@Test
public void testLexicon() {

  List<String> ops = Arrays.asList(
      "++", "--", "+", "-", "+=", "-=", "+++",
      "=", "==", "===", "!", "!=", "<", "<=", ">", ">=", "<>");
  Lexicon lexicon = Operators.lexicon(ops);
  for (String op : ops) {
    assertEquals(Tokens.reserved(op), lexicon.word(op));
  }
  for (String op : ops) {
    assertEquals(Tokens.reserved(op), lexicon.tokenizer.parse(op));
  }
}