Section: User Contributed Perl Documentation (3)
Tie::Cycle - Cycle through a list of values via a scalar.
tie my $cycle, 'Tie::Cycle', [ qw( FFFFFF 000000 FFFF00 ) ];
say $cycle; # FFFFFF
say $cycle; # 000000
say $cycle; # FFFF00
say $cycle; # FFFFFF back to the beginning
(tied $cycle)->reset; # back to the beginning
You use "Tie::Cycle"
to go through a list over and over again.
Once you get to the end of the list, you go back to the beginning.
You don't have to worry about any of this since the magic of
tie does that for you.
The tie takes an array reference as its third argument. The tie
should succeed unless the argument is not an array reference.
Previous versions required you to use an array that had more
than one element (what's the pointing of looping otherwise?),
but I've removed that restriction since the number of elements
you want to use may change depending on the situation.
During the tie, this module makes a shallow copy of the array
reference. If the array reference contains references, and those
references are changed after the tie, the elements of the cycle
will change as well. See the included test.pl script for an
example of this effect.
You can call methods on the underlying object (which you access
Roll the iterator back to the starting position. The next access
will give the first element in the list.
Give the previous element. This does not affect the current position.
Give the next element. This does not affect the current position.
You can peek at the next element if you like.
This module is on Github:
brian d foy, "<email@example.com>"
COPYRIGHT AND LICENSE
Copyright © 2000-2017, brian d foy "<firstname.lastname@example.org>"
. All rights reserved.
This software is available under the Artistic License 2.0.