[TxMt] Perl language definition: switch, case?

I'm just updating the Perl language definition to support the new keywords and operators in 5.10. I notice that keyword.control.perl includes 'switch' and 'case' (which aren't Perl keywords; it's given/ when in 5.10) and also 'select' which is a function rather than a control keyword.

Is there a compelling reason not to remove switch, case and move select to the functions list?

Also, because I'm a TM language definition newbie, does anyone have any tips about how to handle the // (defined or) operator? In some contexts // is an empty regex; in others it's an operator

my @x = split //, $line; # regex, common idiom to chop into chars my $x = $y // $z; # operator, equiv: my $x = defined $y ? $y : $z