Updating nix files to allow nix-build directly

Author: ggzor

default.nix

@@ -1,29 +1 @@
-let
-  sources = import ./nix/sources.nix;
-  pkgs = import sources.nixpkgs { inherit config; };
-  hls = import sources.all-hls { version = "0.9.0"; ghc = "8.8.4"; };
-
-  compilerVersion = "ghc884";
-  compilerSet = pkgs.haskell.packages."${compilerVersion}";
-
-  gitIgnore = pkgs.nix-gitignore.gitignoreSourcePure;
-  config = {
-    packageOverrides = super: let self = super.pkgs; in rec {
-      haskell = super.haskell // {
-        packageOverrides = self: super: {
-          turing-machines = super.callCabal2nix "turing-machines" (gitIgnore [./.gitignore] ./.) {};
-        };
-      };
-    };
-  };
-in {
-  inherit pkgs;
-  shell = compilerSet.shellFor {
-    packages = p: [p.turing-machines];
-    buildInputs = with pkgs; [
-      compilerSet.cabal-install
-      ormolu
-      hls
-    ];
-  };
-}
+(import ./project.nix).pkgs.haskellPackages.turing-machines

project.nix

@@ -0,0 +1,29 @@
+let
+  sources = import ./nix/sources.nix;
+  pkgs = import sources.nixpkgs { inherit config; };
+  hls = import sources.all-hls { version = "0.9.0"; ghc = "8.8.4"; };
+
+  compilerVersion = "ghc884";
+  compilerSet = pkgs.haskell.packages."${compilerVersion}";
+
+  gitIgnore = pkgs.nix-gitignore.gitignoreSourcePure;
+  config = {
+    packageOverrides = super: let self = super.pkgs; in rec {
+      haskell = super.haskell // {
+        packageOverrides = self: super: {
+          turing-machines = super.callCabal2nix "turing-machines" (gitIgnore [./.gitignore] ./.) {};
+        };
+      };
+    };
+  };
+in {
+  inherit pkgs;
+  shell = compilerSet.shellFor {
+    packages = p: [p.turing-machines];
+    buildInputs = with pkgs; [
+      compilerSet.cabal-install
+      ormolu
+      hls
+    ];
+  };
+}

shell.nix

@@ -1 +1 @@
-(import ./default.nix).shell
+(import ./project.nix).shell