NAME

       Array::Iterator::BiDirectional - A subclass of Array::Iterator to allow forwards and backwards iteration

VERSION

       This document describes version 0.131 of Array::Iterator::BiDirectional (from Perl distribution Array-
       Iterator), released on 2021-09-26.

SYNOPSIS

         use Array::Iterator::BiDirectional;

         # create an instance of the iterator
         my $i = Array::Iterator::BiDirectional->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

       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.

HOMEPAGE

       Please visit the project's homepage at <https://metacpan.org/release/Array-Iterator>.

SOURCE

       Source repository is at <https://github.com/perlancar/perl-Array-Iterator>.

SEE ALSO

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

AUTHOR

       perlancar <perlancar@cpan.org>

ORIGINAL AUTHOR

       stevan little, <stevan@iinteractive.com>

CONTRIBUTING

       To contribute, you can send patches by email/via RT, or send pull requests on GitHub.

       Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then
       test via:

        % prove -l

       If you want to build the distribution (e.g. to try to install it locally on your system), you can install
       Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, and sometimes one or two other Dist::Zilla
       plugin and/or Pod::Weaver::Plugin. Any additional steps required beyond that are considered a bug and can
       be reported to me.

COPYRIGHT AND LICENSE

       This software is copyright (c) 2021, 2017, 2013, 2012, 2011 by perlancar <perlancar@cpan.org>.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5
       programming language system itself.

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.

BUGS

       Please report any bugs or feature requests on the bugtracker website
       <https://rt.cpan.org/Public/Dist/Display.html?Name=Array-Iterator>

       When submitting a bug or request, please include a test-file or a patch to an existing test-file that
       illustrates the bug or desired feature.