templates: add Ada template

flake.nix

@@ -167,6 +167,10 @@
         };
       };
 
+      templates."ada" = {
+        path = ./templates/ada;
+        description = "Ada template.";
+      };
       templates."go" = {
         path = ./templates/go;
         description = "Go template.";

templates/ada/.envrc

@@ -0,0 +1 @@
+use flake

templates/ada/flake.nix

@@ -0,0 +1,41 @@
+{
+  description = "thing: stuff and things";
+
+  inputs.nixpkgs.url = "nixpkgs/nixos-22.05";
+
+  outputs = { self, nixpkgs }:
+    let
+      supportedSystems =
+        [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];
+      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;
+      nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+    in {
+      packages = forAllSystems (system:
+        let pkgs = nixpkgsFor.${system};
+        in {
+          thing = pkgs.stdenv.mkDerivation {
+            pname = "thing";
+            version = "v0.0.0";
+            src = ./.;
+          };
+
+          buildPhase = ''
+            gprbuild
+          '';
+        });
+
+      defaultPackage = forAllSystems (system: self.packages.${system}.thing);
+      devShells = forAllSystems (system:
+        let pkgs = nixpkgsFor.${system};
+        in {
+          default = pkgs.mkShell {
+            shellHook = ''
+              PS1='\u@\h:\@; '
+              echo "Ada `${pkgs.gnat12}/bin/gnatmake --version`"
+            '';
+            nativeBuildInputs = with pkgs; [ gnat12 gprbuild ];
+          };
+        });
+    };
+}
+