| Safe Haskell | None |
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Foreign.Marshal.StaticArray
Description
This module defines StaticArray, a simple wrapper around instances
of IArray with its dimensions encoded in the type. StaticArray
provides a Storable instance that uses the type-level dimensions,
and significantly eases writing FFI bindings to fixed-size native
arrays. For example, StaticArray UArray 10 CIntStorable
instance that is directly compatible with int foo[10] in native
code.
Multidimensional native arrays are also supported. StaticArray
UArray '(10,20,100) CUCharunsigned 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) CUCharUArray (Int, Int, Int) CUChar((0,0,0),(9,19,99)).
- data StaticArray backing dimensions elements
- type family Mutable a :: * -> * -> *
- toArray :: StaticArray backing dimensions elements -> backing (Bound dimensions) elements
- staticArray :: (Ix (Bound d), IArray b e, StaticSize d) => [(Bound d, e)] -> StaticArray b d e
- listStaticArray :: (StaticSize d, Ix (Bound d), IArray b e) => [e] -> StaticArray b d e
- class StaticSize d where
- type Bound d :: *
- extent :: StaticArray b d e -> (Bound d, Bound d)
- fromNat :: forall proxy n. SingI n => proxy n -> Int
Documentation
data StaticArray backing dimensions elements Source
A minimal wrapper for instances of IArray 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 (Bound k dimensions) elements) => Eq (StaticArray k backing dimensions elements) | |
| (IArray b e, Ix (Bound k d), Show e) => Show (StaticArray k b d e) | |
| (StaticSize k d, Ix (Bound k d), Storable e, IArray b e, MArray (Mutable b) e IO) => Storable (StaticArray k b d e) |
type family Mutable a :: * -> * -> *Source
The Mutable type family is used to associate instances of
IArray with instances of MArray that give non-copying
unsafeFreeze. This is used to increase the efficiency of peek
in StaticArray 's Storable instance.
If you're using an instance of IArray other than Array or
UArray, you'll need to add a type instance for your type. If it
supports non-copying unsafeFreeze, the type instance should
return the type constructor for the appropriate MArray
instance. Otherwise, just have it return IOArray
toArray :: StaticArray backing dimensions elements -> backing (Bound dimensions) elementsSource
Returns the backing Array of this StaticArray.
staticArray :: (Ix (Bound d), IArray b e, StaticSize d) => [(Bound d, e)] -> StaticArray b d eSource
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 StaticSize
instance.
listStaticArray :: (StaticSize d, Ix (Bound d), IArray b e) => [e] -> StaticArray b d eSource
Create a new StaticArray from a list of elements in index
order. Implemented in terms of listArray.
class StaticSize d whereSource
This class connects dimension description types with IArray
index types and values.
This module contains instances for types of kind Nat, types of
the promoted kind '[Nat], and promoted tuples of Nat values up
to 13 elements. For instances not relying on promoted data types,
see the Foreign.Marshal.StaticArray.Unpromoted module.
Methods
extent :: StaticArray b d e -> (Bound d, Bound d)Source
The concrete bounds for an array of this dimensionality. Implementations of this function should not examine their argument in any way.
Instances
fromNat :: forall proxy n. SingI n => proxy n -> IntSource
A conversion function for converting type-level naturals to
value-level. This is being exposed to aid in the creation of
additional StaticSize instances for those who might desire to do
so.
Haddock is currently eating the important qualification that the
type variable n must have the kind Nat. The SingI instance is
automatically fulfilled for all types of kind Nat. Its explicit
presence in the signature is an artifact of how GHC implements
dictionary passing and type erasure.