use template haskell

flake.nix

@@ -0,0 +1,32 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    hs-bindgen = {
+      url = "github:well-typed/hs-bindgen/release-0.1-alpha2";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+  outputs = {
+    self,
+    nixpkgs,
+    hs-bindgen,
+    ...
+  }: let
+    pkgs = import nixpkgs {
+      system = "x86_64-linux";
+      overlays = [hs-bindgen.overlays.default];
+    };
+  in {
+    devShells.x86_64-linux.default = pkgs.mkShell {
+      stdenv = pkgs.clangStdenv;
+      inputsFrom = [self.packages.x86_64-linux.default];
+      packages = [
+        pkgs.cabal-install
+        pkgs.haskellPackages.haskell-language-server
+        pkgs.haskellPackages.cabal-gild
+        hs-bindgen.packages.x86_64-linux.hsBindgenHook
+      ];
+    };
+    packages.x86_64-linux.default = pkgs.haskellPackages.callCabal2nix "hs-rgfw" ./. {};
+  };
+}