gistfile1.txt

class LinesIter is Iterator {
    has $.filehandle;
    has $.value;
    
    method infinite() { False }
    
    method reify() {
        say "errrr?";
        unless $.value.defined {
            my $parcel := pir::new('Parcel');
            my $line = $.filehandle.get;
            say $line;
            if $line.defined {
                pir::push($parcel, $line);
                pir::push($parcel, LinesIter.new(:filehandle($.filehandle)));
            }
            $.value = $parcel;
        }
        $.value;
    }
}

say "got here...";
my $count = 0;
for LinesIter.new(:filehandle($*IN)).list {
    $count++;
}

say :$count.perl;

##########################################################


Wynne:rakudo colomon$ ./perl6 tt4.pl <tenthousand.txt 
got here...
errrr?
Project Gutenberg's Songs of Angus and More Songs of Angus, by Violet Jacob
Cannot modify readonly value
  in '&infix:<=>' at line 1
  in 'LinesIter::reify' at line 17:tt4.pl
  in main program body at line 1