static S snlToText(S s) {

  ret snlToText(snlToTree(s));

}

static S snlToText(Lisp tree) {

  if (tree == null) ret "";

  tree = snlRemoveReferences(tree);

  if (snlToText_isJuxta(tree))

    tree = snlToText_addDots(tree);

  tree = snlQuestionMarksToBack(tree);

  S snl = snlFromTree(tree);

  new StringBuilder buf;

  L<S> drop = litlist ("[", "]", "<", ">");

  for (S t : codeTokensOnly(snlTok(snl)))

    if (!drop.contains(t)) {

      if (buf.length() != 0 && !litlist(".", "?").contains(t))

        buf.append(" ");

      buf.append(t);

    }

  ret str(buf);

}

static boolean snlToText_isJuxta(Lisp tree) {

  ret eq("*", join(asList(new HashSet<S>(codeTokensOnly(javaTok(tree.head))))));

}

static Lisp snlToText_addDots(Lisp tree) {

  Lisp t = new Lisp(tree.head);

  for (Lisp x : tree) {

    if (x.isA("<") && !x.get(0).is("?", "."))

      x = lisp("<", ".", x);

    t.add(x);

  }

  ret t;

}