Updated: MapCar was a bad choice. This one is actually pretty cool: 
use Algorithm::Loops 'NestedLoops';

my $iter = NestedLoops([\@arr, do {my $i=0; sub {[$i++]}} ]);

while (my ($line, $x) = &$iter) {
    print "$x: $line\n";
}

[download]
Obviously, modifying $line isn't going to affect @arr, though. To do that, you'd have to do 
use Algorithm::Loops 'NestedLoops';

my $iter = NestedLoops([[\(@arr)], do {my $i=0; sub {[$i++]}} ]);

while (my ($line, $x) = &$iter) {
    for my $line ($$line) {
        print "$x: $line\n";
        $line = 'X';
    }
}

print "@arr\n";

[download]
Caution: Contents may have been coded under pressure.

In reply to Re: Foreach Loops by Roy Johnson
in thread Foreach Loops by hubb0r

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