{ base, convert ? name: value: value, recursive ? false }:
let
  scan = sub: let
    all = builtins.readDir (base + "/${builtins.concatStringsSep "/" sub}");
    names = filter: builtins.filter filter (builtins.attrNames all);
    nix = name: all.${name} == "regular" && builtins.stringLength name > 4 && builtins.substring (builtins.stringLength name - 4) 4 name == ".nix";
    dir = name: all.${name} == "directory";
    files = map (name: sub ++ [ (builtins.substring 0 (builtins.stringLength name - 4) name) ]) (names nix);
    dirs = builtins.concatLists (map (name: scan (sub ++ [name])) (names dir));
  in if recursive then files ++ dirs else files;

  root = scan [];

  item = relative: let
    name = builtins.concatStringsSep "/" relative;
    absolute = base + "/${name}.nix";
    content = import absolute;
    value = convert name content;
  in { inherit name value; };

  items = map item root;

in if builtins.pathExists base then builtins.listToAttrs (map item root) else {}