1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
|
import org.checkerframework.checker.nullness.qual.*;
class Node {
int id;
@Nullable Node next;
Node(int id, @Nullable Node next) {
this.id = id;
this.next = next;
}
}
class SubEnumerate {
protected @Nullable Node current;
public SubEnumerate(Node node) {
this.current = node;
}
@EnsuresNonNullIf(expression = "current", result = true)
public boolean hasMoreElements() {
return (current != null);
}
}
class Enumerate extends SubEnumerate {
public Enumerate(Node node) {
super(node);
}
public boolean hasMoreElements() {
return (current != null);
}
}
class Main {
public static final void main(String args[]) {
Node n2 = new Node(2, null);
Node n1 = new Node(1, n2);
Enumerate e = new Enumerate(n1);
while (e.hasMoreElements()) {}
}
}
|
