sub ranger {
    my @arr = @{$_[0]};
    my ($r1, $r2) = @{$_[1]};
    my ($sr1, $sr2) = @{$_[2]};

    my @v = eval <<__END_EVAL__;
\$[ = $r1;
($sr1 < $sr2)
    ? \@arr[ $sr1 .. $sr2 ]
    : reverse \@arr[ $sr2 .. $sr1 ];
__END_EVAL__
    return @v;
}