Restructure everything

flake.nix

@@ -1,28 +1,43 @@
 {
-  description = "The Sieve of Eratosthenes implemented in many different languages";
+  description = "Templates of the Sieve of Eratosthenes implemented in various languages";
 
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs";
-    flake-utils.url = "github:numtide/flake-utils";
-  };
+  outputs = { self, ... }:
+    let
+      # Get all project directories
+      subdirs = dir:
+        let sub = builtins.readDir dir;
+        in builtins.filter
+          (d: sub.${d} == "directory")
+          (builtins.attrNames sub);
 
-  outputs = { self, nixpkgs, flake-utils, ... }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = nixpkgs.legacyPackages.${system};
-        inherit (pkgs) lib;
+      vowelStart = str: builtins.elem (builtins.substring 0 1 str) [ "a" "e" "i" "o" "u" ];
 
-        # Check if project has a shell.nix
-        hasShell = dir: builtins.pathExists ./${dir}/shell.nix;
+      concatMapAttrs = func: attr:
+        builtins.foldl' (x: y: x // y) {}
+          (builtins.map func attr);
 
-        # Get all project directories
-        currentDir = builtins.readDir ./.;
-        dirs = builtins.attrNames (lib.filterAttrs (_: v: v == "directory") currentDir);
-      in
-        builtins.foldl' lib.recursiveUpdate {} (builtins.map (dir: {
-          packages.${dir} = pkgs.callPackage ./${dir} {};
-        } // lib.optionalAttrs (hasShell dir) {
-          devShells.${dir} = pkgs.callPackage ./${dir}/shell.nix {};
-        }) dirs)
-    );
+      templateDirs =
+        builtins.concatMap (lang:
+          builtins.map
+            (pkg: { inherit lang pkg; })
+            (subdirs ./${lang}))
+          (subdirs ./.);
+    in {
+      templates = concatMapAttrs ({ lang, pkg }: {
+        "${lang}-${pkg}" = {
+          description = "Packaging a${if vowelStart lang
+                                      then "n"
+                                      else ""} ${lang} executable using ${pkg}";
+          path = builtins.filterSource
+            (path: type: builtins.baseNameOf path != "flake.lock")
+            ./${lang}/${pkg};
+        };
+      }) templateDirs // concatMapAttrs (lang: {
+        "${lang}" = self.templates."${lang}-nixpkgs" // {
+          description = "Packaging a${if vowelStart lang
+                                      then "n"
+                                      else ""} ${lang} executable";
+        };
+      }) (subdirs ./.);
+    };
 }