vector-0.9.1: Efficient Arrays

Portabilitynon-portable
Stabilityexperimental
MaintainerRoman Leshchinskiy <rl@cse.unsw.edu.au>
Safe HaskellTrustworthy

Data.Vector.Generic.Safe

Contents

Description

Safe interface to Data.Vector.Generic

Synopsis

Immutable vectors

class MVector (Mutable v) a => Vector v a Source

Class of immutable vectors. Every immutable vector is associated with its mutable version through the Mutable type family. Methods of this class should not be used directly. Instead, Data.Vector.Generic and other Data.Vector modules provide safe and fusible wrappers.

Minimum complete implementation:

type family Mutable v :: * -> * -> *Source

Mutable v s a is the mutable version of the pure vector type v a with the state token s

Accessors

Length information

length :: Vector v a => v a -> IntSource

O(1) Yield the length of the vector.

null :: Vector v a => v a -> BoolSource

O(1) Test whether a vector if empty

Indexing

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

O(1) Indexing

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

O(1) Safe indexing

head :: Vector v a => v a -> aSource

O(1) First element

last :: Vector v a => v a -> aSource

O(1) Last element

Monadic indexing

indexM :: (Vector v a, Monad m) => v a -> Int -> m aSource

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 :: (Vector v a, Monad m) => v a -> m aSource

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

lastM :: (Vector v a, Monad m) => v a -> m aSource

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

Extracting subvectors (slicing)

sliceSource

Arguments

:: Vector v a 
=> Int

i starting index

-> Int

n length

-> v a 
-> v a 

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

init :: Vector v a => v a -> v aSource

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

tail :: Vector v a => v a -> v aSource

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

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

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

drop :: Vector v a => Int -> v a -> v 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 :: Vector v a => Int -> v a -> (v a, v 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.

Construction

Initialisation

empty :: Vector v a => v aSource

O(1) Empty vector

singleton :: forall v a. Vector v a => a -> v aSource

O(1) Vector with exactly one element

replicate :: forall v a. Vector v a => Int -> a -> v aSource

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

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

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

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

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

Monadic initialisation

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

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

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

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

create :: Vector v a => (forall s. ST s (Mutable v s a)) -> v aSource

Execute the monadic action and freeze the resulting vector.

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

Unfolding

unfoldr :: Vector v a => (b -> Maybe (a, b)) -> b -> v 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 :: Vector v a => Int -> (b -> Maybe (a, b)) -> b -> v 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>

Enumeration

enumFromN :: (Vector v a, Num a) => a -> Int -> v 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 :: forall v a. (Vector v a, Num a) => a -> a -> Int -> v 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 :: (Vector v a, Enum a) => a -> a -> v aSource

O(n) Enumerate values from x to y.

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

enumFromThenTo :: (Vector v a, Enum a) => a -> a -> a -> v 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 :: forall v a. Vector v a => a -> v a -> v aSource

O(n) Prepend an element

snoc :: forall v a. Vector v a => v a -> a -> v aSource

O(n) Append an element

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

O(m+n) Concatenate two vectors

concat :: Vector v a => [v a] -> v aSource

O(n) Concatenate all vectors in the list

Restricting memory usage

force :: Vector v a => v a -> v 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

Bulk updates

(//)Source

Arguments

:: Vector v a 
=> v a

initial vector (of length m)

-> [(Int, a)]

list of index/value pairs (of length n)

-> v 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>

updateSource

Arguments

:: (Vector v a, Vector v (Int, a)) 
=> v a

initial vector (of length m)

-> v (Int, a)

vector of index/value pairs (of length n)

-> v 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_Source

Arguments

:: (Vector v a, Vector v Int) 
=> v a

initial vector (of length m)

-> v Int

index vector (of length n1)

-> v a

value vector (of length n2)

-> v 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>

This function is useful for instances of Vector that cannot store pairs. Otherwise, update is probably more convenient.

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

Accumulations

accumSource

Arguments

:: Vector v a 
=> (a -> b -> a)

accumulating function f

-> v a

initial vector (of length m)

-> [(Int, b)]

list of index/value pairs (of length n)

-> v 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>

accumulateSource

Arguments

:: (Vector v a, Vector v (Int, b)) 
=> (a -> b -> a)

accumulating function f

-> v a

initial vector (of length m)

-> v (Int, b)

vector of index/value pairs (of length n)

-> v 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>

accumulate_Source

Arguments

:: (Vector v a, Vector v Int, Vector v b) 
=> (a -> b -> a)

accumulating function f

-> v a

initial vector (of length m)

-> v Int

index vector (of length n1)

-> v b

value vector (of length n2)

-> v 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>

This function is useful for instances of Vector that cannot store pairs. Otherwise, accumulate is probably more convenient:

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

Permutations

reverse :: Vector v a => v a -> v aSource

O(n) Reverse a vector

backpermuteSource

Arguments

:: (Vector v a, Vector v Int) 
=> v a

xs value vector

-> v Int

is index vector (of length n)

-> v 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>

Safe destructive updates

modify :: Vector v a => (forall s. Mutable v s a -> ST s ()) -> v a -> v 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 v a, Vector v (Int, a)) => v a -> v (Int, a)Source

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

Mapping

map :: (Vector v a, Vector v b) => (a -> b) -> v a -> v bSource

O(n) Map a function over a vector

imap :: (Vector v a, Vector v b) => (Int -> a -> b) -> v a -> v bSource

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

concatMap :: (Vector v a, Vector v b) => (a -> v b) -> v a -> v bSource

Map a function over a vector and concatenate the results.

Monadic mapping

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

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

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

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

forM :: (Monad m, Vector v a, Vector v b) => v a -> (a -> m b) -> m (v 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 v a) => v 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 :: (Vector v a, Vector v b, Vector v c) => (a -> b -> c) -> v a -> v b -> v cSource

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

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

Zip three vectors with the given function.

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

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

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

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

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

izipWith3 :: (Vector v a, Vector v b, Vector v c, Vector v d) => (Int -> a -> b -> c -> d) -> v a -> v b -> v c -> v dSource

izipWith4 :: (Vector v a, Vector v b, Vector v c, Vector v d, Vector v e) => (Int -> a -> b -> c -> d -> e) -> v a -> v b -> v c -> v d -> v eSource

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

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

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

O(min(m,n)) Zip two vectors

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

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

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

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

Monadic zipping

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

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

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

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

Unzipping

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

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

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

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

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

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

Working with predicates

Filtering

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

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

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

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

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

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

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

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

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

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

Partitioning

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

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

break :: Vector v a => (a -> Bool) -> v a -> (v a, v 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 :: (Vector v a, Eq a) => a -> v a -> BoolSource

O(n) Check if the vector contains an element

notElem :: (Vector v a, Eq a) => a -> v a -> BoolSource

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

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

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

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

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

findIndices :: (Vector v a, Vector v Int) => (a -> Bool) -> v a -> v IntSource

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

elemIndex :: (Vector v a, Eq a) => a -> v 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 :: (Vector v a, Vector v Int, Eq a) => a -> v a -> v 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 :: Vector v b => (a -> b -> a) -> a -> v b -> aSource

O(n) Left fold

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

O(n) Left fold on non-empty vectors

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

O(n) Left fold with strict accumulator

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

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

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

O(n) Right fold

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

O(n) Right fold on non-empty vectors

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

O(n) Right fold with a strict accumulator

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

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

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

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

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

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

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

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

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

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

Specialised folds

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

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

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

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

and :: Vector v Bool => v Bool -> BoolSource

O(n) Check if all elements are True

or :: Vector v Bool => v Bool -> BoolSource

O(n) Check if any element is True

sum :: (Vector v a, Num a) => v a -> aSource

O(n) Compute the sum of the elements

product :: (Vector v a, Num a) => v a -> aSource

O(n) Compute the produce of the elements

maximum :: (Vector v a, Ord a) => v a -> aSource

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

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

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

minimum :: (Vector v a, Ord a) => v a -> aSource

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

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

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

minIndex :: (Vector v a, Ord a) => v a -> IntSource

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

minIndexBy :: Vector v a => (a -> a -> Ordering) -> v 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 :: (Vector v a, Ord a) => v a -> IntSource

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

maxIndexBy :: Vector v a => (a -> a -> Ordering) -> v 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.

Monadic folds

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

O(n) Monadic fold

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

O(n) Monadic fold with strict accumulator

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

O(n) Monadic fold over non-empty vectors

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

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

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

O(n) Monadic fold that discards the result

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

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

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

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

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

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

Monadic sequencing

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

Evaluate each action and collect the results

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

Evaluate each action and discard the results

Prefix sums (scans)

prescanl :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v aSource

O(n) Prescan

 prescanl f z = init . scanl f z

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

prescanl' :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v aSource

O(n) Prescan with strict accumulator

postscanl :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v aSource

O(n) Scan

 postscanl f z = tail . scanl f z

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

postscanl' :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v aSource

O(n) Scan with strict accumulator

scanl :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v aSource

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' :: (Vector v a, Vector v b) => (a -> b -> a) -> a -> v b -> v aSource

O(n) Haskell-style scan with strict accumulator

scanl1 :: Vector v a => (a -> a -> a) -> v a -> v 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' :: Vector v a => (a -> a -> a) -> v a -> v aSource

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

prescanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v bSource

O(n) Right-to-left prescan

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

prescanr' :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v bSource

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

postscanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v bSource

O(n) Right-to-left scan

postscanr' :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v bSource

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

scanr :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v bSource

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

scanr' :: (Vector v a, Vector v b) => (a -> b -> b) -> b -> v a -> v bSource

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

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

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

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

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

Conversions

Lists

toList :: Vector v a => v a -> [a]Source

O(n) Convert a vector to a list

fromList :: Vector v a => [a] -> v aSource

O(n) Convert a list to a vector

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

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

 fromListN n xs = fromList (take n xs)

Different vector types

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

O(n) Convert different vector types

Mutable vectors

freeze :: (PrimMonad m, Vector v a) => Mutable v (PrimState m) a -> m (v a)Source

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

thaw :: (PrimMonad m, Vector v a) => v a -> m (Mutable v (PrimState m) a)Source

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

copy :: (PrimMonad m, Vector v a) => Mutable v (PrimState m) a -> v a -> m ()Source

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

Fusion support

Conversion to/from Streams

stream :: Vector v a => v a -> Stream aSource

O(1) Convert a vector to a Stream

unstream :: Vector v a => Stream a -> v aSource

O(n) Construct a vector from a Stream

streamR :: Vector v a => v a -> Stream aSource

O(1) Convert a vector to a Stream, proceeding from right to left

unstreamR :: Vector v a => Stream a -> v aSource

O(n) Construct a vector from a Stream, proceeding from right to left

Recycling support

new :: Vector v a => New v a -> v aSource

Construct a vector from a monadic initialiser.

clone :: Vector v a => v a -> New v aSource

Convert a vector to an initialiser which, when run, produces a copy of the vector.

Utilities

Comparisons

eq :: (Vector v a, Eq a) => v a -> v a -> BoolSource

O(n) Check if two vectors are equal. All Vector instances are also instances of Eq and it is usually more appropriate to use those. This function is primarily intended for implementing Eq instances for new vector types.

cmp :: (Vector v a, Ord a) => v a -> v a -> OrderingSource

O(n) Compare two vectors lexicographically. All Vector instances are also instances of Ord and it is usually more appropriate to use those. This function is primarily intended for implementing Ord instances for new vector types.

Data and Typeable

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

Generic definion of gfoldl that views a Vector as a list.

dataCast :: (Vector v a, Data a, Typeable1 v, Typeable1 t) => (forall d. Data d => c (t d)) -> Maybe (c (v a))Source