#
# 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 .
#



###
### append_optimized
###

## Chapter 4 section 6.3.1

sub append {
  my @its = @_;
  return Iterator {
    until (@its == 0 || defined my $val = NEXTVAL($its[0])) {
      shift @its;
    }
    return if @its == 0;
    return $val;
  }
}