You almost got me. :)

On page 103, TheDamian explains that calling a 'constructor' as an object method is a lazy way to copy an object, but observe what happens when you change an object's attributes at runtime and try to clone it:

use strict;
use Clone qw(clone);

my $foo = foo->new();
$foo->{spam} = {spam =>'eggs'};

my $bad_clone  = $foo->new();
my $good_clone = clone($foo);

$bad_clone->{spam}->{spam}  or warn "bad has no eggs";
$good_clone->{spam}->{spam} or warn "good has no eggs";

package foo;
use strict;

sub new {
   my $class = shift;
   my $proto = ref($class) || $class;
   return bless {}, $proto;
}
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TheDamian also explains on page 105 that

While many experts view the overloading of constructors as object copiers to be a natural extension of their functionality, others consider the technique unintuitive, too subtle, and more likely to produce obscure and hard-to-maintain code.

and on page 106

If you have a choice, it's probably better to code a seperate clone method. Apart from keeping your individual methods simpler and less prone to bugs, the method's name will force client code to be more clearly self-documenting.

jeffa

doesn't like spam

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