Your algorythm is very fast. Congratulations! I tried to come up with something close in speed to what you have, but I could not. Instead I will submit my attempt in the hopes that it might spawn off an idea for someone else:

sub dkubb_LUHN10 {
  my $number = shift;
  my $sum;
  ($sum += chop $number) ... ($sum += $LUHN10_map[chop $number]) 
    while $number ne '';
  ($sum % 10 == 0) || 0;
}

[download]

Update: The last line was: $sum % 10 || 0;

In reply to (dkubb) Re: (2) YAL10CI (Yet Another LUHN-10 Checksum Implementation) by dkubb
in thread YAL10CI (Yet Another LUHN-10 Checksum Implementation) by larryl

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