Initial import

flake.nix

@@ -0,0 +1,74 @@
+{
+  description = "Haskell file poger (Effective Haskell)";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs";
+
+    flake-utils.url = "github:numtide/flake-utils";
+
+    pre-commit-hooks.url = "github:cachix/pre-commit-hooks.nix";
+    pre-commit-hooks.inputs.nixpkgs.follows = "nixpkgs";
+  };
+
+  outputs = { self, nixpkgs, flake-utils, pre-commit-hooks }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        haskellPackages = pkgs.haskell.packages.ghc924;
+
+        jailbreakUnbreak = pkg:
+          pkgs.haskell.lib.doJailbreak (pkg.overrideAttrs (_: { meta = { }; }));
+
+        packageName = "hcat";
+      in {
+        packages.${packageName} = haskellPackages.callCabal2nix packageName self
+          rec {
+            # Dependency overrides go here
+          };
+
+        defaultPackage = self.packages.${system}.${packageName};
+
+        apps = {
+          # run with: nix run #.hcat
+          hcat = {
+            type = "app";
+            program = "${self.defaultPackage.${system}}/bin/hcat";
+          };
+
+          # run with: nix run
+          default = self.apps.${system}.hcat;
+        };
+
+        checks = {
+          pre-commit-check = pre-commit-hooks.lib.${system}.run {
+            src = ./.;
+            hooks = {
+              nixfmt.enable = true;
+              fourmolu.enable = true;
+              hpack.enable = true;
+              hlint.enable = true;
+            };
+          };
+        };
+
+        devShell = haskellPackages.shellFor {
+          inherit (self.checks.${system}.pre-commit-check) shellHook;
+
+          packages = p: [ self.defaultPackage.${system} ];
+
+          withHoogle = true;
+
+          buildInputs = with pkgs; [
+            haskellPackages.haskell-language-server
+            haskellPackages.fourmolu
+            cabal-install
+            ghcid
+            nixfmt
+            hpack
+            hlint
+          ];
+          inputsFrom = builtins.attrValues self.packages.${system};
+        };
+      });
+}