Questions about statement modifiers

[Agent Zhang]

Hi, there~

I think S04 says too little about statement modifiers. Please comment
on the following code samples. Are they valid Perl 6?

   do { say } for 1..3;

   { say } for 1..3;

   -> $i { say $i } for 1..3;

And how about similar variations for other statement modifiers, such
as  while, given, if, until, and unless?

Thanks!

Agent