Array::Iterator::LegacyBiDirectional(3)

VERSION
Version 0.136

SYNOPSIS
  use Array::Iterator::LegacyBiDirectional;

  # create an instance of the iterator
  my $i = Array::Iterator::LegacyBiDirectional->new(1 .. 100);

  while ($some_condition_exists) {
      # get the latest item from
      # the iterator
      my $current = $i->get_next();
      # ...
      if ($something_happens) {
          # back up the iterator
          $current = $i->get_previous();
      }
  }

DESCRIPTION
This is the old BiDirectional code. It is kept for users who want the old way that the pointer was kept. See RT#126034 for further details.

Occasionally it is useful for an iterator to go in both directions, forward and backward. One example would be token processing. When looping though tokens it is sometimes necessary to advance forward looking for a match to a rule. If the match fails, a bi-directional iterator can be moved back so that the next rule can be tried.

METHODS
This is a subclass of Array::Iterator, only those methods that have been added are documented here, refer to the Array::Iterator documentation for more information.

has_previous([$n])
    This method works much like "hasNext" does, it will return true (1) unless the beginning of the array has been reached, and false (0) otherwise.

    Optional argument has the same meaning except that it specifies $nth previous element.

previous
    This method is much like "next". It will return the previous item in the iterator, and throw an exception if it attempts to reach past the beginning of the array.

get_previous
    This method is much like "get_next". It will return the previous item in the iterator, and return undef if it attempts to reach past the beginning of the array.

look_back([$n])
    This is the counterpart to "peek", it will return the previous items in the iterator, but will not affect the internal counter.

    Optional argument has the same meaning except that it specifies $nth previous element.

SEE ALSO
This is a subclass of Array::Iterator, please refer to it for more documentation.

MAINTAINER
Nigel Horne, "<njh at nigelhorne.com>"

2025-2026

ORIGINAL AUTHOR
stevan little, <stevan@iinteractive.com>

ORIGINAL COPYRIGHT AND LICENSE
Copyright 2004 by Infinity Interactive, Inc.

<http://www.iinteractive.com>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.