Perl6 object cloning test

gistfile1.6pl

#!/usr/bin/env perl6

use v6;

class obj {
    has $.attr is rw  = 42;
    has @.shallow = 1,2,3;
    has @.deep = [1,2,3],[4,5,6];
}

my $a = obj.new;
my $b = $a.clone;
my $c = $a;

say $a.perl;
say $b.perl;
say $c.perl;

$a.deep[1][0]="a";
$a.shallow[0]="a";

say $a.perl;
say $b.perl;
say $c.perl;

$b.deep[1][1]="b"; # changes a
$b.shallow[1]="b"; # changes a

say $a.perl;
say $b.perl;
say $c.perl;

$c.deep[1][2]="c"; # changes a
$c.shallow[2]="c"; # changes a

say $a.perl;
say $b.perl;
say $c.perl;

$c.attr=44; # changes a
$b.attr=43; # changes ONLY b

say $a.perl;
say $b.perl;
say $c.perl;

copying($a);

immutable($a);

sub copying (obj $d is copy) {
    $d.attr=0;
    $d.shallow[0]='d';
    $d.deep[1][0]='d';
    say "in sub copying";
    say $a.perl;
    say $b.perl;
    say $c.perl;
    say $d.perl;
}

sub immutable (obj $e) {
    use Test;
    $e.attr=1;
    $e.shallow[0]='e';
    $e.deep[1][0]='e';
    say "in sub immutable";
    say $a.perl;
    say $b.perl;
    say $c.perl;
    say $e.perl;
}

say "cloning using .clone and passing attribs in";
my $f = $a.clone(deep => ( [7,8,9],[10,11,12] ) );
say "f: " ~ $f.perl;
$f.deep[0][0]=1001;
say "a: " ~ $a.perl;
say "f: " ~ $f.perl;

say "cloning using .clone and attrs from a";
my $g = $f.clone(deep => $a.deep );
say "g: " ~ $g.perl;
$g.deep[0][0]=42;
say "g: " ~ $g.perl;
say "a: " ~ $a.perl;
say "f: " ~ $f.perl;

say "cloning using .clone and attrs from a";
my $h = $f.clone(deep => $a.deep.clone );
say "h: " ~ $h.perl;
$h.deep[0][0]=43;
say "h: " ~ $h.perl;
say "a: " ~ $a.perl;
say "f: " ~ $f.perl;