Foreign.Marshal.StaticArray

This module defines StaticArray, a simple wrapper around arrays with their dimensions in the type. StaticArray provides Storable instances using the type-level dimensions. This eases writing FFI bindings to fixed-size native arrays. For example, StaticArray UArray 10 CInt has a Storable instance that is directly compatible with int foo[10] in native code.

Multidimensional native arrays are also supported. StaticArray UArray '(10,20,100) CUChar is compatible with unsigned char foo[10][20][100]. Note the leading ' before the tuple containing the dimensions. It marks it as a DataKinds promoted tuple, necessary to store the dimensions.

To operate on the contents of a StaticArray, use toArray. toArray returns the backing array with the correct type and index values already in place. For example, the result of toArray on a StaticArray UArray '(10,20,100) CUChar is a UArray (Int, Int, Int) CUChar with its bounds set to ((0,0,0),(9,19,99)).

Basic interface

data StaticArray backing dimensions elements

A minimal array wrapper that encodes the full dimensions of the array in the type. Intended for interfacing with (possibly-)multidimensional arrays of fixed size in native code.

The constructor is not exported to prevent creating a StaticArray with a size that doesn't match its dimensions.

Instances

Eq (backing (Index k dimensions) elements) => Eq (StaticArray k backing dimensions elements)

(IArray b e, IxStatic k d, Show e) => Show (StaticArray k b d e)

(IxStatic k d, Storable e, IArray UArray e, MArray IOUArray e IO) => Storable (StaticArray k UArray d e)

(IxStatic k d, Storable e, IArray b e) => Storable (StaticArray k b d e)

toArray :: StaticArray backing dimensions elements -> backing (Index dimensions) elements

Returns the backing value of this StaticArray.

staticBounds :: forall b d e. IxStatic d => StaticArray b d e -> (Index d, Index d)

Get the compile-time bounds from a StaticArray. Does not examine its argument.

staticArray :: (IArray b e, IxStatic d) => [(Index d, e)] -> StaticArray b d e

Create a new StaticArray from a list of indices and elements. This has all the semantic caveats of array, except that the bounds are as good as those provided by the IxStatic instance.

listStaticArray :: (IxStatic d, IArray b e) => [e] -> StaticArray b d e

Create a new StaticArray from a list of elements in index order. Implemented in terms of listArray, with the same caveats.