update

flake.nix

@@ -0,0 +1,42 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs = { self, nixpkgs, ... }@inputs:
+    let
+      supportedSystems = [
+        "aarch64-darwin" "aarch64-linux"
+        "x86_64-darwin" "x86_64-linux"
+      ];
+
+      each-system = f: nixpkgs.lib.genAttrs supportedSystems (system: f rec {
+	pkgs = import nixpkgs {
+          inherit system;
+        };
+	inherit (pkgs) lib;
+        inherit system;
+      });
+    in {
+      # Exposed as a REPL convenience.
+      _pkgs = each-system ({ pkgs, ... }: pkgs);
+
+      packages = each-system ({ pkgs, ... }: {
+        # default = pkgs.callPackage ./default.nix {};
+      });
+
+      devShells = each-system ({ pkgs, system, ... }: {
+	default = pkgs.haskellPackages.developPackage {
+          root = ./.;
+          modifier = drv:
+            pkgs.haskell.lib.addBuildTools
+              drv
+              (with pkgs; [
+                cabal-install
+                qbe
+                gcc
+              ]);
+	};
+      });
+    };
+}