module Foreign.Storable.ATS
( ATSStorable (..)
, AsCString (..)
, Indexed (..)
) where
import Control.Composition
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as BSL
import Data.Data
import qualified Data.Text as T
import qualified Data.Text.Lazy as TL
import Data.Word
import Foreign.C.String
import Foreign.C.Types
import Foreign.Marshal.Alloc
import Foreign.Ptr
import qualified Foreign.Storable as C
import GHC.Generics
deriving instance Data CChar
deriving instance Data CInt
class AsCString a where
toCString :: a -> IO CString
instance AsCString String where
toCString = newCString
instance AsCString T.Text where
toCString = newCString . T.unpack
instance AsCString TL.Text where
toCString = newCString . TL.unpack
instance AsCString BS.ByteString where
toCString = flip BS.useAsCString pure
instance AsCString BSL.ByteString where
toCString = flip BS.useAsCString pure . BSL.toStrict
class Storable' f where
sizeOf' :: f a -> Int
alignment' :: f a -> Int
peek' :: Word8 -> Ptr (f a) -> IO (f a)
poke' :: Word8 -> Ptr (f a) -> f a -> IO ()
pokeByteOff' :: Ptr (f a) -> Int -> f a -> IO ()
pokeByteOff' = poke' 0 .* plusPtr
peekByteOff' :: Ptr (f a) -> Int -> IO (f a)
peekByteOff' = peek' 0 .* plusPtr
instance Storable' U1 where
sizeOf' = pure 0
alignment' = pure 0
poke' _ _ = pure undefined
peek' _ _ = pure undefined
instance Storable' V1 where
peek' = undefined
alignment' = undefined
poke' = undefined
sizeOf' = undefined
instance (Storable' a, Storable' b) => Storable' (a :*: b) where
sizeOf' _ = sizeOf' (undefined :: a x) + sizeOf' (undefined :: b x)
alignment' _ = gcd (alignment' (undefined :: a x)) (alignment' (undefined :: b x))
peek' n ptr = do
a <- peek' n (castPtr ptr)
(a :*:) <$> peekByteOff' (castPtr ptr) (sizeOf' a)
poke' n ptr (a :*: b) = mconcat
[ poke' n (castPtr ptr) a
, pokeByteOff' (castPtr ptr) (sizeOf' a) b ]
asIndex :: (Data a) => a -> Int
asIndex x = subtract 1 . length $ takeWhile (/= ix) cs
where ix = toConstr x
cs = dataTypeConstrs (dataTypeOf x)
sumHelper :: Storable' f => Word8 -> Ptr a -> f b -> IO ()
sumHelper n ptr val = do
bptr <- mallocBytes (sizeOf' val)
poke' n bptr val
C.poke (castPtr ptr) bptr
ptrSize :: Int
ptrSize = C.sizeOf (undefined :: (Ptr Word8))
instance (Storable' a, Storable' b) => Storable' (a :+: b) where
sizeOf' _ = 1 + ptrSize
alignment' _ = 1
peek' _ _ = undefined
poke' n ptr (L1 val) = mconcat
[ C.poke (castPtr ptr) n
, sumHelper n ptr val ]
poke' n ptr (R1 val) = mconcat
[ C.poke (castPtr ptr) n
, sumHelper n ptr val ]
instance (C.Storable a) => Storable' (K1 i a) where
sizeOf' _ = C.sizeOf (undefined :: a)
alignment' _ = C.alignment (undefined :: a)
peek' _ ptr = pure K1 <*> C.peek (castPtr ptr)
poke' _ ptr (K1 val) = C.poke (castPtr ptr) val
instance (Storable' a) => Storable' (M1 i c a) where
sizeOf' _ = sizeOf' (undefined :: a x)
alignment' _ = alignment' (undefined :: a x)
peek' n ptr = pure M1 <*> peek' n (castPtr ptr)
poke' n ptr (M1 val) = poke' n (castPtr ptr) val
instance C.Storable a => Indexed a where
index :: a -> Word8
index = pure 1
class Indexed a where
index :: a -> Word8
default index :: Data a => a -> Word8
index = fromIntegral . asIndex
instance (Generic a, Storable' (Rep a), Data a) => C.Storable a where
sizeOf _ = (sizeOf' . from) (undefined :: a)
alignment = C.sizeOf
poke ptr x = poke' (index x) (castPtr ptr) (from x)
peek = fmap to . peek' undefined . castPtr
class ATSStorable a where
readPtr :: C.Storable a => Ptr a -> IO a
readPtr = C.peek
writePtr :: C.Storable a => a -> IO (Ptr a)
writePtr val = do
ptr <- mallocBytes (C.sizeOf val)
C.poke ptr val
pure ptr