From b7bbd5db4a12b378640a8c14209d0ed2105914c0 Mon Sep 17 00:00:00 2001
From: Bas van Dijk <bas@dfinity.org>
Date: Fri, 20 May 2022 18:41:25 +0200
Subject: [PATCH] Preparation for GHC-9.0 (#78)

This fixes some would-be warnings in GHC-9.0
that we're going to switch to once
https://github.com/dfinity/ic-hs/pull/76 is merged.
---
 src/IC/Purify.hs              | 3 ++-
 src/IC/Test/Agent.hs          | 3 +--
 src/IC/Wasm/Winter/Persist.hs | 5 +++--
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/IC/Purify.hs b/src/IC/Purify.hs
index 1789b61e..d85a18c2 100644
--- a/src/IC/Purify.hs
+++ b/src/IC/Purify.hs
@@ -7,11 +7,12 @@ module IC.Purify where
 
 import Control.Monad.ST
 import Data.Functor
+import Data.Kind (Type)
 import Data.Either
 import Data.Bifunctor
 
 class SnapshotAble i where
-  type SnapshotOf i :: *
+  type SnapshotOf i :: Type
   persist :: i s -> ST s (SnapshotOf i)
   recreate :: SnapshotOf i -> ST s (i s)
 
diff --git a/src/IC/Test/Agent.hs b/src/IC/Test/Agent.hs
index 9c319900..f8f6c26c 100644
--- a/src/IC/Test/Agent.hs
+++ b/src/IC/Test/Agent.hs
@@ -44,7 +44,6 @@ import Numeric.Natural
 import Data.Char
 import Test.Tasty.HUnit
 import Test.Tasty.Options
-import Control.Monad.Trans
 import Control.Monad.Except
 import Control.Concurrent
 import Control.Exception (catch)
@@ -128,7 +127,7 @@ connect :: String -> Int -> IO ReplWrapper
 connect ep tp = do
     agentConfig <- makeAgentConfig ep tp
     let ?agentConfig = agentConfig
-    return (R id)
+    return (R $ \x -> x)
 
 -- Yes, implicit arguments are frowned upon. But they are also very useful.
 
diff --git a/src/IC/Wasm/Winter/Persist.hs b/src/IC/Wasm/Winter/Persist.hs
index fc8119cd..cf782881 100644
--- a/src/IC/Wasm/Winter/Persist.hs
+++ b/src/IC/Wasm/Winter/Persist.hs
@@ -27,6 +27,7 @@ import qualified Data.IntMap as IM
 import qualified Data.Map.Lazy as M
 import qualified Data.Vector as V
 import Data.ByteString.Lazy (ByteString)
+import Data.Kind (Type)
 
 import qualified IC.Canister.StableMemory as Stable
 
@@ -56,8 +57,8 @@ resumeMemory :: W.MemoryInst (ST s) -> ByteString -> ST s ()
 resumeMemory i p = resume i p
 
 class Monad (M a) => Persistable a where
-  type Persisted a :: *
-  type M a :: * -> *
+  type Persisted a :: Type
+  type M a :: Type -> Type
   persist :: a -> M a (Persisted a)
   resume :: a -> Persisted a -> M a ()