Solution: make your hashes objects of a class that implements that behaviour. Ah, you are already on that path. I see $self in your code. But how are %hash and $self supposed to be related?

package myHash;

sub new { bless {}, shift }

sub AUTOLOAD {
    # next two lines just to see what's happening...
    print '@_ = ('.join(', ',map{"'$_'"}@_), ")\n";
    print "\$AUTOLOAD = $AUTOLOAD\n";

    my ($self,$value) = @_;
    (my $key = $AUTOLOAD) =~ s/.*:://;
    $self->{$key} = $value if $value;
    $self->{$key};
} 
1;
[download]

Now you can

#!/usr/bin/perl
use myHash;
$thingy = myHash->new(foo => 'bar');
print $thingy->foo,"\n";
print $thingy->foo('baz'),"\n";
print $thingy->age('ageless'),"\n";
__END__
#output:
@_ = ('myHash=HASH(0x8166c28)')
$AUTOLOAD = myHash::foo

@_ = ('myHash=HASH(0x8166c28)', 'baz')
$AUTOLOAD = myHash::foo
baz
@_ = ('myHash=HASH(0x8166c28)', 'ageless')
$AUTOLOAD = myHash::age
ageless
@_ = ('myHash=HASH(0x8166c28)')
$AUTOLOAD = myHash::DESTROY
[download]

Note the last two lines - since our myHash package doesn't have a method called DESTROY, the AUTOLOAD routine is called to handle DESTROY during global destruction (at program's end). See perlobj.

But you don't have to roll your own, There are some modules at CPAN which implement autogeneration of accessors, getters/setters (for instance, Class::Accessor, Class::MethodMaker, ...), then there's Spiffy which provides some other nifty features.

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}