http://qs321.pair.com?node_id=388356


in reply to Finding missing numbers in a list

Set::IntSpan offers some nice features: 
use Set::IntSpan;

my $set = Set::IntSpan->new("41888, 41889, 41890, 41892, 41895");
$set = $set->complement()->intersect(
    Set::IntSpan->new($set->min . "-" . $set->max));
print $set->run_list(), "\n";

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prints out 
41891,41893-41894

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