static S textOut_and(Collection<S> l) {
  ret textOut_and(l, "nothing");
}

static S textOut_and(Collection<S> l, S emptyText) {
  if (empty(l)) ret emptyText;
  L<S> separators = rep(", ", l(l)-2);
  separators.add(" and ");
  ret join_flex(separators, l);
}