with import ./lib.nix;

let

  attrs =
    {
      y = "y";
      x = "x";
      foo = "foo";
    }
    // rec {
      x = "newx";
      bar = x;
    };

  names = builtins.attrNames attrs;

  values = map (name: builtins.getAttr name attrs) names;

in
assert values == builtins.attrValues attrs;
concat values