let
  scan = import ./scan.nix;

  flake' = self: { imports, exports , base }@schema: { ... }@inputs: { ... }@imports: let
    lib = {
      inherit scan schema inputs imports;
      extend = flake schema inputs imports;
      new = flake {} {} {};
      # TODO: override
    };
    convert = attr: value: value self inputs imports;

    result = (builtins.mapAttrs convert schema.exports);
  in result // { lib = lib // (result.lib or {}); };

  flake =  { imports?{}, exports?{}, base?[] }@schema'old: { ... }@inputs'old: { ... }@imports'old: { ... }@inputs'new: base: let
    schema = {
      imports = (schema'old.imports or {}) // scan { base = base + "/import"; recursive = true; };
      exports = (schema'old.exports or {}) // scan { base = base + "/export"; };
      base = [ base ] ++ (schema'old.base or []);
    };

    merge = attr: let
      old = imports'old.${attr} or {};
      new = imports'new.${attr} or {};
    in builtins.mapAttrs (attr: _: (old.${attr} or []) ++ (new.${attr} or [])) (old//new);

    imports'new = builtins.mapAttrs (name: value: scan { base = base + "/${name}"; convert = name: content: [ (value name content) ]; }) schema.imports;
    result = flake' result schema
      (inputs'old // (builtins.removeAttrs inputs'new ["self"]))
      (builtins.mapAttrs (attr: _: merge attr) schema.imports);
  in result;

in flake {} {} {}