maximum element of the vector according to the given comparison function. The vector may not be empty.

Monadic folds

foldM :: Monad m => (a -> b -> m a) -> a -> Vector b -> m a

O(n) Monadic fold

ifoldM :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m a

O(n) Monadic fold (action applied to each element and its index)

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

O(n) Monadic fold with strict accumulator

ifoldM' :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m a

O(n) Monadic fold with strict accumulator (action applied to each element and its index)

fold1M :: Monad m => (a -> a -> m a) -> Vector a -> m a

O(n) Monadic fold over non-empty vectors

fold1M' :: Monad m => (a -> a -> m a) -> Vector a -> m a

O(n) Monadic fold over non-empty vectors with strict accumulator

foldM_ :: Monad m => (a -> b -> m a) -> a -> Vector b -> m ()

O(n) Monadic fold that discards the result

ifoldM_ :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m ()

O(n) Monadic fold that discards the result (action applied to each element and its index)

foldM'_ :: Monad m => (a -> b -> m a) -> a -> Vector b -> m ()

O(n) Monadic fold with strict accumulator that discards the result

ifoldM'_ :: Monad m => (a -> Int -> b -> m a) -> a -> Vector b -> m ()

O(n) Monadic fold with strict accumulator that discards the result (action applied to each element and its index)

fold1M_ :: Monad m => (a -> a -> m a) -> Vector a -> m ()

O(n) Monadic fold over non-empty vectors that discards the result

fold1M'_ :: Monad m => (a -> a -> m a) -> Vector a -> m ()

O(n) Monadic fold over non-empty vectors with strict accumulator that discards the result

Monadic sequencing

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

Evaluate each action and collect the results

sequence_ :: Monad m => Vector (m a) -> m ()

Evaluate each action and discard the results

Prefix sums (scans)

prescanl :: (a -> b -> a) -> a -> Vector b -> Vector a

O(n) Prescan

prescanl f z = init . scanl f z

Example: prescanl (+) 0 <1,2,3,4> = <0,1,3,6>

prescanl' :: (a -> b -> a) -> a -> Vector b -> Vector a

O(n) Prescan with strict accumulator

postscanl :: (a -> b -> a) -> a -> Vector b -> Vector a

O(n) Scan

postscanl f z = tail . scanl f z

Example: postscanl (+) 0 <1,2,3,4> = <1,3,6,10>

postscanl' :: (a -> b -> a) -> a -> Vector b -> Vector a

O(n) Scan with strict accumulator

scanl :: (a -> b -> a) -> a -> Vector b -> Vector a

O(n) Haskell-style scan

scanl f z <x1,...,xn> = <y1,...,y(n+1)>
  where y1 = z
        yi = f y(i-1) x(i-1)

Example: scanl (+) 0 <1,2,3,4> = <0,1,3,6,10>

scanl' :: (a -> b -> a) -> a -> Vector b -> Vector a

O(n) Haskell-style scan with strict accumulator

scanl1 :: (a -> a -> a) -> Vector a -> Vector a

O(n) Scan over a non-empty vector

scanl f <x1,...,xn> = <y1,...,yn>
  where y1 = x1
        yi = f y(i-1) xi

scanl1' :: (a -> a -> a) -> Vector a -> Vector a

O(n) Scan over a non-empty vector with a strict accumulator

iscanl :: (Int -> a -> b -> a) -> a -> Vector b -> Vector a

O(n) Scan over a vector with its index

Since: 0.12.0.0

iscanl' :: (Int -> a -> b -> a) -> a -> Vector b -> Vector a

O(n) Scan over a vector (strictly) with its index

Since: 0.12.0.0

prescanr :: (a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left prescan

prescanr f z = reverse . prescanl (flip f) z . reverse

prescanr' :: (a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left prescan with strict accumulator

postscanr :: (a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left scan

postscanr' :: (a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left scan with strict accumulator

scanr :: (a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left Haskell-style scan

scanr' :: (a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left Haskell-style scan with strict accumulator

scanr1 :: (a -> a -> a) -> Vector a -> Vector a

O(n) Right-to-left scan over a non-empty vector

scanr1' :: (a -> a -> a) -> Vector a -> Vector a

O(n) Right-to-left scan over a non-empty vector with a strict accumulator

iscanr :: (Int -> a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left scan over a vector with its index

Since: 0.12.0.0

iscanr' :: (Int -> a -> b -> b) -> b -> Vector a -> Vector b

O(n) Right-to-left scan over a vector (strictly) with its index

Since: 0.12.0.0

Comparisons

eqBy :: (a -> b -> Bool) -> Vector a -> Vector b -> Bool

O(n) Check if two vectors are equal using supplied equality predicate.

Since: 0.12.2.0

cmpBy :: (a -> b -> Ordering) -> Vector a -> Vector b -> Ordering

O(n) Compare two vectors using supplied comparison function for vector elements. Comparison works same as for lists.

cmpBy compare == compare

Since: 0.12.2.0

Conversions

Lists

toList :: Vector a -> [a]

O(n) Convert a vector to a list

fromList :: [a] -> Vector a

O(n) Convert a list to a vector

fromListN :: Int -> [a] -> Vector a

O(n) Convert the first n elements of a list to a vector

fromListN n xs = fromList (take n xs)

Arrays

fromArray :: Array a -> Vector a

O(1) Convert an array to a vector.

Since: 0.12.2.0

toArray :: Vector a -> Array a

O(n) Convert a vector to an array.

Since: 0.12.2.0

Other vector types

convert :: (Vector v a, Vector w a) => v a -> w a

O(n) Convert different vector types

Mutable vectors

freeze :: PrimMonad m => MVector (PrimState m) a -> m (Vector a)

O(n) Yield an immutable copy of the mutable vector.

thaw :: PrimMonad m => Vector a -> m (MVector (PrimState m) a)

O(n) Yield a mutable copy of the immutable vector.

copy :: PrimMonad m => MVector (PrimState m) a -> Vector a -> m ()

O(n) Copy an immutable vector into a mutable one. The two vectors must have the same length.

unsafeFreeze :: PrimMonad m => MVector (PrimState m) a -> m (Vector a)

O(1) Unsafe convert a mutable vector to an immutable one without copying. The mutable vector may not be used after this operation.

unsafeThaw :: PrimMonad m => Vector a -> m (MVector (PrimState m) a)

O(1) Unsafely convert an immutable vector to a mutable one without copying. Note that this is very dangerous function and generally it's only safe to read from resulting vector. In which case immutable vector could be used safely as well.

Problem with mutation happens because GHC has a lot of freedom to introduce sharing. As a result mutable vectors produced by unsafeThaw may or may not share same underlying buffer. For example:

foo = do
  let vec = V.generate 10 id
  mvec <- V.unsafeThaw vec
  do_something mvec

Here GHC could lift vec outside of foo which means all calls to do_something will use same buffer with possibly disastrous results. Whether such aliasing happens or not depends on program in question, optimization levels, and GHC flags.

All in all attempts to modify vector after unsafeThaw falls out of domain of software engineering and into realm of black magic, dark rituals, and unspeakable horrors. Only advice that could be given is: "don't attempt to mutate vector after unsafeThaw unless you know how to prevent GHC from aliasing buffers accidentally. We don't"

unsafeCopy :: PrimMonad m => MVector (PrimState m) a -> Vector a -> m ()

O(n) Copy an immutable vector into a mutable one. The two vectors must have the same length. This is not checked.