Nix build support

default.nix

@@ -0,0 +1,21 @@
+# Development workflow
+# - Executing nix-build builds the packages
+# - Executing nix-shell returns a shell environment containing
+#   1. Haskell packages needed
+#   2. Hoogle files for packages
+#   3. cabal and ghcid installed
+{ pkgs ? import <unstable> {}
+}:
+pkgs.haskellPackages.developPackage {
+  root = ./.;
+  name = "blogng";
+  modifier = drv:
+    # add buildtools such as cabal
+    pkgs.haskell.lib.addBuildTools drv
+      (with pkgs.haskellPackages; [
+        cabal-install
+        ghcid
+        # install hoogle files for packages we use.
+        #(hoogleLocal {packages = drv.propagatedBuildInputs;})
+      ]);
+}