Clone::PP - Recursively copy Perl datatypes
use Clone::PP qw(clone);
$item = { 'foo' => 'bar', 'move' => [ 'zig', 'zag' ] };
$copy = clone( $item );
$item = [ 'alpha', 'beta', { 'gamma' => 'vlissides' } ];
$copy = clone( $item );
$item = Foo->new();
$copy = clone( $item );
Or as an object method:
require Clone::PP;
push @Foo::ISA, 'Clone::PP';
$item = Foo->new();
$copy = $item->clone();
This module provides a general-purpose clone function to make deep copies of
Perl data structures. It calls itself recursively to copy nested hash, array,
scalar and reference types, including tied variables and objects.
The
clone() function takes a scalar argument to copy. To duplicate arrays
or hashes, pass them in by reference:
my $copy = clone(\@array); my @copy = @{ clone(\@array) };
my $copy = clone(\%hash); my %copy = %{ clone(\%hash) };
The
clone() function also accepts an optional second parameter that can
be used to limit the depth of the copy. If you pass a limit of 0, clone will
return the same value you supplied; for a limit of 1, a shallow copy is
constructed; for a limit of 2, two layers of copying are done, and so on.
my $shallow_copy = clone( $item, 1 );
To allow objects to intervene in the way they are copied, the
clone()
function checks for a couple of optional methods. If an object provides a
method named "clone_self", it is called and the result returned
without further processing. Alternately, if an object provides a method named
"clone_init", it is called on the copied object before it is
returned.
Some data types, such as globs, regexes, and code refs, are always copied
shallowly.
References to hash elements are not properly duplicated. (This is why two tests
in t/dclone.t that are marked "todo".) For example, the following
test should succeed but does not:
my $hash = { foo => 1 };
$hash->{bar} = \{ $hash->{foo} };
my $copy = clone( \%hash );
$hash->{foo} = 2;
$copy->{foo} = 2;
ok( $hash->{bar} == $copy->{bar} );
To report bugs via the CPAN web tracking system, go to
"
http://rt.cpan.org/NoAuth/Bugs.html?Dist=Clone-PP" or send mail to
"Dist=Clone-PP#rt.cpan.org", replacing "#" with
"@".
Clone - a baseclass which provides a "clone()" method.
MooseX::Clone - find-grained cloning for Moose objects.
The "dclone()" function in Storable.
Data::Clone - polymorphic data cloning (see its documentation for what that
means).
Clone::Any - use whichever of the cloning methods is available.
<
https://github.com/neilbowers/Clone-PP>
Developed by Matthew Simon Cavalletto at Evolution Softworks. More free Perl
software is available at "
www.evoscript.org".
Copyright 2003 Matthew Simon Cavalletto. You may contact the author directly at
"
[email protected]" or "
[email protected]".
Code initially derived from Ref.pm. Portions Copyright 1994 David Muir Sharnoff.
Interface based by Clone by Ray Finch with contributions from chocolateboy.
Portions Copyright 2001 Ray Finch. Portions Copyright 2001 chocolateboy.
You may use, modify, and distribute this software under the same terms as
Perl.