sub mapn (&$@) {
    my( $code, $n, ) = ( shift, shift );
    map {
        $code->( @_[ $_ .. $_ + $n -1 ] );
    } map $n * $_, 0 ..  ( $#_ / $n );
}

my $s = join',', 1 .. 11;
my( @odds, @evens );

mapn{ 
    push @odds,  shift||(); 
    push @evens, shift||();
} 2, split ',', $s;

print "@odds\n@evens";;
1 3 5 7 9 11
2 4 6 8 10