package Games::Dice;

use warnings;
use strict;
use vars '$AUTOLOAD';

sub AUTOLOAD {
  if ( $AUTOLOAD =~ /^.*::(\d+)[Dd](\d+)/ ) {
    buildsub($AUTOLOAD,$1,$2);
    goto &$AUTOLOAD;
  }
}

sub buildsub {
    my ($name,$rolls,$die) = @_;
    my $sub = <<END_SUB;
sub $name {
  my \$result = $rolls;
  for( my \$i = 0; \$i < $rolls; \$i++ ) {
    \$result += int(rand($die));
  }
  return \$result;
}
END_SUB
    eval $sub;
    die "Oops, dropped a die" if ($@);
}

sub import {
  no strict 'refs';
  my $pkg = shift;
  my $caller = caller(0);
  for my $dice (@_) {
    if ($dice =~ /(\d+)[Dd](\d+)/) {
      buildsub("$pkg\::$dice",$1,$2);
      *{"$caller\::$dice"} = \&{"$pkg\::$dice"};
    }
  }
}
1;

# Example use
package main;
use Games::Dice ( '3d6' );

my %rolls;
for (1..1000) {
  my $roll = main::3d6; # The main:: is required because???
  $rolls{$roll}++;
}

for (sort {$a<=>$b} keys %rolls) {
  print "$_ => $rolls{$_}\n";
}