Class TypesForSets

collectiontopics/TypesForSets.java:39–74

}

public class TypesForSets {
  static <T> void
  fill(Set<T> set, Function<Integer, T> type) {
    for(int i = 10; i >= 5; i--) // Descending
      set.add(type.apply(i));
    for(int i = 0; i < 5; i++) // Ascending
      set.add(type.apply(i));
  }
  static <T> void
  test(Set<T> set, Function<Integer, T> type) {
    fill(set, type);
    fill(set, type); // Try to add duplicates
    fill(set, type);
    System.out.println(set);
  }
  public static void main(String[] args) {
    test(new HashSet<>(), HashType::new);
    test(new LinkedHashSet<>(), HashType::new);
    test(new TreeSet<>(), TreeType::new);
    // Things that don't work:
    test(new HashSet<>(), SetType::new);
    test(new HashSet<>(), TreeType::new);
    test(new LinkedHashSet<>(), SetType::new);
    test(new LinkedHashSet<>(), TreeType::new);
    try {
      test(new TreeSet<>(), SetType::new);
    } catch(Exception e) {
      System.out.println(e.getMessage());
    }
    try {
      test(new TreeSet<>(), HashType::new);
    } catch(Exception e) {
      System.out.println(e.getMessage());
    }
  }
}
/* Output:
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
[10, 9, 8, 7, 6, 5, 0, 1, 2, 3, 4]