1Clone::PP(3)          User Contributed Perl Documentation         Clone::PP(3)
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NAME

6       Clone::PP - Recursively copy Perl datatypes
7

SYNOPSIS

9         use Clone::PP qw(clone);
10
11         $item = { 'foo' => 'bar', 'move' => [ 'zig', 'zag' ]  };
12         $copy = clone( $item );
13
14         $item = [ 'alpha', 'beta', { 'gamma' => 'vlissides' } ];
15         $copy = clone( $item );
16
17         $item = Foo->new();
18         $copy = clone( $item );
19
20       Or as an object method:
21
22         require Clone::PP;
23         push @Foo::ISA, 'Clone::PP';
24
25         $item = Foo->new();
26         $copy = $item->clone();
27

DESCRIPTION

29       This module provides a general-purpose clone function to make deep
30       copies of Perl data structures. It calls itself recursively to copy
31       nested hash, array, scalar and reference types, including tied
32       variables and objects.
33
34       The clone() function takes a scalar argument to copy. To duplicate
35       arrays or hashes, pass them in by reference:
36
37         my $copy = clone(\@array);    my @copy = @{ clone(\@array) };
38         my $copy = clone(\%hash);     my %copy = %{ clone(\%hash) };
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40       The clone() function also accepts an optional second parameter that can
41       be used to limit the depth of the copy. If you pass a limit of 0, clone
42       will return the same value you supplied; for a limit of 1, a shallow
43       copy is constructed; for a limit of 2, two layers of copying are done,
44       and so on.
45
46         my $shallow_copy = clone( $item, 1 );
47
48       To allow objects to intervene in the way they are copied, the clone()
49       function checks for a couple of optional methods. If an object provides
50       a method named "clone_self", it is called and the result returned
51       without further processing. Alternately, if an object provides a method
52       named "clone_init", it is called on the copied object before it is
53       returned.
54

BUGS

56       Some data types, such as globs, regexes, and code refs, are always
57       copied shallowly.
58
59       References to hash elements are not properly duplicated. (This is why
60       two tests in t/dclone.t that are marked "todo".) For example, the
61       following test should succeed but does not:
62
63         my $hash = { foo => 1 };
64         $hash->{bar} = \{ $hash->{foo} };
65         my $copy = clone( \%hash );
66         $hash->{foo} = 2;
67         $copy->{foo} = 2;
68         ok( $hash->{bar} == $copy->{bar} );
69
70       To report bugs via the CPAN web tracking system, go to
71       "http://rt.cpan.org/NoAuth/Bugs.html?Dist=Clone-PP" or send mail to
72       "Dist=Clone-PP#rt.cpan.org", replacing "#" with "@".
73

SEE ALSO

75       Clone - a baseclass which provides a "clone()" method.
76
77       MooseX::Clone - find-grained cloning for Moose objects.
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79       The "dclone()" function in Storable.
80
81       Data::Clone - polymorphic data cloning (see its documentation for what
82       that means).
83
84       Clone::Any - use whichever of the cloning methods is available.
85

REPOSITORY

87       <https://github.com/neilbowers/Clone-PP>
88

AUTHOR AND CREDITS

90       Developed by Matthew Simon Cavalletto at Evolution Softworks.  More
91       free Perl software is available at "www.evoscript.org".
92

94       Copyright 2003 Matthew Simon Cavalletto. You may contact the author
95       directly at "evo@cpan.org" or "simonm@cavalletto.org".
96
97       Code initially derived from Ref.pm. Portions Copyright 1994 David Muir
98       Sharnoff.
99
100       Interface based by Clone by Ray Finch with contributions from
101       chocolateboy.  Portions Copyright 2001 Ray Finch. Portions Copyright
102       2001 chocolateboy.
103
104       You may use, modify, and distribute this software under the same terms
105       as Perl.
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109perl v5.34.0                      2021-07-22                      Clone::PP(3)
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