Data.Vector.Mutable

Mutable boxed vectors.

Mutable boxed vectors

data MVector s a

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

Constructors

MVector

Fields

• !Int

  Offset in underlying array

• !Int

  Size of slice

• !(MutableArray s a)

  Underlying array

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)

type IOVector = MVector RealWorld

type STVector s = MVector s

Accessors

Length information

length :: MVector s a -> Int

Length of the mutable vector.

null :: MVector s a -> Bool

Check whether the vector is empty

Extracting subvectors

slice

Arguments

:: Int

i starting index

-> Int

n length

-> MVector s a

-> MVector s a

Yield a part of the mutable vector without copying it. The vector must contain at least i+n elements.

init :: MVector s a -> MVector s a

tail :: MVector s a -> MVector s a

take :: Int -> MVector s a -> MVector s a

drop :: Int -> MVector s a -> MVector s a

splitAt :: Int -> MVector s a -> (MVector s a, MVector s a)

unsafeSlice

Arguments

:: Int

starting index

-> Int

length of the slice

-> MVector s a

-> MVector s a

Yield a part of the mutable vector without copying it. No bounds checks are performed.

unsafeInit :: MVector s a -> MVector s a

unsafeTail :: MVector s a -> MVector s a

unsafeTake :: Int -> MVector s a -> MVector s a

unsafeDrop :: Int -> MVector s a -> MVector s a

Overlapping

overlaps :: MVector s a -> MVector s a -> Bool

Check whether two vectors overlap.

Construction

Initialisation

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

Create a mutable vector of the given length.

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

Create a mutable vector of the given length. The vector elements are set to bottom so accessing them will cause an exception.

Since: 0.5

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

Create a mutable vector of the given length (0 if the length is negative) and fill it with an initial value.

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

Create a mutable vector of the given length (0 if the length is negative) and fill it with values produced by repeatedly executing the monadic action.

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

Create a copy of a mutable vector.

Growing

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

Grow a boxed vector by the given number of elements. The number must be non-negative. Same semantics as in grow for generic vector. It differs from grow functions for unpacked vectors, however, in that only pointers to values are copied over, therefore values themselves will be shared between two vectors. This is an important distinction to know about during memory usage analysis and in case when values themselves are of a mutable type, eg. IORef or another mutable vector.

Examples

>>> import qualified Data.Vector as V
>>> import qualified Data.Vector.Mutable as MV
>>> mv <- V.thaw $ V.fromList ([10, 20, 30] :: [Integer])
>>> mv' <- MV.grow mv 2

The two extra elements at the end of the newly allocated vector will be uninitialized and will result in an error if evaluated, so me must overwrite them with new values first:

>>> MV.write mv' 3 999
>>> MV.write mv' 4 777
>>> V.unsafeFreeze mv'
[10,20,30,999,777]

It is important to note that the source mutable vector is not affected when the newly allocated one is mutated.

>>> MV.write mv' 2 888
>>> V.unsafeFreeze mv'
[10,20,888,999,777]
>>> V.unsafeFreeze mv
[10,20,30]

Since: 0.5

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

Grow a vector by the given number of elements. The number must be non-negative but this is not checked. Same semantics as in unsafeGrow for generic vector.

Since: 0.5

Restricting memory usage

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

Reset all elements of the vector to some undefined value, clearing all references to external objects. This is usually a noop for unboxed vectors.

Accessing individual elements

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

Yield the element at the given position.

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

Replace the element at the given position.

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

Modify the element at the given position.

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

Swap the elements at the given positions.

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

Yield the element at the given position. No bounds checks are performed.

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

Replace the element at the given position. No bounds checks are performed.

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

Modify the element at the given position. No bounds checks are performed.

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

Swap the elements at the given positions. No bounds checks are performed.

Modifying vectors

nextPermutation :: (PrimMonad m, Ord e) => MVector (PrimState m) e -> m Bool

Compute the next (lexicographically) permutation of given vector in-place. Returns False when input is the last permutation

Filling and copying

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

Set all elements of the vector to the given value.

copy

Arguments

:: PrimMonad m

=> MVector (PrimState m) a

target

-> MVector (PrimState m) a

source

-> m ()

Copy a vector. The two vectors must have the same length and may not overlap.

move

Arguments

:: PrimMonad m

=> MVector (PrimState m) a

target

-> MVector (PrimState m) a

source

-> m ()

Move the contents of a vector. The two vectors must have the same length.

If the vectors do not overlap, then this is equivalent to copy. Otherwise, the copying is performed as if the source vector were copied to a temporary vector and then the temporary vector was copied to the target vector.

unsafeCopy

Arguments

:: PrimMonad m

=> MVector (PrimState m) a

target

-> MVector (PrimState m) a

source

-> m ()

Copy a vector. The two vectors must have the same length and may not overlap. This is not checked.

unsafeMove

Arguments

:: PrimMonad m

=> MVector (PrimState m) a

target

-> MVector (PrimState m) a

source

-> m ()

Move the contents of a vector. The two vectors must have the same length, but this is not checked.

If the vectors do not overlap, then this is equivalent to unsafeCopy. Otherwise, the copying is performed as if the source vector were copied to a temporary vector and then the temporary vector was copied to the target vector.

Arrays

fromMutableArray :: PrimMonad m => MutableArray (PrimState m) a -> m (MVector (PrimState m) a)

O(n) Make a copy of a mutable array to a new mutable vector.

Since: 0.12.2.0

toMutableArray :: PrimMonad m => MVector (PrimState m) a -> m (MutableArray (PrimState m) a)

O(n) Make a copy of a mutable vector into a new mutable array.

Since: 0.12.2.0