Safe Haskell	None

Data.Yarr.Repr.Foreign

Synopsis

Documentation

data F Source

Foreign representation is the heart of Yarr framework.

Internally it holds raw pointer (Ptr), which makes indexing foreign arrays not slower than GHC's built-in primitive arrays, but without freeze/thaw boilerplate.

Foreign arrays are very permissible, for example you can easily use them as source and target of Loading operation simultaneously, achieving old good in-place C-style array modifying:

loadS fill (dmap sqrt arr) arr

Foreign arrays are intented to hold all Storable types and vectors of them (because there is a conditional instance of Storalbe class for Vectors of Storables too).

Instances

(Shape sh, Storable a) => UTarget F L sh a
(Shape sh, Storable a) => USource F L sh a
Shape sh => Regular F L sh a
DefaultFusion F D L sh
(Shape sh, Storable a) => Manifest F F L sh a
Shape sh => DefaultIFusion F L D SH sh
(Shape sh, Vector v e, Storable e) => UVecTarget F FS L sh v e
(Shape sh, Vector v e, Storable e) => UVecSource F FS L sh v e
(Shape sh, Vector v e, Storable e) => VecRegular F FS L sh v e
(Shape sh, Vector v e, Storable e) => UVecSource (SE F) F L sh v e
Shape sh => NFData (UArray F L sh a)

data FS Source

Foreign Slice representation, view slice representation for Foreign arrays.

To understand Foreign Slices, suppose you have standard image array of UArray F Dim2 (VecList N3 Word8) type.

It's layout in memory (with array indices):

  r g b | r g b | r g b | ...
 (0, 0)  (0, 1)  (0, 2)   ...

 let (VecList [reds, greens, blues]) = slices image
 -- reds, greens, blues :: UArray FS Dim2 Word8

Now blues just indexes each third byte on the same underlying memory block:

 ... b | ... b | ... b | ...
   (0, 0)  (0, 1)  (0, 2)...

Instances

(Shape sh, Storable e) => UTarget FS L sh e
(Shape sh, Storable e) => USource FS L sh e
Shape sh => Regular FS L sh e
DefaultFusion FS D L sh
Shape sh => DefaultIFusion FS L D SH sh
(Shape sh, Vector v e, Storable e) => UVecTarget F FS L sh v e
(Shape sh, Vector v e, Storable e) => UVecSource F FS L sh v e
(Shape sh, Vector v e, Storable e) => VecRegular F FS L sh v e
Shape sh => NFData (UArray FS L sh e)

There are also ForeignArray and ForeignSlice UArray family constructors, which aren't presented in the docs because Haddock doesn't support associated family constructors.

See source of Data.Yarr.Repr.Foreign module.

class Storable a

The member functions of this class facilitate writing values of primitive types to raw memory (which may have been allocated with the above mentioned routines) and reading values from blocks of raw memory. The class, furthermore, includes support for computing the storage requirements and alignment restrictions of storable types.

Memory addresses are represented as values of type Ptr a, for some a which is an instance of class Storable. The type argument to Ptr helps provide some valuable type safety in FFI code (you can't mix pointers of different types without an explicit cast), while helping the Haskell type system figure out which marshalling method is needed for a given pointer.

All marshalling between Haskell and a foreign language ultimately boils down to translating Haskell data structures into the binary representation of a corresponding data structure of the foreign language and vice versa. To code this marshalling in Haskell, it is necessary to manipulate primitive data types stored in unstructured memory blocks. The class Storable facilitates this manipulation on all types for which it is instantiated, which are the standard basic types of Haskell, the fixed size Int types (Int8, Int16, Int32, Int64), the fixed size Word types (Word8, Word16, Word32, Word64), StablePtr, all types from Foreign.C.Types, as well as Ptr.

Minimal complete definition: sizeOf, alignment, one of peek, peekElemOff and peekByteOff, and one of poke, pokeElemOff and pokeByteOff.

Instances

Storable Bool
Storable Char
Storable Double
Storable Float
Storable Int
Storable Int8
Storable Int16
Storable Int32
Storable Int64
Storable Word
Storable Word8
Storable Word16
Storable Word32
Storable Word64
Storable Fingerprint
Storable (StablePtr a)
Storable (Ptr a)
Storable (FunPtr a)
(Storable e, Vector v e) => Storable (v e)

data L Source

Linear load type index. UArrays with L load type index define linearIndex and linearWrite and leave index and write functions defined by default.

Instances

WorkIndex sh Int => PreferredWorkIndex L sh Int
(Shape sh, Storable e) => UTarget FS L sh e
(Shape sh, Storable a) => UTarget F L sh a
(Shape sh, NFData a) => UTarget MB L sh a
Shape sh => USource D L sh a
(Shape sh, Storable e) => USource FS L sh e
(Shape sh, Storable a) => USource F L sh a
(Shape sh, NFData a) => USource MB L sh a
(Shape sh, NFData a) => USource B L sh a
Shape sh => Regular D L sh a
Shape sh => Regular FS L sh e
Shape sh => Regular F L sh a
(Shape sh, NFData a) => Regular MB L sh a
(Shape sh, NFData a) => Regular B L sh a
DefaultFusion D D L sh
DefaultFusion FS D L sh
DefaultFusion F D L sh
DefaultFusion MB D L sh
DefaultFusion B D L sh
Fusion r D L sh
(Shape sh, Storable a) => Manifest F F L sh a
(Shape sh, NFData a) => Manifest B MB L sh a
Shape sh => DefaultIFusion D L D SH sh
Shape sh => DefaultIFusion FS L D SH sh
Shape sh => DefaultIFusion F L D SH sh
Shape sh => DefaultIFusion MB L D SH sh
Shape sh => DefaultIFusion B L D SH sh
(Shape sh, Vector v e, Storable e) => UVecTarget F FS L sh v e
(Shape sh, Vector v e) => UVecSource D D L sh v e
(Shape sh, Vector v e, Storable e) => UVecSource F FS L sh v e
(Shape sh, Vector v e) => VecRegular D D L sh v e
(Shape sh, Vector v e, Storable e) => VecRegular F FS L sh v e
Load r L tr SH sh a => RangeLoad r L tr SH sh a
Load r SH tr L sh a => RangeLoad r SH tr L sh a
Load r L tr L sh a => RangeLoad r L tr L sh a
(USource r L sh a, UTarget tr SH sh a) => Load r L tr SH sh a
(USource r SH sh a, UTarget tr L sh a) => Load r SH tr L sh a
(USource r L sh a, UTarget tr L sh a, WorkIndex sh Int) => Load r L tr L sh a
(VecLoad r slr L tr tslr SH sh v v2 e, RangeLoad slr L tslr SH sh e) => RangeVecLoad r slr L tr tslr SH sh v v2 e
(VecLoad r slr SH tr tslr L sh v v2 e, RangeLoad slr SH tslr L sh e) => RangeVecLoad r slr SH tr tslr L sh v v2 e
(VecLoad r slr L tr tslr L sh v v2 e, RangeLoad slr L tslr L sh e) => RangeVecLoad r slr L tr tslr L sh v v2 e
(UVecSource r slr L sh v e, UVecTarget tr tslr SH sh v2 e, Load slr L tslr SH sh e, ~ * (Dim v) (Dim v2)) => VecLoad r slr L tr tslr SH sh v v2 e
(UVecSource r slr SH sh v e, UVecTarget tr tslr L sh v2 e, Load slr SH tslr L sh e, ~ * (Dim v) (Dim v2)) => VecLoad r slr SH tr tslr L sh v v2 e
(UVecSource r slr L sh v e, UVecTarget tr tslr L sh v2 e, Load slr L tslr L sh e, ~ * (Dim v) (Dim v2)) => VecLoad r slr L tr tslr L sh v v2 e
(Shape sh, Vector v e, Storable e) => UVecSource (SE F) F L sh v e
(Shape sh, Vector v e, NFData e) => UVecSource (SE MB) MB L sh v e
(Shape sh, Vector v e, NFData e) => UVecSource (SE B) B L sh v e
Shape sh => NFData (UArray D L sh a)
Shape sh => NFData (UArray FS L sh e)
Shape sh => NFData (UArray F L sh a)
(Shape sh, NFData a) => NFData (UArray MB L sh a)
(Shape sh, NFData a) => NFData (UArray B L sh a)

newEmpty :: (Shape sh, Storable a, Integral a) => sh -> IO (UArray F L sh a)Source

O(1) allocates zero-initialized foreign array.

Needed because common new function allocates array with garbage.

toForeignPtr :: Shape sh => UArray F L sh a -> ForeignPtr aSource

O(1) Returns pointer to memory block used by the given foreign array.

May be useful to reuse memory if you don't longer need the given array in the program:

 brandNewData <-
    unsafeFromForeignPtr ext (castForeignPtr (toForeignPtr arr))

unsafeFromForeignPtr :: Shape sh => sh -> ForeignPtr a -> IO (UArray F L sh a)Source

O(1) Wraps foreign ptr into foreign array.

The function is unsafe because it simply don't (and can't) check anything about correctness of produced array.