// split smth like "if * then *" into "if *" and "then *"

// returns null if no split

// now also for NL trees

static L<Lisp> snlSplitOps(Lisp code) {

  new L<Lisp> out;

  if (code.is("[]")) {

    // NL

    if ((code.size() & 1) != 0) ret null;

    for (int i = 0; i < code.size(); i += 2) {

      Lisp op = code.get(i), arg = code.get(i+1);

      if (!op.isLeaf() || !isExtendedIdentifier(op.head)) ret null;

      out.add(lisp(op + " *", nlUnbracket(arg)));

    }

    ret out;

  }

  S ops = code.head;

  L<S> tok = codeTokensOnly(javaTok(ops));

  if ((l(tok) & 1) != 0) ret null;

  for (int i = 0; i < l(tok); i += 2) {

    S op = tok.get(i);

    if (!isIdentifier(op) || neq("*", tok.get(i+1))) ret null;

    out.add(lisp(op + " *", code.get(i/2)));

  }

  //print("splitOps => " + structure(out));

  ret out;

}