Makes an immutable array using the underlying memory of the mutable array.

Please make sure that there are no other references to the mutable array lying around, so that it is never used after freezing it using unsafeFreeze. If the underlying array is mutated, the immutable promise is lost.

Pre-release

Similar to unsafeFreeze but uses rightSize on the mutable array first.

Makes a mutable array using the underlying memory of the immutable array.

Please make sure that there are no other references to the immutable array lying around, so that it is never used after thawing it using unsafeThaw. If the resulting array is mutated, any references to the older immutable array are mutated as well.

Pre-release

Create an Array of the given number of elements of type a from a read only pointer Ptr a. The pointer is not freed when the array is garbage collected. This API is unsafe for the following reasons:

1. The pointer must point to static pinned memory or foreign memory that does not require freeing..
2. The pointer must be legally accessible upto the given length.
3. To guarantee that the array is immutable, the contents of the address must be guaranteed to not change.

Unsafe

Pre-release

Create an Array Word8 of the given length from a static, read only machine address Addr#. See fromPtr for safety caveats.

A common use case for this API is to create an array from a static unboxed string literal. GHC string literals are of type Addr#, and must contain characters that can be encoded in a byte i.e. characters or literal bytes in the range from 0-255.

>>> import Data.Word (Word8)
>>> Array.fromAddr# 5 "hello world!"# :: Array Word8
[104,101,108,108,111]

>>> Array.fromAddr# 3 "\255\NUL\255"# :: Array Word8
[255,0,255]

See also: fromString#

Unsafe

Time complexity: O(1)

Pre-release

Generate a byte array from an Addr# that contains a sequence of NUL (0) terminated bytes. The array would not include the NUL byte. The address must be in static read-only memory and must be legally accessible up to and including the first NUL byte.

An unboxed string literal (e.g. "hello"#) is a common example of an Addr# in static read only memory. It represents the UTF8 encoded sequence of bytes terminated by a NUL byte (a CString) corresponding to the given unicode string.

>>> Array.fromCString# "hello world!"#
[104,101,108,108,111,32,119,111,114,108,100,33]

>>> Array.fromCString# "\255\NUL\255"#
[255]

See also: fromAddr#

Unsafe

Time complexity: O(n) (computes the length of the string)

Pre-release

Create an Array from a list. The list must be of finite size.

Since 0.7.0 (Streamly.Memory.Array)

Since: 0.8.0

Create an Array from the first N elements of a list. The array is allocated to size N, if the list terminates before N elements then the array may hold less than N elements.

Since 0.7.0 (Streamly.Memory.Array)

Since: 0.8.0

Create an Array from a list in reverse order. The list must be of finite size.

Unimplemented

Create an Array from the first N elements of a list in reverse order. The array is allocated to size N, if the list terminates before N elements then the array may hold less than N elements.

Unimplemented

Return element at the specified index without checking the bounds.

Unsafe because it does not check the bounds of the array.

Return element at the specified index without checking the bounds.

O(1) Get the byte length of the array.

Since: 0.7.0

O(1) Get the length of the array i.e. the number of elements in the array.

Since 0.7.0 (Streamly.Memory.Array)

Since: 0.8.0

Create two slices of an array without copying the original array. The specified index i is the first index of the second slice.

Since: 0.7.0

Unfold an array into a stream in reverse order.

Since: 0.8.0

Convert an Array into a stream.

Pre-release

Convert an Array into a stream in reverse order.

Pre-release

Convert an Array into a list.

Since 0.7.0 (Streamly.Memory.Array)

Since: 0.8.0

writeN n folds a maximum of n elements from the input stream to an Array.

Since 0.7.0 (Streamly.Memory.Array)

Since: 0.8.0

Like writeN but does not check the array bounds when writing. The fold driver must not call the step function more than n times otherwise it will corrupt the memory and crash. This function exists mainly because any conditional in the step function blocks fusion causing 10x performance slowdown.

Since: 0.7.0

writeNAligned alignment n folds a maximum of n elements from the input stream to an Array aligned to the given size.

Pre-release

writeNAlignedUnmanaged n folds a maximum of n elements from the input stream to an Array aligned to the given size and using unmanaged memory. This could be useful to allocate memory that we need to allocate only once in the lifetime of the program.

Pre-release

Fold the whole input to a single array.

Caution! Do not use this on infinite streams.

Since 0.7.0 (Streamly.Memory.Array)

Since: 0.8.0

arraysOf n stream groups the input stream into a stream of arrays of size n.

Use the "read" unfold instead.

flattenArrays = unfoldMany read

We can try this if there are any fusion issues in the unfold.

Use the "readRev" unfold instead.

flattenArrays = unfoldMany readRev

We can try this if there are any fusion issues in the unfold.