Provided by: libarray-iterator-perl_0.11-2_all
NAME
Array::Iterator::BiDirectional - A subclass of Array::Iterator to allow forwards and backwards iteration
VERSION
version 0.11
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.
BUGS
None that I am aware of, if you find a bug, let me know, and I will be sure to fix it.
CODE COVERAGE
See the CODE COVERAGE section of the Array::Iterator documentation for information about the code coverage of this module's test suite.
SEE ALSO
This is a subclass of Array::Iterator, please refer to it for more documenation.
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.
AUTHOR
Steven Haryanto <stevenharyanto@gmail.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by Steven Haryanto. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.