File: //usr/local/ssl/local/share/man/man3/List::Cycle.3
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.\" ========================================================================
.\"
.IX Title "Cycle 3"
.TH Cycle 3 "2010-04-16" "perl v5.8.8" "User Contributed Perl Documentation"
.SH "NAME"
List::Cycle \- Objects for cycling through a list of values
.SH "VERSION"
.IX Header "VERSION"
Version 1.00
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
List::Cycle gives you an iterator object for cycling through a series
of values. The canonical use is for cycling through a list of colors
for alternating bands of color on a report.
.PP
.Vb 1
\& use List::Cycle;
.Ve
.PP
.Vb 7
\& my $colors = List::Cycle->new( {values => ['#000000', '#FAFAFA', '#BADDAD']} );
\& print $colors->next; # #000000
\& print $colors->next; # #FAFAFA
\& print $colors->next; # #BADDAD
\& print $colors->next; # #000000
\& print $colors->next; # #FAFAFA
\& ... etc ...
.Ve
.PP
You'd call it at the top of a loop:
.PP
.Vb 5
\& while ( ... ) {
\& my $color = $colors->next;
\& print qq{<tr bgcolor="$color">;
\& ...
\& }
.Ve
.PP
Note that a List::Cycle object is not a standard Perl blessed hash.
It's an inside-out object, as suggested in \fIPerl Best Practices\fR.
In the five years since \fI\s-1PBP\s0\fR has come out, inside-out objects have
been almost universally ignored, but I keep List::Cycle as an example.
If you don't care about the internals of the object, then List::Cycle
is a fine module for you to use.
.SH "FUNCTIONS"
.IX Header "FUNCTIONS"
.Sh "new( {values => \e@values} )"
.IX Subsection "new( {values => @values} )"
Creates a new cycle object, using \fI@values\fR.
.PP
The \f(CW\*(C`values\*(C'\fR keyword can be \f(CW\*(C`vals\*(C'\fR, if you like.
.ie n .Sh """$cycle\->set_values(\e@values)"""
.el .Sh "\f(CW$cycle\->set_values(\e@values)\fP"
.IX Subsection "$cycle->set_values(@values)"
Sets the cycle values and resets the internal pointer.
.Sh "$cycle\->reset"
.IX Subsection "$cycle->reset"
Sets the internal pointer back to the beginning of the cycle.
.PP
.Vb 5
\& my $color = List::Cycle->new( {values => [qw(red white blue)]} );
\& print $color->next; # red
\& print $color->next; # white
\& $color->reset;
\& print $color->next; # red, not blue
.Ve
.Sh "$cycle\->dump"
.IX Subsection "$cycle->dump"
Returns a handy string representation of internals.
.Sh "$cycle\->next"
.IX Subsection "$cycle->next"
Gives the next value in the sequence.
.SH "AUTHOR"
.IX Header "AUTHOR"
Andy Lester, \f(CW\*(C`<andy at petdance.com>\*(C'\fR
.SH "SUPPORT"
.IX Header "SUPPORT"
You can find documentation for this module with the perldoc command.
.PP
.Vb 1
\& perldoc List::Cycle
.Ve
.PP
You can also look for information at:
.IP "* AnnoCPAN: Annotated \s-1CPAN\s0 documentation" 4
.IX Item "AnnoCPAN: Annotated CPAN documentation"
<http://annocpan.org/dist/List\-Cycle>
.IP "* \s-1CPAN\s0 Ratings" 4
.IX Item "CPAN Ratings"
<http://cpanratings.perl.org/d/List\-Cycle>
.IP "* \s-1RT:\s0 \s-1CPAN\s0's request tracker" 4
.IX Item "RT: CPAN's request tracker"
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=List\-Cycle>
.IP "* Search \s-1CPAN\s0" 4
.IX Item "Search CPAN"
<http://search.cpan.org/dist/List\-Cycle>
.IP "* Source code repository" 4
.IX Item "Source code repository"
<http://github.com/petdance/list\-cycle>
.SH "BUGS"
.IX Header "BUGS"
Please report any bugs or feature requests to
\&\f(CW\*(C`bug\-list\-cycle @ rt.cpan.org\*(C'\fR, or through the web interface at
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=List\-Cycle>.
I will be notified, and then you'll automatically be notified of progress on
your bug as I make changes.
.SH "ACKNOWLEDGEMENTS"
.IX Header "ACKNOWLEDGEMENTS"
List::Cycle is a playground that uses some of the ideas in Damian Conway's
marvelous \fIPerl Best Practices\fR. <http://www.oreilly.com/catalog/perlbp/>
One of the chapters mentions a mythical List::Cycle module, so I made
it real.
.PP
Thanks also to Ricardo \s-1SIGNES\s0 and Todd Rinaldo for patches.
.SH "COPYRIGHT & LICENSE"
.IX Header "COPYRIGHT & LICENSE"
Copyright 2005\-2010 Andy Lester.
.PP
This program is free software; you can redistribute it and/or modify it
under the terms of either:
.IP "* the \s-1GNU\s0 General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version, or" 4
.IX Item "the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version, or"
.PD 0
.IP "* the Artistic License version 2.0." 4
.IX Item "the Artistic License version 2.0."
.PD
.PP
1; # End of List::Cycle