I am dealing with a data format that has a Pascal string representation like element to it. i.e. an integer followed a number of elements indicated by the leading integer. I'd like to encapsulate this within a Parse::RecDescent grammar using some of the magic from dynamically matched rules together with subrule repetition, but can't get it to work. Any recommendations? Code is below.

#!/usr/bin/perl

use strict;
use warnings;
use Test::More tests => 5;
use Parse::RecDescent;

my $p=Parse::RecDescent->new(q{
rec:  int   elem("$item[1]")
int:  /\d+/
elem: /\S+/
});
ok($p->rec('0'));
ok($p->rec('1 foo'));
ok($p->rec('2 foo bar'));
ok(!$p->rec('1'));
ok(!$p->rec('1 foo bar'));
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For now I am using the equivalent of:

rec:  int   elem(s?)
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but that doesn't provide the check I want (i.e. the 4th and 5th tests fail) and is slower than I think it would be if I could specify the exact number of items to match.

Thanks, Les