garnet/exe/GarnetRs/Wrapped.hs
2026-02-19 20:44:04 +00:00

70 lines
1.9 KiB
Haskell

-- TODO automate this sort of high level wrapper boilerplate
-- or look at upstream plans: https://github.com/well-typed/hs-bindgen/issues?q=state%3Aopen%20label%3A%22highlevel%22
module GarnetRs.Wrapped (
T (..),
Shape (..),
BTree (..),
hello,
helloStruct,
helloShape,
add,
sumTree,
) where
import Data.ByteString
import Data.Word
import Foreign
import Foreign.C
import GarnetRs qualified as Raw
import GarnetRs.Safe qualified as Raw
import HsBindgen.Runtime.PtrConst
data T = T
{ a :: Bool
, b :: Word8
}
convertT :: T -> Raw.T
convertT T{a, b} = Raw.T{a = fromBool a, b}
data Shape
= Circle CDouble
| Rectangle CDouble CDouble
convertShape :: Shape -> Raw.Shape
convertShape = \case
Circle r -> Raw.Shape Raw.Circle $ Raw.set_shape_body_circle $ Raw.Circle_Body r
Rectangle w h -> Raw.Shape Raw.Rectangle $ Raw.set_shape_body_rectangle $ Raw.Rectangle_Body w h
data BTree a
= Leaf a
| Fork (BTree a) (BTree a)
withBTree :: BTree Int64 -> (Raw.BTree -> IO a) -> IO a
withBTree = flip \f -> \case
Leaf v ->
f $ Raw.BTree Raw.Leaf $ Raw.set_bTree_body_leaf $ Raw.Leaf_Body v
Fork l r ->
withBTree l \lRaw ->
withBTree r \rRaw ->
alloca \lPtr ->
alloca \rPtr -> do
poke lPtr lRaw
poke rPtr rRaw
f
. Raw.BTree Raw.Fork
. Raw.set_bTree_body_fork
$ Raw.Fork_Body (unsafeFromPtr lPtr) (unsafeFromPtr rPtr)
hello :: ByteString -> IO ()
hello s = useAsCString s $ Raw.hello . unsafeFromPtr
helloStruct :: T -> IO ()
helloStruct = Raw.hello_struct . convertT
helloShape :: Shape -> IO ()
helloShape = Raw.hello_shape . convertShape
add :: Int64 -> Int64 -> Int64
add = Raw.add
sumTree :: BTree Int64 -> IO Int64
sumTree = flip withBTree Raw.sum_tree