Rewrite flake (fix overlay)

flake.nix

@@ -6,102 +6,98 @@
 
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/dbc68fa4bb132d990945d39801b0d7f2ba15b08f";
-    flake-utils.url = "github:numtide/flake-utils";
     flake-compat = {
       url = "github:edolstra/flake-compat";
       flake = false;
     };
   };
 
-  outputs = { self, nixpkgs, flake-utils, flake-compat }: flake-utils.lib.eachDefaultSystem
-    (system:
-      let
-        pkgs = nixpkgs.legacyPackages.${system};
+  outputs = {
+    self,
+    nixpkgs,
+    ...
+  }: let
+    inherit (nixpkgs) lib;
+    defaultSystems = [
+      "aarch64-linux"
+      "aarch64-darwin"
+      "x86_64-darwin"
+      "x86_64-linux"
+    ];
+    genSystems = lib.genAttrs defaultSystems;
+  in {
+    templates = {
+      vscodium-with-extensions = {
+        path = ./template;
+        description = "VSCodium with extensions";
+      };
+    };
 
-        loadGenerated = set:
-          with builtins; with pkgs; let
-            generated = import ./data/generated/${set}.nix {
-              inherit fetchurl fetchFromGitHub;
-              fetchgit = fetchGit;
-            };
+    extensions =
+      genSystems (system:
+        self.overlays.default null nixpkgs.legacyPackages.${system});
 
-            groupedByPublisher = (groupBy (e: e.publisher) (attrValues generated));
-            pkgDefinition = {
-              open-vsx = e: with e; with vscode-utils; {
-                inherit name;
-                value = buildVscodeMarketplaceExtension {
-                  vsix = src;
-                  mktplcRef = {
-                    inherit version;
-                    publisher = publisher;
-                    name = name;
-                  };
-                  meta = with lib; {
-                    inherit changelog downloadPage homepage;
-                    license = licenses.${license};
-                  };
+    overlays = {
+      default = _: prev: let
+        utils = prev.vscode-utils;
+        loadGenerated = path:
+          lib.pipe path [
+            (path:
+              import path {
+                inherit (prev) fetchurl fetchFromGitHub;
+                fetchgit = prev.fetchGit;
+              })
+            (lib.mapAttrsToList (_: extension: {
+              inherit (extension) name;
+              value = utils.buildVscodeMarketplaceExtension {
+                vsix = extension.src;
+                mktplcRef = {
+                  inherit (extension) name publisher version;
                 };
               };
-              vscode-marketplace = e: with e; with vscode-utils; {
-                inherit name;
-                value = buildVscodeMarketplaceExtension {
-                  vsix = src;
-                  mktplcRef = {
-                    inherit version;
-                    publisher = publisher;
-                    name = name;
-                  };
-                };
-              };
-            };
-          in
-          mapAttrs (_: val: listToAttrs (map pkgDefinition.${set} val)) groupedByPublisher;
+            }))
+            (builtins.groupBy ({value, ...}: value.vscodeExtPublisher))
+            (builtins.mapAttrs (_: lib.listToAttrs))
+          ];
+      in {
+        vscode-marketplace = loadGenerated ./data/generated/vscode-marketplace.nix;
+        open-vsx = loadGenerated ./data/generated/open-vsx.nix;
+      };
+    };
 
-        extensions = {
-          vscode-marketplace = loadGenerated "vscode-marketplace";
-          open-vsx = loadGenerated "open-vsx";
-        };
+    packages = genSystems (system: let
+      pkgs = nixpkgs.legacyPackages.${system};
 
-        vscodiumWithExtensions =
-          let
-            inherit (pkgs) vscode-with-extensions vscodium;
-            vscodium_ =
-              (vscode-with-extensions.override {
-                vscode = vscodium;
-                vscodeExtensions = builtins.attrValues {
-                  inherit (extensions.vscode-marketplace.golang) go;
-                  inherit (extensions.vscode-marketplace.vlanguage) vscode-vlang;
-                };
-              });
-          in
-          vscodium_ // {
-            meta = (builtins.removeAttrs vscodium_.meta [ "description" ]) // {
-              longDescription = ''
-                This is a sample `VSCodium` (= `VS Code` without proprietary stuff) with a couple of extensions.
-
-                The [repo](https://github.com/nix-community/nix-vscode-extensions) provides
-                `VS Code Marketplace` (~40K) and `Open VSX` (~3K) extensions as `Nix` expressions.
+      # overrideAttrs is avoided so that Nix can still hit binary cache
+      examplePackage = pkgs.vscode-with-extensions.override {
+        vscode = pkgs.vscodium;
+        vscodeExtensions = with self.extensions.${system}.vscode-marketplace; [
+          golang.go
+          vlanguage.vscode-vlang
+        ];
+      };
+      examplePackage' =
+        examplePackage
+        // {
+          meta =
+            (removeAttrs examplePackage.meta ["description"])
+            // {
+              longDescription = lib.mdDoc ''
+                This is a sample overridden VSCodium (FOSS fork of VS Code) with a couple extensions.
+                You can override this package and set `vscodeExtensions` to a list of extension
+                derivations, namely those provided by this flake.
+
+                The [repository] provides about 40K extensions from [Visual Studio Marketplace]
+                and another ~3K from [Open VSX Registry].
+
+                [repository]: https://github.com/nix-community/nix-vscode-extensions
+                [Visual Studio Marketplace]: https://marketplace.visualstudio.com/vscode
+                [Open VSX Registry]: https://open-vsx.org/
               '';
             };
-          };
-      in
-      {
-        packages = {
-          inherit vscodiumWithExtensions;
         };
-        inherit extensions;
-      }
-    ) // {
-    overlays.default = final: prev: {
-      vscode-extensions = self.extensions.${prev.system};
-    };
-  }
-  // {
-    templates = {
-      default = {
-        path = ./template;
-        description = "VSCodium with extensions";
-      };
-    };
+    in {
+      vscodium-with-extensions = examplePackage';
+    });
   };
 }