vector-0.10.0.1: Efficient Arrays

Portability non-portable experimental Roman Leshchinskiy <[email protected]> None

Data.Vector

Description

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

Synopsis

# Boxed vectors

data Vector a Source

Boxed vectors, supporting efficient slicing.

Instances

 Monad Vector Functor Vector Typeable1 Vector MonadPlus Vector Applicative Vector Foldable Vector Traversable Vector Alternative Vector Vector Vector a Eq a => Eq (Vector a) Data a => Data (Vector a) Ord a => Ord (Vector a) Read a => Read (Vector a) Show a => Show (Vector a) NFData a => NFData (Vector a) Monoid (Vector a)

data MVector s a Source

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

Instances

 Typeable2 MVector MVector MVector a

# Accessors

## Length information

length :: Vector a -> IntSource

O(1) Yield the length of the vector.

null :: Vector a -> BoolSource

O(1) Test whether a vector if empty

## Indexing

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

O(1) Indexing

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

O(1) Safe indexing

head :: Vector a -> aSource

O(1) First element

last :: Vector a -> aSource

O(1) Last element

unsafeIndex :: Vector a -> Int -> aSource

O(1) Unsafe indexing without bounds checking

unsafeHead :: Vector a -> aSource

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

unsafeLast :: Vector a -> aSource

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

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

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.

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 aSource

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 aSource

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

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 aSource

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)

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 aSource

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

tail :: Vector a -> Vector aSource

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

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

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 aSource

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)Source

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.

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 aSource

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 aSource

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 aSource

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 aSource

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

O(1) Empty vector

singleton :: a -> Vector aSource

O(1) Vector with exactly one element

replicate :: Int -> a -> Vector aSource

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

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

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

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

O(n) Apply function n times to value. Zeroth element is original value.

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

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)Source

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

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

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`>
```

## Unfolding

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

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 aSource

O(n) Construct a vector with at most `n` by repeatedly applying the generator function to the 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>
```

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

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 f <a,b,c>
```

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

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 f <c,b,a>
```

## Enumeration

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

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 aSource

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 aSource

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 aSource

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 aSource

O(n) Prepend an element

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

O(n) Append an element

(++) :: Vector a -> Vector a -> Vector aSource

O(m+n) Concatenate two vectors

concat :: [Vector a] -> Vector aSource

O(n) Concatenate all vectors in the list

## Restricting memory usage

force :: Vector a -> Vector aSource

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

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>
```

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>
```

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 aSource

Same as (`//`) but without bounds checking.

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

Same as `update` but without bounds checking.

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

Same as `update_` but without bounds checking.

## Accumulations

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`.

``` accum (+) <5,9,2> [(2,4),(1,6),(0,3),(1,7)] = <5+3, 9+6+7, 2+4>
```

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`.

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

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 aSource

Same as `accum` but without bounds checking.

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

Same as `accumulate` but without bounds checking.

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

Same as `accumulate_` but without bounds checking.

## Permutations

reverse :: Vector a -> Vector aSource

O(n) Reverse a vector

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

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 aSource

Same as `backpermute` but without bounds checking.

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

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)Source

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

## Mapping

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

O(n) Map a function over a vector

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

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

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

Map a function over a vector and concatenate the results.

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

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

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

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

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

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

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

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

## Zipping

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

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

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

Zip three vectors with the given function.

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

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

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

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

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 dSource

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 eSource

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

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

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

Elementwise pairing of array elements.

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

zip together three vectors into a vector of triples

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

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

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

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

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

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

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

## Unzipping

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

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

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

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

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

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

# Working with predicates

## Filtering

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

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

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

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)Source

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

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

O(n) Yield the longest prefix of elements satisfying the predicate without copying.

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

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

## Partitioning

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

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)Source

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`.

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

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)Source

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 -> BoolSource

O(n) Check if the vector contains an element

notElem :: Eq a => a -> Vector a -> BoolSource

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

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

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

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

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 IntSource

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

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

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 IntSource

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 -> aSource

O(n) Left fold

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

O(n) Left fold on non-empty vectors

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

O(n) Left fold with strict accumulator

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

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

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

O(n) Right fold

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

O(n) Right fold on non-empty vectors

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

O(n) Right fold with a strict accumulator

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

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

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

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

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

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

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

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

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

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

## Specialised folds

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

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

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

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

and :: Vector Bool -> BoolSource

O(n) Check if all elements are `True`

or :: Vector Bool -> BoolSource

O(n) Check if any element is `True`

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

O(n) Compute the sum of the elements

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

O(n) Compute the produce of the elements

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

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

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

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 -> aSource

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

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

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 -> IntSource

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

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

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 -> IntSource

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

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

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

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

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

O(n) Monadic fold with strict accumulator

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

O(n) Monadic fold over non-empty vectors

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

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

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

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

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

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

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

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

Evaluate each action and collect the results

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

Evaluate each action and discard the results

# Prefix sums (scans)

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

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 aSource

O(n) Prescan with strict accumulator

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

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 aSource

O(n) Scan with strict accumulator

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

``` 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 aSource

O(n) Haskell-style scan with strict accumulator

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

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 aSource

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

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

O(n) Right-to-left prescan

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

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

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

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

O(n) Right-to-left scan

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

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

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

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

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

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

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

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

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

# Conversions

## Lists

toList :: Vector a -> [a]Source

O(n) Convert a vector to a list

fromList :: [a] -> Vector aSource

O(n) Convert a list to a vector

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

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

``` fromListN n xs = `fromList` (`take` n xs)
```

## Other vector types

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

O(n) Convert different vector types

## Mutable vectors

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

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

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

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

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

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)Source

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)Source

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

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

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