BOOLEAN out_metadata "Output metadata in YAML format?" STEERABLE=always
{
} no

  yaml << YAML::EndSeq;
  yaml << YAML::EndMap;
  return yaml;
}
YAML::Emitter &operator<<(YAML::Emitter &yaml, const amrex::FabArrayBase &fab) {
  yaml << YAML::LocalTag("fabarraybase-1.0.0");
  yaml << YAML::BeginMap;
  yaml << YAML::Key << "ixType" << YAML::Value << YAML::Flow << YAML::BeginSeq;
  const auto ixtype = fab.ixType();
  for (int d = 0; d < dim; ++d)
    yaml << ixtype[d];
  yaml << YAML::EndSeq;
  yaml << YAML::Key << "nGrowVect" << YAML::Value << YAML::Flow
       << YAML::BeginSeq;
  const auto ngrowvect = fab.nGrowVect();
  for (int d = 0; d < dim; ++d)
    yaml << ngrowvect[d];

  yaml << YAML::Key << "boxArray" << YAML::Value << YAML::BeginSeq;
  for (int n = 0; n < fab.size(); ++n) {
    yaml << YAML::Flow << YAML::BeginMap;
    yaml << YAML::Key << "small" << YAML::Value << YAML::Flow << YAML::BeginSeq;
    for (int d = 0; d < dim; ++d)
      yaml << fab.boxArray()[n].smallEnd(d);
    yaml << YAML::EndSeq;
    yaml << YAML::Key << "big" << YAML::Value << YAML::Flow << YAML::BeginSeq;
    for (int d = 0; d < dim; ++d)
      yaml << fab.boxArray()[n].bigEnd(d);
    yaml << YAML::EndSeq;
    yaml << YAML::EndMap;
  }
  yaml << YAML::EndSeq;

  yaml << YAML::Key << "fab" << YAML::Value << /*TODO*/ "fab";

  yaml << YAML::Key << "fab" << YAML::Value << *leveldata.fab;

struct parameters {};
YAML::Emitter &operator<<(YAML::Emitter &yaml, parameters) {
  yaml << YAML::LocalTag("parameters-1.0.0");
  yaml << YAML::BeginMap;
  int first = 1;
  for (;;) {
    const cParamData *data;
    // This call is most likely not thread safe
    int ierr = CCTK_ParameterWalk(first, nullptr, nullptr, &data);
    assert(ierr >= 0);
    if (ierr)
      break;
    const string fullname = string(data->thorn) + "::" + data->name;
    yaml << YAML::Key << fullname << YAML::Value << YAML::Flow;
    int type;
    const void *pvalue = CCTK_ParameterGet(data->name, data->thorn, &type);
    switch (type) {
    case PARAMETER_KEYWORD:
    case PARAMETER_STRING:
      yaml << *static_cast<const char *const *>(pvalue);
      break;
    case PARAMETER_INT:
      yaml << *static_cast<const CCTK_INT *>(pvalue);
      break;
    case PARAMETER_REAL:
      yaml << *static_cast<const CCTK_REAL *>(pvalue);
      break;
    case PARAMETER_BOOLEAN:
      yaml << static_cast<bool>(*static_cast<const CCTK_INT *>(pvalue));
      break;
    default:
      assert(0);
    }
    first = 0;
  }
  yaml << YAML::EndMap;
  return yaml;
}

  if (!out_metadata)
    return;

  // yaml << YAML::Key << "iteration";
  // yaml << YAML::Value << cctk_iteration;
  // yaml << YAML::Key << "time";
  // yaml << YAML::Value << cctk_time;

  yaml << YAML::Key << "nghostzones";
  yaml << YAML::Value << YAML::Flow << YAML::BeginSeq;
  for (int d = 0; d < dim; ++d)
    yaml << cctk_nghostzones[d];
  yaml << YAML::EndSeq;
  yaml << YAML::Key << "origin_space";
  yaml << YAML::Value << YAML::Flow << YAML::BeginSeq;
  for (int d = 0; d < dim; ++d)
    yaml << cctk_origin_space[d];
  yaml << YAML::EndSeq;
  yaml << YAML::Key << "delta_space";
  yaml << YAML::Value << YAML::Flow << YAML::BeginSeq;
  for (int d = 0; d < dim; ++d)
    yaml << cctk_delta_space[d];
  yaml << YAML::EndSeq;
  yaml << YAML::Key << "iteration";
  yaml << YAML::Value << cctk_iteration;
  yaml << YAML::Key << "time";
  yaml << YAML::Value << cctk_time;
  yaml << YAML::Key << "delta_time";
  yaml << YAML::Value << cctk_delta_time;

  yaml << YAML::Key << "parameters";
  yaml << YAML::Value << parameters();