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Programming-Idioms

  • Pascal
  • Perl

Idiom #311 Deep copy an object

Create the new object y by cloning the all the contents of x, recursively.

use v5.7.3;
use Storable qw(dclone);
my $x = [ 1, 2, [ 'a' ], { x => [3,4] } ];

my $y = dclone $x;

The core module Storable (available since v5.7.3) provides a dclone function that will deeply copy any object or arbitrarily complex structure such as list of lists or hashes.
classes
var
  x,y: TPersistent;
...
  y.assign(x);
...
let y = structuredClone(x);
New implementation...
< > ⌨
programming-idioms.org 
my $x = [ 1, 2, [ 'a' ], { x => [3,4] } ];

my $y = dclone $x;
var
  x,y: TPersistent;
...
  y.assign(x);
...
let y = structuredClone(x);
y = copy.deepcopy(x)
y = Marshal.load(Marshal.dump(x))