blob: df455c70e73c6aeb86b3201d53427c15d774e6b2 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE KindSignatures #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeApplications #-}
module Data.Array.Strided.Array where
import qualified Data.List.NonEmpty as NE
import Data.Proxy
import qualified Data.Vector.Storable as VS
import Foreign.Storable
import GHC.TypeLits
data Array (n :: Nat) a = Array
{ arrShape :: ![Int]
, arrStrides :: ![Int]
, arrOffset :: !Int
, arrValues :: !(VS.Vector a)
}
-- | Takes a vector in normalised order (inner dimension, i.e. last in the
-- list, iterates fastest).
arrayFromVector :: forall a n. (Storable a, KnownNat n) => [Int] -> VS.Vector a -> Array n a
arrayFromVector sh vec
| VS.length vec == shsize
, length sh == fromIntegral (natVal (Proxy @n))
= Array sh strides 0 vec
| otherwise = error $ "arrayFromVector: Shape " ++ show sh ++ " does not match vector length " ++ show (VS.length vec)
where
shsize = product sh
strides = NE.tail (NE.scanr (*) 1 sh)
arrayFromConstant :: (Storable a, KnownNat n) => [Int] -> a -> Array n a
arrayFromConstant sh x = Array sh (0 <$ sh) 0 (VS.singleton x)
arrayRevDims :: [Bool] -> Array n a -> Array n a
arrayRevDims bs (Array sh strides offset vec)
| length bs == length sh =
Array sh
(zipWith (\b s -> if b then -s else s) bs strides)
(offset + sum (zipWith3 (\b n s -> if b then (n - 1) * s else 0) bs sh strides))
vec
| otherwise = error $ "arrayRevDims: " ++ show (length bs) ++ " booleans given but rank " ++ show (length sh)
|
