I am trying to write a function that makes use of a cache. The problem is that the data in the cache should be initialized as it is used. However, the cache holds onto the raw form, and subsiquent accesses require the data to be initialized again.

Is there a way to make this work? 
#!/usr/bin/perl -w

use diagnostics;
use strict;

{
    my $cache = [Foo->new];
    sub access_cache {
        return @$cache;
    }
}

foreach (&access_cache()) {
    print "before: ", ref($_), "\n";
    print "object: ", $_, "\n";
    print "after:  ", ref($_), "\n";
    print "\n";
}

foreach (&access_cache()) {
    print "before: ", ref($_), "\n";
    print "object: ", $_, "\n";
    print "after:  ", ref($_), "\n";
    print "\n";
}

package Foo;
sub new {bless [], $_[0]};
use overload '""' => sub {$_[0] = Bar->new; return $_[0]->[0]};

package Bar;
sub new {bless ['barbar'], $_[0]};
use overload '""' => sub {return $_[0]->[0]};

[download]
The output of this program is: 
before: Foo
object: barbar
after:  Bar

before: Foo
object: barbar
after:  Bar

[download]
I am trying to get it so that the output will look like this instead: 
before: Foo
object: barbar
after:  Bar

before: Bar
object: barbar
after:  Bar

[download]
I am using This is perl, version 5.005_03 built for i386-freebsd.

I would greatly appreciate any assistance that is offered.

In reply to Implementing a Data Cache by zealot

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