Foreign.Marshal.Array

base-4.3.1.0: Basic libraries

Portability | portable
Stability | provisional
Maintainer | ffi@haskell.org

Foreign.Marshal.Array

Contents

- Marshalling arrays
  - Allocation
  - Marshalling
  - Combined allocation and marshalling
  - Copying
  - Finding the length
  - Indexing

Description

Marshalling support: routines allocating, storing, and retrieving Haskell lists that are represented as arrays in the foreign language

Synopsis

- mallocArray :: Storable a => Int -> IO (Ptr a)
- mallocArray0 :: Storable a => Int -> IO (Ptr a)
- allocaArray :: Storable a => Int -> (Ptr a -> IO b) -> IO b
- allocaArray0 :: Storable a => Int -> (Ptr a -> IO b) -> IO b
- reallocArray :: Storable a => Ptr a -> Int -> IO (Ptr a)
- reallocArray0 :: Storable a => Ptr a -> Int -> IO (Ptr a)
- peekArray :: Storable a => Int -> Ptr a -> IO [a]
- peekArray0 :: (Storable a, Eq a) => a -> Ptr a -> IO [a]
- pokeArray :: Storable a => Ptr a -> [a] -> IO ()
- pokeArray0 :: Storable a => a -> Ptr a -> [a] -> IO ()
- newArray :: Storable a => [a] -> IO (Ptr a)
- newArray0 :: Storable a => a -> [a] -> IO (Ptr a)
- withArray :: Storable a => [a] -> (Ptr a -> IO b) -> IO b
- withArray0 :: Storable a => a -> [a] -> (Ptr a -> IO b) -> IO b
- withArrayLen :: Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b
- withArrayLen0 :: Storable a => a -> [a] -> (Int -> Ptr a -> IO b) -> IO b
- copyArray :: Storable a => Ptr a -> Ptr a -> Int -> IO ()
- moveArray :: Storable a => Ptr a -> Ptr a -> Int -> IO ()
- lengthArray0 :: (Storable a, Eq a) => a -> Ptr a -> IO Int
- advancePtr :: Storable a => Ptr a -> Int -> Ptr a

# Marshalling arrays

## Allocation

mallocArray :: Storable a => Int -> IO (Ptr a)

Allocate storage for the given number of elements of a storable type (like `Foreign.Marshal.Alloc.malloc`, but for multiple elements).

mallocArray0 :: Storable a => Int -> IO (Ptr a)

Like `mallocArray`, but add an extra position to hold a special termination element.

allocaArray :: Storable a => Int -> (Ptr a -> IO b) -> IO b

Temporarily allocate space for the given number of elements (like `Foreign.Marshal.Alloc.alloca`, but for multiple elements).

allocaArray0 :: Storable a => Int -> (Ptr a -> IO b) -> IO b

Like `allocaArray`, but add an extra position to hold a special termination element.

reallocArray :: Storable a => Ptr a -> Int -> IO (Ptr a)

Adjust the size of an array

reallocArray0 :: Storable a => Ptr a -> Int -> IO (Ptr a)

Adjust the size of an array including an extra position for the end marker.

## Marshalling

peekArray :: Storable a => Int -> Ptr a -> IO [a]

Convert an array of given length into a Haskell list. The implementation is tail-recursive and so uses constant stack space.

peekArray0 :: (Storable a, Eq a) => a -> Ptr a -> IO [a]

Convert an array terminated by the given end marker into a Haskell list

pokeArray :: Storable a => Ptr a -> [a] -> IO ()

Write the list elements consecutive into memory

pokeArray0 :: Storable a => a -> Ptr a -> [a] -> IO ()

Write the list elements consecutive into memory and terminate them with the given marker element

## Combined allocation and marshalling

newArray :: Storable a => [a] -> IO (Ptr a)

Write a list of storable elements into a newly allocated, consecutive sequence of storable values (like `Foreign.Marshal.Utils.new`, but for multiple elements).

newArray0 :: Storable a => a -> [a] -> IO (Ptr a)

Write a list of storable elements into a newly allocated, consecutive sequence of storable values, where the end is fixed by the given end marker

withArray :: Storable a => [a] -> (Ptr a -> IO b) -> IO b

Temporarily store a list of storable values in memory (like `Foreign.Marshal.Utils.with`, but for multiple elements).

withArray0 :: Storable a => a -> [a] -> (Ptr a -> IO b) -> IO b

Like `withArray`, but a terminator indicates where the array ends

withArrayLen :: Storable a => [a] -> (Int -> Ptr a -> IO b) -> IO b

Like `withArray`, but the action gets the number of values as an additional parameter

withArrayLen0 :: Storable a => a -> [a] -> (Int -> Ptr a -> IO b) -> IO b

Like `withArrayLen`, but a terminator indicates where the array ends

## Copying

(argument order: destination, source)

copyArray :: Storable a => Ptr a -> Ptr a -> Int -> IO ()

Copy the given number of elements from the second array (source) into the first array (destination); the copied areas may not overlap

moveArray :: Storable a => Ptr a -> Ptr a -> Int -> IO ()

Copy the given number of elements from the second array (source) into the first array (destination); the copied areas may overlap

## Finding the length

lengthArray0 :: (Storable a, Eq a) => a -> Ptr a -> IO Int

Return the number of elements in an array, excluding the terminator

## Indexing

advancePtr :: Storable a => Ptr a -> Int -> Ptr a

Advance a pointer into an array by the given number of elements