Merge pull request #6 from adetokunbo/use-dev-dot-nix

Use dev.nix to simplify future nix dev updates

.envrc

@@ -2,4 +2,4 @@ if ! has nix_direnv_version || ! nix_direnv_version 2.1.1; then
     source_url "https://raw.githubusercontent.com/nix-community/nix-direnv/2.1.1/direnvrc" "sha256-b6qJ4r34rbE23yWjMqbmu3ia2z4b2wIlZUksBke/ol0="
 fi
 use nix
-nix_direnv_watch_file cabal.project mem-info.cabal
+watch_file cabal.project mem-info.cabal h8x.nix dev.nix

default.nix

@@ -1,17 +1,13 @@
 let
-  pkgsNix = import ./h8x.nix;
+  dev = import ./dev.nix;
+  pkgs-nix = import ./h8x.nix;
 in
-{ pkgs ? pkgsNix
+{ pkgs ? pkgs-nix
 } : pkgs.haskell-nix.cabalProject {
   # 'cleanGit' cleans a source directory based on the files known by git
   src = pkgs.haskell-nix.haskellLib.cleanGit {
     name = "mem-info";
     src = ./.;
   };
-
-  # Specify the GHC version to use.
-  compiler-nix-name = "ghc928";
-
-  # Specify the hackage index state
-  index-state = "2023-11-24T00:00:00Z";
+  inherit (dev) compiler-nix-name index-state;
 }

dev.nix

@@ -0,0 +1,10 @@
+{
+  # Pin haskell-nix to a recent (as of 2023/11/24) commit
+  h8x-commit = "c6e3c91844e91f86cb64015258eed2ed8545d2a9";
+
+  # Specify the GHC version to use.
+  compiler-nix-name = "ghc928";
+
+  # Specify the hackage index state
+  index-state = "2023-11-24T00:00:00Z";
+}

h8x.nix

@@ -1,6 +1,6 @@
 let
-  # Pin haskell-nix to a recent (as of 2023/11/24) commit
-  h8x-commit = "c6e3c91844e91f86cb64015258eed2ed8545d2a9";
+  dev = import ./dev.nix;
+  inherit (dev) h8x-commit;
   h8x-pin = "https://github.com/input-output-hk/haskell.nix/archive/${h8x-commit}.tar.gz";
   h8x-src = builtins.fetchTarball h8x-pin;
   h8x = import h8x-src {};