1 // Copyright (c) 2008 Per M.A. Bothner.
2 // This is free software;  for terms and warranty disclaimer see ./COPYING.
3 
4 package gnu.lists;
5 import java.io.*;
6 
7 public class ImmutablePair extends Pair
8 {
ImmutablePair(Object carval, Object cdrval)9   public ImmutablePair (Object carval, Object cdrval)
10   {
11     super(carval, cdrval);
12   }
13 
ImmutablePair()14   public ImmutablePair ()
15   {
16   }
17 
setCar(Object car)18   public void setCar (Object car)
19   {
20     throw new UnsupportedOperationException("cannot modify read-only pair");
21   }
22 
setCdr(Object cdr)23   public void setCdr (Object cdr)
24   {
25     throw new UnsupportedOperationException("cannot modify read-only pair");
26   }
27 }
28