Data.Primitive.Unlifted.Array

GHC contains three general classes of value types:

1. Unboxed types: values are machine values made up of fixed numbers of bytes
2. Unlifted types: values are pointers, but strictly evaluated
3. Lifted types: values are pointers, lazily evaluated

The first category can be stored in a ByteArray, and this allows types in category 3 that are simple wrappers around category 1 types to be stored more efficiently using a ByteArray. This module provides the same facility for category 2 types.

GHC has two primitive types, ArrayArray# and MutableArrayArray#. These are arrays of pointers, but of category 2 values, so they are known to not be bottom. This allows types that are wrappers around such types to be stored in an array without an extra level of indirection.

The way that the ArrayArray# API works is that one can read and write ArrayArray# values to the positions. This works because all category 2 types share a uniform representation, unlike unboxed values which are represented by varying (by type) numbers of bytes. However, using the this makes the internal API very unsafe to use, as one has to coerce values to and from ArrayArray#.

The API presented by this module is more type safe. UnliftedArray and MutableUnliftedArray are parameterized by the type of arrays they contain, and the coercions necessary are abstracted into a class, PrimUnlifted, of things that are eligible to be stored.

Types

data UnliftedArray a

Constructors

UnliftedArray ArrayArray#

Instances

PrimUnlifted a => IsList (UnliftedArray a)

Defined in Data.Primitive.Unlifted.Array

Associated Types

type Item (UnliftedArray a) :: Type

Methods

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

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

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

(Eq a, PrimUnlifted a) => Eq (UnliftedArray a)

Defined in Data.Primitive.Unlifted.Array

Methods

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

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

(Show a, PrimUnlifted a) => Show (UnliftedArray a)

Defined in Data.Primitive.Unlifted.Array

Methods

showsPrec :: Int -> UnliftedArray a -> ShowS

show :: UnliftedArray a -> String

showList :: [UnliftedArray a] -> ShowS

PrimUnlifted a => Semigroup (UnliftedArray a)

Defined in Data.Primitive.Unlifted.Array

Methods

(<>) :: UnliftedArray a -> UnliftedArray a -> UnliftedArray a

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

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

PrimUnlifted a => Monoid (UnliftedArray a)

Defined in Data.Primitive.Unlifted.Array

Methods

mempty :: UnliftedArray a

mappend :: UnliftedArray a -> UnliftedArray a -> UnliftedArray a

mconcat :: [UnliftedArray a] -> UnliftedArray a

type Item (UnliftedArray a)

Defined in Data.Primitive.Unlifted.Array

type Item (UnliftedArray a) = a

data MutableUnliftedArray s a

Constructors

MutableUnliftedArray (MutableArrayArray# s)

Instances

Eq (MutableUnliftedArray s a)

Defined in Data.Primitive.Unlifted.Array

Methods

(==) :: MutableUnliftedArray s a -> MutableUnliftedArray s a -> Bool

(/=) :: MutableUnliftedArray s a -> MutableUnliftedArray s a -> Bool

Operations

newUnliftedArray

Arguments

:: (PrimMonad m, PrimUnlifted a)

=> Int

size

-> a

initial value

-> m (MutableUnliftedArray (PrimState m) a)

Creates a new MutableUnliftedArray with the specified value as initial contents. This is slower than unsafeNewUnliftedArray, but safer.

unsafeNewUnliftedArray

Arguments

:: PrimMonad m

=> Int

size

-> m (MutableUnliftedArray (PrimState m) a)

Creates a new MutableUnliftedArray. This function is unsafe because it initializes all elements of the array as pointers to the array itself. Attempting to read one of these elements before writing to it is in effect an unsafe coercion from the MutableUnliftedArray s a to the element type.

sizeofUnliftedArray :: UnliftedArray e -> Int

Yields the length of an UnliftedArray.

sizeofMutableUnliftedArray :: MutableUnliftedArray s e -> Int

Yields the length of a MutableUnliftedArray.

sameMutableUnliftedArray :: MutableUnliftedArray s a -> MutableUnliftedArray s a -> Bool

Determines whether two MutableUnliftedArray values are the same. This is object/pointer identity, not based on the contents.

writeUnliftedArray :: (PrimMonad m, PrimUnlifted a) => MutableUnliftedArray (PrimState m) a -> Int -> a -> m ()

readUnliftedArray :: (PrimMonad m, PrimUnlifted a) => MutableUnliftedArray (PrimState m) a -> Int -> m a

indexUnliftedArray :: PrimUnlifted a => UnliftedArray a -> Int -> a

unsafeFreezeUnliftedArray :: PrimMonad m => MutableUnliftedArray (PrimState m) a -> m (UnliftedArray a)

Freezes a MutableUnliftedArray, yielding an UnliftedArray. This simply marks the array as frozen in place, so it should only be used when no further modifications to the mutable array will be performed.

freezeUnliftedArray

Arguments

:: PrimMonad m

=> MutableUnliftedArray (PrimState m) a

source

-> Int

offset

-> Int

length

-> m (UnliftedArray a)

Freezes a portion of a MutableUnliftedArray, yielding an UnliftedArray. This operation is safe, in that it copies the frozen portion, and the existing mutable array may still be used afterward.

thawUnliftedArray

Arguments

:: PrimMonad m

=> UnliftedArray a

source

-> Int

offset

-> Int

length

-> m (MutableUnliftedArray (PrimState m) a)

Thaws a portion of an UnliftedArray, yielding a MutableUnliftedArray. This copies the thawed portion, so mutations will not affect the original array.

setUnliftedArray

Arguments

:: (PrimMonad m, PrimUnlifted a)

=> MutableUnliftedArray (PrimState m) a

destination

-> a

value to fill with

-> Int

offset

-> Int

length

-> m ()

copyUnliftedArray

Arguments

:: PrimMonad m

=> MutableUnliftedArray (PrimState m) a

destination

-> Int

offset into destination

-> UnliftedArray a

source

-> Int

offset into source

-> Int

number of elements to copy

-> m ()

Copies the contents of an immutable array into a mutable array.

copyMutableUnliftedArray

Arguments

:: PrimMonad m

=> MutableUnliftedArray (PrimState m) a

destination

-> Int

offset into destination

-> MutableUnliftedArray (PrimState m) a

source

-> Int

offset into source

-> Int

number of elements to copy

-> m ()

Copies the contents of one mutable array into another.

cloneUnliftedArray

Arguments

:: UnliftedArray a

source

-> Int

offset

-> Int

length

-> UnliftedArray a

Creates a copy of a portion of an UnliftedArray

cloneMutableUnliftedArray

Arguments

:: PrimMonad m

=> MutableUnliftedArray (PrimState m) a

source

-> Int

offset

-> Int

length

-> m (MutableUnliftedArray (PrimState m) a)

Creates a new MutableUnliftedArray containing a copy of a portion of another mutable array.

emptyUnliftedArray :: UnliftedArray a

singletonUnliftedArray :: PrimUnlifted a => a -> UnliftedArray a

runUnliftedArray :: (forall s. ST s (MutableUnliftedArray s a)) -> UnliftedArray a

Execute a stateful computation and freeze the resulting array.

List Conversion

unliftedArrayToList :: PrimUnlifted a => UnliftedArray a -> [a]

Convert the unlifted array to a list.

unliftedArrayFromList :: PrimUnlifted a => [a] -> UnliftedArray a

unliftedArrayFromListN :: forall a. PrimUnlifted a => Int -> [a] -> UnliftedArray a

Folding

foldrUnliftedArray :: forall a b. PrimUnlifted a => (a -> b -> b) -> b -> UnliftedArray a -> b

foldrUnliftedArray' :: forall a b. PrimUnlifted a => (a -> b -> b) -> b -> UnliftedArray a -> b

Strict right-associated fold over the elements of an 'UnliftedArray.

foldlUnliftedArray :: forall a b. PrimUnlifted a => (b -> a -> b) -> b -> UnliftedArray a -> b

Lazy left-associated fold over the elements of an UnliftedArray.

foldlUnliftedArray' :: forall a b. PrimUnlifted a => (b -> a -> b) -> b -> UnliftedArray a -> b

Strict left-associated fold over the elements of an UnliftedArray.

foldlUnliftedArrayM' :: (PrimUnlifted a, Monad m) => (b -> a -> m b) -> b -> UnliftedArray a -> m b

Strict effectful left-associated fold over the elements of an UnliftedArray.

Traversals

traverseUnliftedArray_ :: (PrimUnlifted a, Applicative m) => (a -> m b) -> UnliftedArray a -> m ()

Effectfully traverse the elements of an UnliftedArray, discarding the resulting values.

itraverseUnliftedArray_ :: (PrimUnlifted a, Applicative m) => (Int -> a -> m b) -> UnliftedArray a -> m ()

Effectful indexed traversal of the elements of an UnliftedArray, discarding the resulting values.

Mapping

mapUnliftedArray :: (PrimUnlifted a, PrimUnlifted b) => (a -> b) -> UnliftedArray a -> UnliftedArray b

Map over the elements of an UnliftedArray.