you're right that it's expensive. but the grep method is even slower, because the arrays are ~30000 long, and the information i "extract" from them is somewhere near the beginning of the array and their length is somewhere between 1-15. the grep method iterates to the end of the array which is what i try to prevent

my first version just splice'd it the amount of $#cvs_to_delete, it ran quick, but i can't be sure it works.

i'll try to make something that splices all consequtive rows in one sweep.

here's the code i ended up for splicing subsequent indexes in one go. i have to say it saves me literally hours.

# now we'll pop away what we found from the AoH
# basically we splice out subsequent indexes in one go
# and the poor lonelies have to go home alone
# if nothing is to be popped, we don't pop
unless (scalar @i_to_delete) {
    return $text;
}

@i_to_delete = sort {$b <=> $a} @i_to_delete; # descending order
my $length = 1;
my $offset = undef;
for my $i (0 .. $#i_to_delete) {
    if ($i < $#i_to_delete) { # not the last index
        if (($i_to_delete[$i] - $i_to_delete[$i+1]) == 1) { # the two 
+are subsequent
            $length++;
        } else { # they are not subsequent, split current
            $offset = $i_to_delete[$i];
            splice(@$AoH, $offset, $length);
            $length = 1;
        }
    } else { # last index
        $offset = $i_to_delete[$i];
        splice(@$AoH, $offset, $length);
        $length = 1;
    }
}
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