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