NAME

Data::Compare - compare perl data structures

SYNOPSIS

    use Data::Compare;

    my $h = { 'foo' => [ 'bar', 'baz' ], 'FOO' => [ 'one', 'two' ] };
    my @a1 = ('one', 'two');
    my @a2 = ('bar', 'baz');
    my %v = ( 'FOO', \@a1, 'foo', \@a2 );

    # simple procedural interface
    print 'structures of $h and \%v are ',
      Compare($h, \%v) ? "" : "not ", "identical.\n";

    # OO usage
    my $c = new Data::Compare($h, \%v);
    print 'structures of $h and \%v are ',
      $c->Cmp ? "" : "not ", "identical.\n";
    # or
    my $c = new Data::Compare;
    print 'structures of $h and \%v are ',
      $c->Cmp($h, \%v) ? "" : "not ", "identical.\n";

DESCRIPTION

Compare two perl data structures recursively. Returns 0 if the structures differ, else returns 1.

A few data types are treated as special cases:

Scalar::Properties objects

This has been moved into a plugin, although functionality remains the same as with the previous version. Full documentation is in Data::Compare::Plugins::Scalar-Properties.

Compiled regular expressions, eg qr/foo/

These are stringified before comparison, so the following will match:

    $r = qr/abc/i;
    $s = qr/abc/i;
    Compare($r, $s);

and the following won't, despite them matching *exactly* the same text:

    $r = qr/abc/i;
    $s = qr/[aA][bB][cC]/;
    Compare($r, $s);

Sorry, that's the best we can do.

CODE and GLOB references

These are assumed not to match unless the references are identical - ie, both are references to the same thing.

PLUGINS

The module takes plug-ins so you can provide specialised routines for comparing your own objects and data-types. For details see Data::Compare::Plugins.

A couple of functions are provided to examine what goodies have been made available through plugins:

plugins

Returns a structure (a hash ref) describing all the comparisons made available through plugins. This function is *not* exported, so should be called as Data::Compare::plugins(). It takes no parameters.

plugins_printable

Returns formatted text

BUGS

Plugin support is not quite finished (see the TODO file for details) but is usable. The missing bits are bells and whistles rather than core functionality.

AUTHOR

Fabien Tassin fta@sofaraway.org

Copyright (c) 1999-2001 Fabien Tassin. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Seeing that Fabien seems to have disappeared, David Cantrell has become a co-maintainer so he can apply needed patches. The licence, of course, remains the same, and all communications about this module should be CCed to Fabien in case he ever returns and wants his baby back.

Portions, including plugins, copyright 2003-2004 David Cantrell david@cantrell.org.uk

SEE ALSO

perl(1), perlref(1)