[eru]

> Yes, you can guarantee that a linked list in Java is finite because Java does not support codata.

What about another thread running that keeps generating pieces to the end of the linked list? (No problem, with mutation.)

[cousin_it]

To prevent these and similar "what abouts", here's an implementation of a guaranteed finite linked list in Java.

    class LinkedList<T> {
      public final T value;
      public final LinkedList<T> next;
      public LinkedList(T value, LinkedList<T> next) {
        this.value = value;
        this.next = next;
      }
    }

Here's how you construct it:

    LinkedList<String> myList =
      new LinkedList("Hello",
        new LinkedList("World", null));

Here's how you iterate over it in constant space:

    while (myList != null) {
      System.out.println(myList.value);
      myList = myList.next;
    }