How do I match a newline or the end of a file in a Raku grammar?

Question

I have run into headaches trying to coerce a grammar to match the last line of a file if it is not followed by a newline:

Line 1
Line 2 EOF

This attempted solution, which makes the newline optional, causes an infinite loop:

my grammar HC4 {
    token TOP {  <line>+ }
    token line { [ <header> | <not-header> ] \n? } # optional newline

    token header { <header-start> <header-content> }
    token not-header { <not-header-content> }
    token header-start { \s* '#' ** 1..6 }
    token header-content { \N* }
    token not-header-content { \N* }
}

The \N* bits will match the '' string after the last character in the last line forever.

I have tried using <[\n\Z]> but then the compiler complains and suggests using \n?$ which I tried but that does not work either. After a lot of trial and error, the only solution I discovered that works requires me to create a new <blank> capture and to change the \N* to \N+:

my grammar HC3 {
    token TOP {  <line>+ }
    token line { [ <header> | <blank> | <not-header> ] \n? }

    token header { <header-start> <header-content> }
    token blank { \h* <?[\n]> }
    token not-header { <not-header-content> }
    token header-start { \s* '#' ** 1..6 }
    token header-content { \N+ }
    token not-header-content { \N+ }
}

I'd like to know if there is a more straightforward accomplishing this, though. Thanks.

Answer 1

I think I may have found something that can work and is simple:

my grammar G {
    token TOP {  (^^ <line>)+ }
    token line { \N* \n? }
}

The ^^ symbol, for the beginning of a line, stops the infinite loop.