Overloading won't be necessary. You can tie an array to your Foo::Bar object by defining the methods Foo::Bar::TIEARRAY(), Foo::Bar::FETCH, Foo::Bar::STORE(), etc. They will all look like ordinary instance methods except TIEARRAY(), which looks like a class constructor method.

It's not difficult to write methods which tie an array to an array reference. The methods' arguments can be found in perltie. For example,

# args: self, index, value
sub STORE {
    my ($self, $index, $value) = @_;
    $self->[$index] = $value;
}
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The tied operator returns the tied object, so you can call the Foo::Bar::baz() method on your array by,

tied(@array)->baz();
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Looks a little weird, but, doesn't this solve your problem?

use strict;
use warnings;
package Foo::Bar;

sub new {
        tie my @arr, 'Foo::Bar';
        return bless \@arr, 'Foo::Bar';
}

sub lalala {
    my $self = shift;
    print "Lalala\n";
}

sub TIEARRAY {
    return bless [], 'Foo::Bar';
}

sub FETCH {
    print "Fetch\n";
    my ($self, $index) = @_;
    return $self->[$index];
}

sub STORE {
    print "Store\n";
    my ($self, $index, $value) = @_;
    return $self->[$index] = $value;
}

package main;

my $a = Foo::Bar->new();
$a->lalala();
$a->[0] = 1;
print $a->[0];
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I'm afraid I still don't quite understand the relationship between \@arr in the constructor and the [] array ref in TIEARRAY. Would you mind rewriting this example in a way that demonstrates the "two-faced" aspect of what I'm trying to achieve? There is something like it in perltie, but it doesn't actually have an additional 'new' constructor to abstract away the tie'ing (and uses a hash) and I couldn't quite rework it in the way I intend.

Thanks so much!

Ok, Here goes a more complex example, wich shows it in more details:

use strict;
use warnings;
package Foo::Bar;

sub new {
        tie my @arr, 'Foo::Bar';
        return bless \@arr, 'Foo::Bar';
}

sub TIEARRAY {
    my $scalar = "A Scalar";
    return bless \$scalar, 'Foo::Bar';
}

sub FETCH {
    my ($self, $index) = @_;
    print 'FETCH ';
    if ($index == 0) {
        return $self->lalala0;
    } elsif ($index == 1) {
        return $self->lalala1;
    } else {
        return undef;
    }
}

sub STORE {
    my ($self, $index, $value) = @_;
    print 'STORE ';
    if ($index == 0) {
        return $self->lalala0($value);
    } elsif ($index == 1) {
        return $self->lalala1($value);
    } else {
        return undef;
    }
}

sub lalala {
    my $self = shift; 
    if (UNIVERSAL::isa($self,'ARRAY')) { $self = tied(@{$self}) };
    print "Lalala $self\n";
}

sub lalala0 {
    my $self = shift; 
    if (UNIVERSAL::isa($self,'ARRAY')) { $self = tied(@{$self}) };
    print "Lalala0 $self\n";
}

sub lalala1 {
    my $self = shift; 
    if (UNIVERSAL::isa($self,'ARRAY')) { $self = tied(@{$self}) };
    print "Lalala1 $self\n";
}

sub DESTROY {
    my $self = shift;
    if (UNIVERSAL::isa($self,'ARRAY')) {
        print "Destroying the array...\n";
    } else {
        print "Destroying the scalar...\n";
    }
}

package main;

my $a = Foo::Bar->new();
# The object inside is a SCALAR
$a->lalala();
$a->[0] = $a->[1];
$a->[1] = $a->[0];
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UPDATE: Included the DESTROY method, to illustrate...

daniel

Thank you both for your replies. Unfortunately, they don't completely address my question. The big idea was that the objects themselves would still be scalar references (not array references), except they would behave as array references. In the perltie perldoc there is an example that does this with a hash reference, so I think it must be possible.

In the original class constructor a UID is generated. The object is a reference to this UID (hence a scalar). I like to keep this (but have the objects behave as array references).

You still have tied($arr_ref) to get your scalar reference

daniel

package Foo::Bar;
use strict;
use warnings;

my @aoa;
my $cnt;
sub new { bless \(my $obj_index = $cnt++) }
sub DESTROY { undef $aoa[${$_[0]}] }
use overload '@{}' => sub { $aoa[${$_[0]}] ||= [] }, fallback => 1;
1;
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