package StupidAutoloader;

use strict;
use warnings;

use Carp;

our %Classes;

sub import {
    my $class = shift;
    my @hierarchies = @_;
    %Classes = map {($_, undef)} @hierarchies;
    *UNIVERSAL::new = sub {
        my $proto = $_[0];
        my $class = ref($proto) || $proto;

        croak "Could not find method new() in package '$class'."
          if ref($proto) or
             exists $INC{$class} or
             not in_hierarchy(\%Classes, $class);
        
        eval "use $class;";
        croak "Error loading module '$class': $@" if $@;
        no strict 'refs';
        goto &{"${class}::new"};
    };
}

sub in_hierarchy {
    my $h = shift;
    my $c = shift;
    return 1 if exists $h->{$c};

    my @levels = split /::/, $c;
    my $accum;
    foreach (@levels) {
        $accum .= $_;
        return 1 if exists $h->{"${accum}::*"}
    }
    return 0;
}

1;
[download]

#!/usr/bin/perl
use strict;
use warnings;

use StupidAutoloader 'Data::*';

my $d = Data::Dumper->new([]);
print "$d\n";
my $g = Data::Grouper->new(a => []);
print "$g\n";
[download]