fmt

lib/repl/default.nix

@@ -0,0 +1,58 @@
+# yanked from @fufexan
+{
+  flakePath ? null,
+  hostnamePath ? "/etc/hostname",
+  registryPath ? /etc/nix/registry.json,
+}:
+let
+  inherit (builtins)
+    getFlake
+    head
+    match
+    currentSystem
+    readFile
+    pathExists
+    filter
+    fromJSON
+    ;
+
+  selfFlake =
+    if pathExists registryPath then
+      filter (it: it.from.id == "self") (fromJSON (readFile registryPath)).flakes
+    else
+      [ ];
+
+  flakePath' = toString (
+    if flakePath != null then
+      flakePath
+    else if selfFlake != [ ] then
+      (head selfFlake).to.path
+    else
+      "/etc/nixos"
+  );
+
+  flake = if pathExists flakePath' then getFlake flakePath' else { };
+  hostname =
+    if pathExists hostnamePath then head (match "([a-zA-Z0-9\\-]+)\n" (readFile hostnamePath)) else "";
+
+  nixpkgsFromInputsPath = flake.inputs.nixpkgs.outPath or "";
+  nixpkgs =
+    flake.pkgs.${currentSystem}.nixpkgs
+      or (if nixpkgsFromInputsPath != "" then import nixpkgsFromInputsPath { } else { });
+
+  nixpkgsOutput = removeAttrs (nixpkgs // nixpkgs.lib or { }) [
+    "options"
+    "config"
+  ];
+in
+{
+  inherit flake;
+}
+// flake
+// builtins
+// (flake.nixosConfigurations or { })
+// flake.nixosConfigurations.${hostname} or { }
+// nixpkgsOutput
+// {
+  getFlake = path: getFlake (toString path);
+}