Add a nix flake

.gitignore

@@ -73,3 +73,9 @@ doc/icfp-2012.html
 download/*.html
 gf-book/index.html
 src/www/gf-web-api.html
+.devenv
+.direnv
+result
+.vscode
+.envrc
+.pre-commit-config.yaml

flake.nix

@@ -0,0 +1,110 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.05";
+    systems.url = "github:nix-systems/default";
+    devenv.url = "github:cachix/devenv";
+  };
+
+  nixConfig = {
+    extra-trusted-public-keys =
+      "devenv.cachix.org-1:w1cLUi8dv3hnoSPGAuibQv+f9TZLr6cv/Hm9XgU50cw=";
+    extra-substituters = "https://devenv.cachix.org";
+  };
+
+  outputs = { self, nixpkgs, devenv, systems, ... }@inputs:
+    let forEachSystem = nixpkgs.lib.genAttrs (import systems);
+    in {
+      packages = forEachSystem (system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+          haskellPackages = pkgs.haskell.packages.ghc925.override {
+            overrides = self: _super: {
+              cgi = pkgs.haskell.lib.unmarkBroken (pkgs.haskell.lib.dontCheck
+                (self.callHackage "cgi" "3001.5.0.1" { }));
+            };
+          };
+
+        in {
+          devenv-up = self.devShells.${system}.default.config.procfileScript;
+          gf = pkgs.haskell.lib.overrideCabal
+            (haskellPackages.callCabal2nixWithOptions "gf" self "--flag=-server"
+              { }) (_old: {
+                # Fix utf8 encoding problems
+                patches = [
+                  # Already applied in master
+                  # (
+                  #   pkgs.fetchpatch {
+                  #     url = "https://github.com/anka-213/gf-core/commit/6f1ca05fddbcbc860898ddf10a557b513dfafc18.patch";
+                  #     sha256 = "17vn3hncxm1dwbgpfmrl6gk6wljz3r28j191lpv5zx741pmzgbnm";
+                  #   }
+                  # )
+                  ./nix/expose-all.patch
+                  ./nix/revert-new-cabal-madness.patch
+                ];
+                jailbreak = true;
+                # executableSystemDepends = [
+                #   (pkgs.ncurses.override { enableStatic = true; })
+                # ];
+                # executableHaskellDepends = [ ];
+              });
+        });
+
+      devShells = forEachSystem (system:
+        let pkgs = nixpkgs.legacyPackages.${system};
+
+        in with pkgs.darwin.apple_sdk.frameworks;
+        let
+          darwinPkgs =
+
+            if pkgs.stdenv.isDarwin then [ Cocoa pkgs.clang ] else [ ];
+        in {
+
+          default = devenv.lib.mkShell {
+            inherit inputs pkgs;
+            modules = [{
+              # https://devenv.sh/basics/
+              env.GREET = "devenv";
+
+              # https://devenv.sh/packages/
+              packages = [ pkgs.git pkgs.llvm ] ++ darwinPkgs;
+
+              # https://devenv.sh/scripts/
+              scripts.hello.exec = "echo hello from $GREET";
+
+              enterShell = ''
+                hello
+                git --version
+              '';
+
+              languages.haskell = {
+                enable = true;
+                # HLS fails to build on darwin and 9.2.5
+                languageServer = null;
+                package = pkgs.haskell.compiler.ghc925;
+              };
+
+              # https://devenv.sh/pre-commit-hooks/
+              pre-commit.hooks = {
+                # lint shell scripts
+                shellcheck.enable = true;
+                markdownlint.enable = true;
+                # lint nix
+                nixfmt.enable = true;
+                deadnix.enable = true;
+                nil.enable = true;
+                # statix.enable = true;
+                # format haskell
+                # ormolu.enable = true;
+                # cabal-fmt.enable = true;
+                # lint haskell
+                # hlint.enable = true;
+              };
+              # https://devenv.sh/processes/
+              # processes.ping.exec = "ping example.com";
+
+              # See full reference at https://devenv.sh/reference/options/
+            }];
+          };
+        });
+    };
+}

gf.cabal

@@ -73,7 +73,7 @@ library
   build-depends:
     -- GHC 8.0.2 to GHC 8.10.4
     array >= 0.5.1 && < 0.6,
-    base >= 4.9.1 && < 4.17,
+    base >= 4.9.1 && < 4.18,
     bytestring >= 0.10.8 && < 0.12,
     containers >= 0.5.7 && < 0.7,
     exceptions >= 0.8.3 && < 0.11,

nix/expose-all.patch

@@ -0,0 +1,12 @@
+diff --git a/gf.cabal b/gf.cabal
+index 0076e7638..8d3fe4b49 100644
+--- a/gf.cabal
++++ b/gf.cabal
+@@ -168,7 +168,6 @@ Library
+     GF.Text.Lexing
+     GF.Grammar.Canonical
+
+-  other-modules:
+     GF.Main
+     GF.Compiler
+     GF.Interactive