Scalar::Cycle::Manual - Cycle through a list of values (with optional automatic incrementation)
use Scalar::Cycle::Manual ; my $cyclic_variable = new 'Scalar::Cycle::Manual', qw( first second third ) ; print $cyclic_variable; # 'first' print $cyclic_variable; # still 'first' print $cyclic_variable->next ; # 'second' print $cyclic_variable; # still 'first' print $cyclic_variable->previous; # 'third' print $cyclic_variable; # still 'first' print $cyclic_variable->increment; print $cyclic_variable; # 'second' print $cyclic_variable->increment; print $cyclic_variable; # 'third' $cyclic_variable->reset; print $cyclic_variable; # first print $cyclic_variable->decrement; print $cyclic_variable; # 'third' $cyclic_variable++; print $cyclic_variable; # 'first' $cyclic_variable--; print $cyclic_variable; # 'third' $cyclic_variable->auto_increment(1) ; print $cyclic_variable; # 'third' print $cyclic_variable; # 'first'
There's a bunch of modules implementing a scalar which cycles in a list of values. Take your time to compare them.
If you want more control over when the variable cycles, this module may suit your needs.
Use Scalar::Cycle::Manual to go through a list over and over again. Once you get to the end of the list, you go back to the beginning.
Scalar::Cycle::Manual
These operator act as the increment and decrement subroutines.
These operators implement the fetching of the current value in scalar and string context.
The '<>' operator returns the current value and increments the current position even if auto_increment is set to 0.
Creates a Scalar::Cycle::Manual object that you can use to cycle through values.
use Scalar::Cycle::Manual ; my $cyclic_variable = new 'Scalar::Cycle::Manual'( qw( first second third )) ;
Arguments
@value_list - list of values to be cycled through
Return
a Scalar::Cycle::Manual object
This is needed by the ++ operator.
When set, the current position in the value list is automatically incremented after the value is accessed.
When a Scalar::Cycle::Manual object is created, auto_increment is set to false.
my $cyclic_variable = new 'Scalar::Cycle::Manual'( qw( first second third )) ; print $cyclic_variable; # 'first' print $cyclic_variable; # 'first' $cyclic_variable->auto_increment(1) ; print $cyclic_variable; # 'second' print $cyclic_variable; # 'third' my $is_auto_increment_on = $cyclic_variable->auto_increment() ;
$boolean- an optional value to set the auto_increment state
If $bolean is not defined, the current state is returned
Transform the object to the current cycle values. This is automatically called by Perl.
use Scalar::Cycle::Manual ; my $cyclic_variable = new 'Scalar::Cycle::Manual'( qw( first second third )) ; my $value = $cyclic_variable ; print $cyclic_variable ;
the current value extracted from the cycle values.
Forces the Scalar::Cycle::Manual to change to the next value in the cycle value list.
use Scalar::Cycle::Manual ; my $cyclic_variable = new 'Scalar::Cycle::Manual'( qw( first second third )) ; print $cyclic_variable->increment; print $cyclic_variable ; # or print $cyclic_variable->increment;
the next value, extracted from the cycle values.
Forces the Scalar::Cycle::Manual to change to the previous value in the value list.
print $cyclic_variable->previous; print $cyclic_variable ; # or print $cyclic_variable->previous;
the previous value, extracted from the cycle values.
Makes the current value the first value in the value list.
use Scalar::Cycle::Manual ; my $cyclic_variable = new 'Scalar::Cycle::Manual'( qw( first second third )) ; $cyclic_variable->auto_increment(1) ; print $cyclic_variable; # 'first' $cyclic_variable->reset ; print $cyclic_variable; # 'first'
Returns the value prior to the value at the current position. This does not affect the current position in the cycle value list.
the value prior to the value at the current position
Returns the value next to the value at the current position. This does not affect the current position in the value list.
the value next to the value at the current position
None so far.
Khemir Nadim ibn Hamouda CPAN ID: NKH mailto:nadim@khemir.net
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
You can find documentation for this module with the perldoc command.
perldoc Scalar::Cycle::Manual
You can also look for information at:
AnnoCPAN: Annotated CPAN documentation
http://annocpan.org/dist/Scalar-Cycle-Manual
RT: CPAN's request tracker
Please report any bugs or feature requests to L <bug-Scalar-cycle-manual@rt.cpan.org>.
We will be notified, and then you'll automatically be notified of progress on your bug as we make changes.
Search CPAN
http://search.cpan.org/dist/Scalar-Cycle-Manual
Scalar-MultiValue
by Graciliano Monteiro Passos: Create a SCALAR with multiple values.
List-Rotation
by Imre Saling: Loop (Cycle, Alternate or Toggle) through a list of values via a singleton object implemented as closure.
Tie::FlipFlop
by Abigail: Alternate between two values.
List::Cycle
by Andi Lester: Objects for cycling through a list of values
Tie::Cycle
by Brian D. Foy: Cycle through a list of values via a scalar.
Tie::Toggle
by Brian D. Foy: False and true, alternately, ad infinitum.
To install Scalar::Cycle::Manual, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Scalar::Cycle::Manual
CPAN shell
perl -MCPAN -e shell install Scalar::Cycle::Manual
For more information on module installation, please visit the detailed CPAN module installation guide.