From 34ce6078ba001864fb2701cbfaa9e9748b27f026 Mon Sep 17 00:00:00 2001
From: George Thomas <georgefsthomas@gmail.com>
Date: Thu, 19 Feb 2026 11:21:38 +0000
Subject: [PATCH] wip

---
 generate-bindings   | 10 +++++++++-
 haskell/exe/Main.hs | 24 +++++++++++++++++++++---
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/generate-bindings b/generate-bindings
index 30d4b1b..786d2fd 100755
--- a/generate-bindings
+++ b/generate-bindings
@@ -3,6 +3,13 @@ set -euo pipefail
 
 # TODO this is a complete vibe-coded hack, but the header patching at least is crucial
 
+# TODO fully-vibed hack
+# we should do a few things quite differently anyway
+
+# generated Haskell code shouldn't be checked in as it's not portable
+# does the TH way of using `hs-bindgen` help here?
+# I guess we shouldn't check in the generated C header either
+
 # Generate Haskell FFI bindings from Rust source code.
 #
 # Pipeline: cargo build -> cbindgen -> patch header -> hs-bindgen
@@ -90,7 +97,8 @@ pending_enum && /^typedef [A-Za-z0-9_]+ / {
 }
 
 { print }
-' "$HEADER" > "${HEADER}.tmp" && mv "${HEADER}.tmp" "$HEADER"
+' "$HEADER" > "${HEADER}.tmp"
+mv "${HEADER}.tmp" "$HEADER"
 
 echo "  Patched header at $HEADER"
 
diff --git a/haskell/exe/Main.hs b/haskell/exe/Main.hs
index 0b25177..08278a5 100644
--- a/haskell/exe/Main.hs
+++ b/haskell/exe/Main.hs
@@ -1,14 +1,32 @@
 module Main (main) where
 
 import Data.ByteString
+import Data.Word
 import Foreign.C
 import GarnetRs
 import GarnetRs.Safe
 import HsBindgen.Runtime.PtrConst
+import Unsafe.Coerce
 
 main :: IO ()
 main = do
     useAsCString "Haskell" $ hello . unsafeFromPtr
-    hello_struct T{a = CBool 1, b = 42}
-    hello_shape $ Shape (Shape_Tag 0) $ set_shape_body_circle $ Circle_Body 3.14
-    hello_shape $ Shape (Shape_Tag 1) $ set_shape_body_rectangle $ Rectangle_Body 10.0 5.0
+    hello_struct $ convertT T'{a = True, b = 42}
+    hello_struct $ convertT T'{a = False, b = 42}
+    hello_shape $ convertShape $ Circle 3.14
+    hello_shape $ convertShape $ Rectangle 10.0 5.0
+
+data T' = T'
+    { a :: Bool
+    , b :: Word8
+    }
+convertT T'{a, b} =
+    -- T{a = CBool $ unsafeCoerce @Bool @Word8 a, b}
+    T{a = CBool $ fromIntegral $ fromEnum a, b}
+
+data Shape'
+    = Circle CDouble
+    | Rectangle CDouble CDouble
+convertShape = \case
+    Circle r -> Shape (Shape_Tag 0) $ set_shape_body_circle $ Circle_Body r
+    Rectangle w h -> Shape (Shape_Tag 1) $ set_shape_body_rectangle $ Rectangle_Body w h