Reformat all projects; switch to overlay format

elixir/flake.nix

@@ -6,32 +6,27 @@
     nixpkgs.url = "github:NixOS/nixpkgs";
   };
 
-  outputs = { self, flake-utils, nixpkgs }:
+  outputs =
+    { self
+    , flake-utils
+    , nixpkgs
+    }:
+
     flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+      devShell = pkgs.mkShell {
+        buildInputs = (with pkgs; [ elixir ]) ++
+          pkgs.lib.optionals (pkgs.stdenv.isLinux) (with pkgs; [ gigalixir inotify-tools libnotify ]) ++ # Linux only
+          pkgs.lib.optionals (pkgs.stdenv.isDarwin) (with pkgs; [ terminal-notifier ]) ++ # macOS only
+          (with pkgs.darwin.apple_sdk.frameworks; [ CoreFoundation CoreServices ]);
 
-        inherit (pkgs)
-          darwin gigalixir inotify-tools libnotify mkShell terminal-notifier;
-        inherit (pkgs.beam.packages.erlangR25) elixir elixir_ls;
-        inherit (pkgs.darwin.apple_sdk.frameworks) CoreFoundation CoreServices;
-        inherit (pkgs.lib) optionals;
-        inherit (pkgs.stdenv) isDarwin isLinux;
-
-        linuxDeps = optionals isLinux [ gigalixir inotify-tools libnotify ];
-        darwinDeps = optionals isDarwin [ terminal-notifier ]
-          ++ [ CoreFoundation CoreServices ];
-      in
-      {
-        devShells = {
-          default = mkShell {
-            buildInputs = [ elixir elixir_ls ] ++ linuxDeps ++ darwinDeps;
-
-            shellHook = ''
-              ${elixir}/bin/mix --version
-              ${elixir}/bin/iex --version
-            '';
-          };
-        };
-      });
+        shellHook = ''
+          ${pkgs.elixir}/bin/mix --version
+          ${pkgs.elixir}/bin/iex --version
+        '';
+      };
+    });
 }