#
# This software is Copyright 2005 by Elsevier Inc.  You may use it
# under the terms of the license at http://perl.plover.com/hop/LICENSE.txt .
#



###
### chronologically-orcish
###

## Chapter 3 section 10

{ my %cache;
  sub chronologically {
    ($cache{$a} ||= date_to_string($a))
       cmp
    ($cache{$b} ||= date_to_string($b))
  }
}