NAME

Data::Comparable - Present your object for comparison purposes

VERSION

version 1.100840

SYNOPSIS

use base 'Data::Comparable';

      sub prepare_comparable {
          my $self = shift;
          $self->SUPER::prepare_comparable(@);
          delete $self->{sometemp_value};
          $self->items;    # autovivify;
      }

      # in some test file:

      use Test::Differences;
      my $x = '...';
      my $y = '...';
      eq_or_diff($x->comparable, $y->comparable, 'objects are equal');

DESCRIPTION

When you define a class, it may not be so straightforward to compare two objects of that class. For example, you want to compare object $x to object $y. You would like to use "is_deeply()" from Test::More, but it complains that some hash keys are undef in one object but completely missing in the other. That is easily solved by autovivifying the keys in question. Also, some hash keys might be irrelevant to comparison - that is, you still consider two objects to be equal even though they differ in some hash keys.

This is where Data::Comparable can help. It enables you to define how your object wants to look like when it is being passed to some deep comparison function like "Test::More::is_deeply()" or "Test::Differences::eq_or_diff()". If your class inherits from Data::Comparable, it gets a method called "comparable()", which you can call when comparing it. That is, you don't compare the actual objects, but their comparable versions.

To define the comparable version of your object, your class has to implement the "prepare_comparable()" method. There you can autovivify any hash keys you like or tweak your object in any way you need to make it comparable.

METHODS
comparable
FIXME

comparable_scalar
FIXME

dump_comparable
FIXME

prepare_comparable
FIXME

yaml_dump_comparable
FIXME

INSTALLATION

See perlmodinstall for information and options on installing Perl modules.

BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests through the web interface at <http://rt.cpan.org/Public/Dist/Display.html?Name=Data-Comparable>.

AVAILABILITY

The latest version of this module is available from the Comprehensive Perl Archive Network (CPAN). Visit <http://www.perl.com/CPAN/> to find a CPAN site near you, or see
<http://search.cpan.org/dist/Data-Comparable/>.

The development version lives at
<http://github.com/hanekomu/Data-Comparable/>. Instead of sending patches, please fork this project using the standard git and github infrastructure.

AUTHOR

Marcel Gruenauer <marcel@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2004 by Marcel Gruenauer.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.