flake copied over from puzzld

flake.nix

@@ -0,0 +1,43 @@
+{
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        t = pkgs.lib.trivial;
+        hl = pkgs.haskell.lib;
+
+        name = "puzzld";
+
+        project = devTools:
+          let addBuildTools = (t.flip hl.addBuildTools) devTools;
+          in pkgs.haskellPackages.developPackage {
+            root = pkgs.lib.sourceFilesBySuffices ./. [ ".cabal" ".hs" "LICENSE" ];
+            name = name;
+            returnShellEnv = !(devTools == [ ]);
+
+            modifier = (t.flip t.pipe) [
+              addBuildTools
+              hl.dontHaddock
+              hl.enableStaticLibraries
+              hl.justStaticExecutables
+              hl.disableLibraryProfiling
+              hl.disableExecutableProfiling
+            ];
+          };
+
+      in {
+        packages.puzzle-draw = project [ ];
+
+        defaultPackage = self.packages.${system}.puzzle-draw;
+
+        devShell = project (with pkgs.haskellPackages; [
+          pkgs.haskellPackages.cabal-fmt
+          pkgs.haskellPackages.cabal-install
+        ]);
+      });
+}