It seems that you can define "top level" actions and define variables in them. So this would do the trick:
use strict;
use warnings;
use Data::Dumper
use Parse::RecDescent;
### use vars qw/@tokens/; Avoided using global variables
my $p6 = Parse::RecDescent->new(q(
{my @tokens}
letter : /\w/
character : letter
{
push @tokens, $item{letter};
}
Format : character(s) { \@tokens }
));
my $tokens_ref = $p6->Format('abc');
die "Invalid pattern" unless (defined $tokens_ref);
print Dumper $tokens_ref;
Outputs:
$VAR1 = [
'a',
'b',
'c'
];