support GHC 9.6

flake.nix

@@ -17,10 +17,11 @@
     ghcs = {
       "865" = hsPkgs nixpkgs_2009 "ghc865";
       "884" = hsPkgs nixpkgs_2105 "ghc884";
-      "8107" = hsPkgs unstable "ghc8107";
-      "902" = hsPkgs unstable "ghc902";
-      "925" = hsPkgs unstable "ghc925";
-      "943" = hsPkgs unstable "ghc943";
+      "810" = hsPkgs unstable "ghc810";
+      "90" = hsPkgs unstable "ghc90";
+      "92" = hsPkgs unstable "ghc92";
+      "94" = hsPkgs unstable "ghc94";
+      "96" = hsPkgs unstable "ghc96";
     };
 
     mkPackages = version: {
@@ -29,27 +30,28 @@
     };
 
     defaultPackages = {
-      inherit (ghcs."902") polysemy polysemy-plugin;
-      default = ghcs."902".polysemy;
+      inherit (ghcs."92") polysemy polysemy-plugin;
+      default = ghcs."92".polysemy;
     };
 
     packages = foldl' (l: r: l // r) defaultPackages (map mkPackages (attrNames ghcs));
 
-    mkDevShell = ghc: ghc.shellFor {
+    mkDevShell = name: ghc: ghc.shellFor {
       packages = p: [p.polysemy p.polysemy-plugin];
       buildInputs = with ghc; [
         cabal-install
+      ] ++ unstable.lib.optionals (name != "96") [
         (ghc.pkgs.haskell.lib.dontCheck ghcid)
         haskell-language-server
       ];
     };
 
-    devShells = mapAttrs' (n: g: nameValuePair "ghc${n}" (mkDevShell g)) ghcs;
+    devShells = mapAttrs' (n: g: nameValuePair "ghc${n}" (mkDevShell n g)) ghcs;
 
   in {
     inherit packages;
 
-    devShells = devShells // { default = devShells.ghc902; };
+    devShells = devShells // { default = devShells.ghc92; };
 
     checks = packages;
   });

nix/overlay.nix

@@ -4,16 +4,23 @@
   compiler,
 }:
 let
-  overrides = pkgs: self: super:
+  pkgs = import nixpkgs { inherit system; };
+
+  overrides = self: super:
   let
     filter = pkgs.nix-gitignore.gitignoreSourcePure [./source-filter];
 
     c2n = name: src: pkgs.haskell.lib.disableLibraryProfiling (self.callCabal2nix name (filter src) {});
+
   in {
     polysemy = c2n "polysemy" ../.;
     polysemy-plugin = c2n "polysemy-plugin" ../polysemy-plugin;
+  } // pkgs.lib.optionalAttrs (compiler == "ghc96") {
+    type-errors = self.callHackageDirect {
+      pkg = "type-errors";
+      ver = "0.2.0.2";
+      sha256 = "sha256-z/QANg5jUhSc02IBVQEsg7QemiyV3XdwxN9K1CH2Myc=";
+    } {};
   };
-
-  pkgs = import nixpkgs { inherit system; };
 in
-  pkgs.haskell.packages.${compiler}.override { overrides = overrides pkgs; } // { inherit pkgs; }
+  pkgs.haskell.packages.${compiler}.override { inherit overrides; } // { inherit pkgs; }

package.yaml

@@ -23,8 +23,8 @@ dependencies:
 - syb >= 0.7 && < 0.8
 - stm >= 2 && < 3
 - template-haskell >= 2.12.0.0 && < 3
-- th-abstraction >= 0.3.1.0 && < 0.5
-- transformers >= 0.5.2.0 && < 0.6
+- th-abstraction >= 0.3.1.0 && < 0.6
+- transformers >= 0.5.2.0 && < 0.7
 - first-class-families >= 0.5.0.0 && < 0.9
 - unagi-chan >= 0.4.0.0 && < 0.5
 - async >= 2.2 && < 3
@@ -82,7 +82,7 @@ tests:
     - polysemy
     - inspection-testing >= 0.4.2 && < 0.6
     - hspec >= 2.6.0 && < 3
-    - doctest >= 0.16.0.1 && < 0.21
+    - doctest >= 0.16.0.1 && < 0.22
     - hspec-discover >= 2.0
     generated-other-modules:
     - Build_doctests

polysemy-plugin/package.yaml

@@ -22,7 +22,7 @@ dependencies:
 - ghc-tcplugins-extra >= 0.3 && < 0.5
 - polysemy >= 1.7
 - syb >= 0.7 && < 0.8
-- transformers >= 0.5.2.0 && < 0.6
+- transformers >= 0.5.2.0 && < 0.7
 - containers >= 0.5 && < 0.7
 
 custom-setup:
@@ -63,7 +63,7 @@ tests:
     - hspec >= 2.6.0 && < 3
     - should-not-typecheck >= 2.1.0 && < 3
     - inspection-testing >= 0.4.2 && < 0.6
-    - doctest >= 0.16.0.1 && < 0.21
+    - doctest >= 0.16.0.1 && < 0.22
     generated-other-modules:
     - Build_doctests
 

polysemy-plugin/polysemy-plugin.cabal

@@ -1,6 +1,6 @@
 cabal-version: 2.0
 
--- This file has been generated from package.yaml by hpack version 0.35.0.
+-- This file has been generated from package.yaml by hpack version 0.35.1.
 --
 -- see: https://github.com/sol/hpack
 
@@ -70,7 +70,7 @@ library
     , ghc-tcplugins-extra >=0.3 && <0.5
     , polysemy >=1.7
     , syb ==0.7.*
-    , transformers >=0.5.2.0 && <0.6
+    , transformers >=0.5.2.0 && <0.7
   default-language: Haskell2010
 
 test-suite polysemy-plugin-test
@@ -111,7 +111,7 @@ test-suite polysemy-plugin-test
   build-depends:
       base >=4.9 && <5
     , containers >=0.5 && <0.7
-    , doctest >=0.16.0.1 && <0.21
+    , doctest >=0.16.0.1 && <0.22
     , ghc >=8.6.5 && <10
     , ghc-tcplugins-extra >=0.3 && <0.5
     , hspec >=2.6.0 && <3
@@ -121,7 +121,7 @@ test-suite polysemy-plugin-test
     , polysemy-plugin
     , should-not-typecheck >=2.1.0 && <3
     , syb ==0.7.*
-    , transformers >=0.5.2.0 && <0.6
+    , transformers >=0.5.2.0 && <0.7
   default-language: Haskell2010
   if flag(corelint)
     ghc-options: -dcore-lint -dsuppress-all

polysemy-plugin/src/Polysemy/Plugin/Fundep.hs

@@ -52,6 +52,16 @@ import           Polysemy.Plugin.Fundep.Stuff
 import           Polysemy.Plugin.Fundep.Unification
 import           Polysemy.Plugin.Fundep.Utils
 
+#if __GLASGOW_HASKELL__ >= 906
+#define SUBST Subst
+#define GET_TYVAR getTyVar_maybe
+import           GHC.Core.TyCo.Subst (SUBST)
+import           GHC.Core.TyCo.Compare (eqType, nonDetCmpType)
+#else
+#define SUBST TCvSubst
+#define GET_TYVAR tcGetTyVar_maybe
+#endif
+
 #if __GLASGOW_HASKELL__ >= 900
 import           GHC.Builtin.Types.Prim (alphaTys)
 import           GHC.Plugins (idType, tyConClass_maybe, ppr, Outputable, sep, text, (<+>), parens, emptyUFM)
@@ -60,7 +70,7 @@ import           GHC.Tc.Plugin (TcPluginM, tcPluginIO)
 import           GHC.Tc.Types
 import           GHC.Tc.Types.Constraint
 import           GHC.Tc.Utils.Env (tcGetInstEnvs)
-import           GHC.Tc.Utils.TcType (tcSplitPhiTy, tcSplitTyConApp, tcGetTyVar_maybe, tcSplitAppTy_maybe)
+import           GHC.Tc.Utils.TcType (tcSplitPhiTy, tcSplitTyConApp, GET_TYVAR, tcSplitAppTy_maybe)
 import           GHC.Tc.Solver.Monad hiding (tcLookupClass)
 import           GHC.Core.Class (classTyCon)
 import           GHC.Core.InstEnv (lookupInstEnv, is_dfun)
@@ -80,14 +90,12 @@ import           MonadUtils (allM, anyM)
 import           TcEvidence
 import           TcPluginM (tcPluginIO)
 import           TcRnTypes
-import           TcType (tcSplitPhiTy, tcSplitTyConApp, tcGetTyVar_maybe, tcSplitAppTy_maybe)
+import           TcType (tcSplitPhiTy, tcSplitTyConApp, GET_TYVAR, tcSplitAppTy_maybe)
 import           TcSMonad hiding (tcLookupClass)
 import           Type
 import           TysPrim (alphaTys)
 #endif
 
-
-
 fundepPlugin :: TcPlugin
 fundepPlugin = TcPlugin
   { tcPluginInit =
@@ -193,12 +201,15 @@ findMatchingEffectIfSingular
                 True -> pure $ Just eff
                 False -> pure Nothing
 
-
 ------------------------------------------------------------------------------
 -- | @checkExtraEvidence givens subst c@ returns 'True' iff we can prove that
 -- the constraint @c@ holds under the substitution @subst@ in the context of
 -- @givens@.
-checkExtraEvidence :: Set PredType' -> TCvSubst -> PredType -> TcM Bool
+checkExtraEvidence ::
+  Set PredType' ->
+  SUBST ->
+  PredType ->
+  TcM Bool
 checkExtraEvidence givens subst = flip evalStateT givens . getInstance . substTy subst
 
 
@@ -240,8 +251,8 @@ mkWantedForce fc given = do
 skolemsForInterpreter :: Type -> Set TyVar
 skolemsForInterpreter ty =
   case tcSplitAppTy_maybe ty of
-    Just (tcGetTyVar_maybe -> Just skolem, _) -> S.singleton skolem
-    _ -> maybe mempty S.singleton $ tcGetTyVar_maybe ty
+    Just (GET_TYVAR -> Just skolem, _) -> S.singleton skolem
+    _ -> maybe mempty S.singleton $ GET_TYVAR ty
 
 
 ------------------------------------------------------------------------------

polysemy-plugin/src/Polysemy/Plugin/Fundep/Unification.hs

@@ -25,6 +25,14 @@ import           Unify
 import           GhcPlugins (Outputable, ppr, parens, text, (<+>))
 #endif
 
+#if __GLASGOW_HASKELL__ >= 906
+#define SUBST Subst
+import           GHC.Core.TyCo.Subst (SUBST)
+import           GHC.Core.TyCo.Compare (eqType, nonDetCmpType)
+#else
+#define SUBST TCvSubst
+#endif
+
 
 ------------------------------------------------------------------------------
 -- | The context in which we're attempting to solve a constraint.
@@ -64,7 +72,7 @@ unify
     :: SolveContext
     -> Type  -- ^ wanted
     -> Type  -- ^ given
-    -> Maybe TCvSubst
+    -> Maybe SUBST
 unify solve_ctx = tryUnifyUnivarsButNotSkolems skolems
   where
     skolems :: Set TyVar
@@ -81,7 +89,7 @@ unify solve_ctx = tryUnifyUnivarsButNotSkolems skolems
 #define APART Skolem
 #endif
 
-tryUnifyUnivarsButNotSkolems :: Set TyVar -> Type -> Type -> Maybe TCvSubst
+tryUnifyUnivarsButNotSkolems :: Set TyVar -> Type -> Type -> Maybe SUBST
 tryUnifyUnivarsButNotSkolems skolems goal inst =
   case tcUnifyTysFG
          (bool BINDME APART . flip S.member skolems)

polysemy.cabal

@@ -1,6 +1,6 @@
 cabal-version: 2.0
 
--- This file has been generated from package.yaml by hpack version 0.34.7.
+-- This file has been generated from package.yaml by hpack version 0.35.1.
 --
 -- see: https://github.com/sol/hpack
 
@@ -106,18 +106,18 @@ library
     , stm ==2.*
     , syb ==0.7.*
     , template-haskell >=2.12.0.0 && <3
-    , th-abstraction >=0.3.1.0 && <0.5
-    , transformers >=0.5.2.0 && <0.6
+    , th-abstraction >=0.3.1.0 && <0.6
+    , transformers >=0.5.2.0 && <0.7
     , type-errors >=0.2.0.0
     , unagi-chan >=0.4.0.0 && <0.5
+  default-language: Haskell2010
   if impl(ghc < 8.6)
     default-extensions:
         MonadFailDesugaring
         TypeInType
   if impl(ghc < 8.2.2)
     build-depends:
         unsupported-ghc-version >1 && <1
-  default-language: Haskell2010
 
 test-suite polysemy-test
   type: exitcode-stdio-1.0
@@ -167,7 +167,7 @@ test-suite polysemy-test
       async >=2.2 && <3
     , base >=4.9 && <5
     , containers >=0.5 && <0.7
-    , doctest >=0.16.0.1 && <0.21
+    , doctest >=0.16.0.1 && <0.22
     , first-class-families >=0.5.0.0 && <0.9
     , hspec >=2.6.0 && <3
     , hspec-discover >=2.0
@@ -177,12 +177,12 @@ test-suite polysemy-test
     , stm ==2.*
     , syb ==0.7.*
     , template-haskell >=2.12.0.0 && <3
-    , th-abstraction >=0.3.1.0 && <0.5
-    , transformers >=0.5.2.0 && <0.6
+    , th-abstraction >=0.3.1.0 && <0.6
+    , transformers >=0.5.2.0 && <0.7
     , type-errors >=0.2.0.0
     , unagi-chan >=0.4.0.0 && <0.5
+  default-language: Haskell2010
   if impl(ghc < 8.6)
     default-extensions:
         MonadFailDesugaring
         TypeInType
-  default-language: Haskell2010