NAME

Array::Circular - Provide an array data structure that can go around in circles.

DESCRIPTION

Circular array, tracks how many times it's been round.

SYNOPSIS

    my $a = Array::Circular->new(qw/once upon a time there was/);
    my $current = $l->next;
    say "They are the same" if $current == $l->current;
    my $first = $l->previous;
    say "Also the same" if $first == $l->current;
    say "We went around the loop " . $l->loops . " times";

METHODS

new

    my $a = Array::Circular->new(qw/this is a test/);

next

    my $element     = $l->next;
    my $two_forward = $l->next(2);

previous / prev

    my $element = $l->previous;
    my $two_back = $l->previous(2);

current / curr

    my $element = $l->current;

index

    my $idx = $l->index;
    $idx    = $l->index(3);

Gets or sets the current index. Always returns the value of the current index. Does not reset the loop counter. No validation is performed.

loops

    my $number_of_times_been_around = $l->loops
    $l->loops(-3);

The loops method keeps track of how many times the array has been around. Looping forwards increases the loop count. Looping back decreases it. Sending in a number will set the counter but beware, no validation is performed on set operations.

reset

    $l->reset

Resets the current index and loop count to 0.

me

    my $internal_store = $l->me

This is the internal store that tracks the current state of the list. It's intended for internal use only.

current_and_next / curr_and_next

Convenience method to return current value then proceed next. Same interface as next.

current_and_previous / curr_and_prev

Convenience method to return current value then proceed previous. Same interface as previous.

peek

Peek n forward (defaults to 1). Take care if you're reliant on calculating the number of loops as part of this. This Returns the entry for each without updating the value of loops.

size

Returns the number of elements in the list.

GOTCHAS

Some array modification operations are supported. For example splice, push and pop operations are untested. If you mutate the array you may consider using reset, loops and index to fix up the effects of your mutation.

IMPLEMENTATION NOTES

This module is implemented as an inside out object.

SEE ALSO

Array::Iterator::Circular provides similar functionality but it does not support previous. Array::Iterator contains a survey of various similar modules.

TODO

Not thread safe. See implementation of Hash::MultiValue for implementation of thread safety. Alternatively use Hash::Util::FieldHash or Hash::Util::FieldHash::Compat.

AUTHOR COPYRIGHT AND LICENSE

Copyright 2018 Kieren Diment zarquon@cpan.org. This software can be redistributed under the same terms as perl itself.

cpanm Array::Circular

perl -MCPAN -e shell
install Array::Circular