static S javaDropAllComments(S s) {
  ret join(javaDropAllComments(javaTok(s)));
}

static LS javaDropAllComments(LS tok) {
  for (int i = 0; i < l(tok); i += 2)
    tok.set(i, tok_javaDropCommentsFromWhitespace(tok.get(i)));
  ret tok;
}