Nix build circuit-notation for all Clash-GHC supported versions

flake.nix

@@ -6,47 +6,71 @@
   outputs = { self, flake-utils, clash-compiler, ... }:
     flake-utils.lib.eachDefaultSystem (system:
       let
-        # What version of the GHC compiler to use
-        compiler-version = clash-compiler.ghcVersion.${system};
-
-        pkgs = (import clash-compiler.inputs.nixpkgs {
-          inherit system;
-        }).extend clash-compiler.overlays.${compiler-version};
-        clash-pkgs = pkgs."clashPackages-${compiler-version}";
-
-        overlay = final: prev: {
-          circuit-notation = prev.developPackage {
-            root = ./.;
-            overrides = _: _: final;
-          };
-        };
-
-        hs-pkgs = clash-pkgs.extend overlay;
+        # The package to expose as 'default'
+        default-package = "circuit-notation";
+        # The 'default' version of ghc to use
+        default-version = clash-compiler.ghcVersion.${system};
+        # A list of all ghc versions this package supports
+        supported-versions = clash-compiler.supportedGhcVersions.${system};
+
+        all-overlays = builtins.listToAttrs (builtins.map (compiler-version:
+          let
+            overlay = final: prev: {
+              circuit-notation = prev.developPackage {
+                root = ./.;
+                overrides = _: _: final;
+              };
+            };
+          in
+            { name = compiler-version; value = overlay; }
+          ) supported-versions);
+
+        all-hs-pkgs = builtins.mapAttrs (compiler-version: overlay:
+          let
+            pkgs = (import clash-compiler.inputs.nixpkgs {
+              inherit system;
+            }).extend clash-compiler.overlays.${compiler-version};
+            clash-pkgs = pkgs."clashPackages-${compiler-version}";
+
+            hs-pkgs = clash-pkgs.extend overlay;
+          in
+            hs-pkgs
+          ) all-overlays;
+
+        all-shells = builtins.mapAttrs (_: hs-pkgs:
+          hs-pkgs.shellFor {
+            packages = p: [
+              p.circuit-notation
+            ];
+
+            nativeBuildInputs =
+              [
+                # Haskell stuff
+                hs-pkgs.cabal-install
+                hs-pkgs.cabal-plan
+                hs-pkgs.haskell-language-server
+                hs-pkgs.fourmolu
+              ]
+            ;
+          }) all-hs-pkgs;
+
+        all-packages = builtins.mapAttrs (_: hs-pkgs:
+          {
+            circuit-notation = hs-pkgs.circuit-notation;
+
+            default = hs-pkgs.${default-package};
+          }) all-hs-pkgs;
       in
       {
-        # Expose the overlay which adds circuit-notation
+        # Expose the overlay of each supported version which adds circuit-notation
         # The base of the overlay is clash-pkgs
-        overlays.default = overlay;
-
-        devShells.default = hs-pkgs.shellFor {
-          packages = p: [
-            p.circuit-notation
-          ];
-
-          nativeBuildInputs = 
-            [
-              # Haskell stuff
-              hs-pkgs.cabal-install
-              hs-pkgs.cabal-plan
-              hs-pkgs.haskell-language-server
-              hs-pkgs.fourmolu
-            ]
-          ;
-        };
-        packages = {
-          circuit-notation = hs-pkgs.circuit-notation;
-
-          default = hs-pkgs.circuit-notation;
-        };
+        overlays = all-overlays // { default = all-overlays.${default-version}; };
+
+        # A devShell for each supported version
+        devShells = all-shells // { default = all-shells.${default-version}; };
+
+        # The default directly refers to the default package of the default ghc version of this flake
+        # All other entries aren't packages, they're a set of packages for each supported ghc version
+        packages = all-packages // { default = all-packages.${default-version}.${default-package}; };
       });
 }