Yet another way, using List::MoreUtils:

use List::MoreUtils qw( natatime );

$_ = '0 X X X X X X X X 1 X X X X X X X X 2 X X X X X X X X 3 X X X X 
+X X X X 4 X X X X X X X X 5 X X X X X X X X 6 X X X X X X X X 7';
my @a = split;
my $it = natatime(8,@a);
while (my @v = $it->())
{
    print "@v\n";
}
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Converting that into an appropriately parameterized function is an exercise left for... you. ;-)