static LS mapLike splitTokens(O splitter, LS tok) {
  new LS out;
  LS l;
  for i over tok:
    if (odd(i) && l(l = (LS) callF(splitter, tok.get(i))) > 1) {
      for j over l: {
        if (j > 0) out.add("");
        out.add(l.get(j));
      }
    } else
      out.add(tok.get(i));
  ret out;
}

Began life as a copy of #1022420