Split works at run time, but it could, in principle, evaluate at compile time when it has a constant argument. For example, the ord() Perl function is evaluate

Split works at run time, but it could, in principle, evaluate at compile time when it has a constant argument. For example, the ord() Perl function is evaluated at compile time if the argument is a constant string. (It's not worth it because split() syntax isn't as clean as qw() for this purpose. split's first arg, if present, is the pattern to split on.)