!752

p {
  for (S s : litlist("1 2 3", "1, 2, 3", "1,_2,_44", "_1 _2", "1,", ",1"))
    print(quote(s) + " => " + structure(splitIDs(s)));
}

static L<S> splitIDs(S s) {
  ret asList(s.split("[ ,]+"));
}