{ lib, ... }:

with lib;
rec {
  toLua = value: with builtins;
    if value == null then "nil" else
    if isBool value then boolToString value else
    if isInt value || isFloat value then toString value else
    if isString value then string value else
    if isAttrs value then attrs value else
    if isList value then list value else
    abort "should never happen (value = ${value})";

  string = str: ''"${toString str}"'';
  attrs = set:
    let
      toKeyword = name: value: "['${name}'] = ${toLua value}";
      keywords = concatStringsSep ", " (mapAttrsToList toKeyword set);
    in
    "{ " + keywords + " }";

  listContent = values: concatStringsSep ", " (map toLua values);
  list = values: "{ " + listContent values + " }";
}