flake.nix instead of shell.nix

README.md

@@ -549,11 +549,11 @@ for various parts of the library.
 
 ### Nix
 
-The file `shell.nix` declares a *Nix* shell environment which provides all
+The file `flake.nix` declares a *Nix* shell development environment which provides all
 dependencies for every target in the `Makefile`, including *Doxygen*.
 Enter the *Nix* shell by
 [installing *Nix*](https://nixos.org/download.html)
-and then running `nix-shell` in this directory. From the `nix-shell` prompt,
+and then running `nix develop` in this directory. From the `nix develop` prompt,
 you will be able to build all `Makefile` targets.
 
 ### Pull Requests

flake.nix

@@ -0,0 +1,27 @@
+{
+  description = "hffix";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, ... }@inputs:
+    inputs.flake-utils.lib.eachDefaultSystem (system:
+    let
+      pkgs = import nixpkgs { inherit system; };
+    in
+    {
+        devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ doxygen stack gmp zlib ];
+          buildInputs = with pkgs; [ boost ];
+          LC_ALL = "C.UTF-8";
+          shellHook = ''
+            echo ""
+            echo '  hffix Development Environment'
+            echo '  To run the test suite: make test'
+            echo ""
+          '';
+        };
+    });
+}