// DrJava saved history v2
import java.util.*;
Stack s = new Stack();
s.push("foo");
(Entry)s.pop();
Entry e = (Entry) s.pop();
s.push("foo");
Entry e1 = (Entry) s.peek();
e1;
e1.getName();
e1 = (Entry) s.peek();
Entry e2;
e2 = (Entry) s.peek();
List daniel = new Empty();
List alan = new Empty();
List cathy = new Empty();
List voltaire = new Cons("xyz", alan);
List daniel = new Empty();
List cathy = new Empty();
List cathy = new Empty();
List daniel = Empty.ONLY;
List cathy = Empty.ONLY;
cathy = Empty.ONLY;
List alan = Empty.ONLY;
cathy == alan;
List jeannie = Empty.ONLY;
List mary = new Cons("abc", jeannie);
mary;
mary.toString();
List jeannie = Empty.ONLY;
List mary = new Cons("abc", jeannie);
List carolyn = new Cons(new Integer(5), mary);
List carmar = carolyn.concat(mary);
carmar = carolyn.concat(mary);
carmar;
carmar.getFirst();
((Cons)carmar).getFirst();
Cons cm2 = (Cons)((Cons)carmar).getRest();
cm2.getFirst();
throw new RuntimeException("This is an exception!");
import java.util.*;
throw new NoSuchElementException("There is no last element of an empty list");
import java.util.NoSuchElementException;
import java.util.NoSuchElementException;
throw new NoSuchElementException("Attempt to take last element of empty list");
throw new NoSuchElementException("Attempt to take last element of empty list");
// Hint on writing last() in OO style: use a helper method called returnArgIfEmpty(Object o);
Integer i1 = new Integer(5);
Integer i2 = new Integer(12);
i1.compareTo(i2);
i2.compareTo(i1);
i2.compareTo(i2);
Object o1 = "A";
Object o2 = "B";
o2.compareTo(o2);
((Comparable)o1).compareTo(o2);
Comparable o1c = (Comparable) o1;
o1c.compareTo(o2);
o1c.compareTo(new Integer(5));
Alan = new Surgeon();
Alan.operate("Zung");
Alan = new Surgeon();
Betty = new SnakeDoctor();
Alan.operate("Dr. J");
Betty.operate("Zung");
List alan = Empty.ONLY;
List helen = new Cons(new Integer(5), alan);
alan = Empty.ONLY;
helen = new Cons(new Integer(5), alan);
helen;
cathy = new Cons(new Integer(-13), helen);
cathy.getFirst().compareTo(new Integer(7));
((Comparable)cathy.getFirst()).compareTo(new Integer(7));
Comparable f = (Comparable)cathy.getFirst();
f = (Comparable)cathy.getFirst();
f;
f.compareTo(new Integer(-20));
// do something like this:
if (f.compareTo(new Integer(-20) == 1) return f; else return new Integer(-20);