use Parse::RecDescent;

#$RD_TRACE=1;
#$RD_HINT=1;

my $parser = Parse::RecDescent->new(<<'EOG') or die;

    list1N_c:    term(s /,/)
    list1N_s:    term(s /\/+/)

    list0N_c:    term(s? /,/)
    list0N_s:    term(s? /\/+/)

    list01_c:    term(? /,/)
    list01_s:    term(? /\/+/)

    list2_c:    term(2 /,/)
    list2_s:    term(2 /\/+/)

    list02_c:    term(0..2 /,/)
    list02_s:    term(0..2 /\/+/)

    list2N_c:    term(2.. /,/)
    list2N_s:    term(2.. /\/+/)

    list13_c:    term(..3 /,/)
    list13_s:    term(..3 /\/+/)

    term: 't'
EOG

while (<DATA>)
{
    print;
    print "\tlist1N_c:\t", @{$parser->list1N_c($_)||['undef']}, "\n";
    print "\tlist1N_s:\t", @{$parser->list1N_s($_)||['undef']}, "\n";

    print "\tlist0N_c:\t", @{$parser->list0N_c($_)||['undef']}, "\n";
    print "\tlist0N_s:\t", @{$parser->list0N_s($_)||['undef']}, "\n";

    print "\tlist01_c:\t", @{$parser->list01_c($_)||['undef']}, "\n";
    print "\tlist01_s:\t", @{$parser->list01_s($_)||['undef']}, "\n";

    print "\tlist2_c:\t", @{$parser->list2_c($_)||['undef']}, "\n";
    print "\tlist2_s:\t", @{$parser->list2_s($_)||['undef']}, "\n";

    print "\tlist02_c:\t", @{$parser->list02_c($_)||['undef']}, "\n";
    print "\tlist02_s:\t", @{$parser->list02_s($_)||['undef']}, "\n";

    print "\tlist2N_c:\t", @{$parser->list2N_c($_)||['undef']}, "\n";
    print "\tlist2N_s:\t", @{$parser->list2N_s($_)||['undef']}, "\n";

    print "\tlist13_c:\t", @{$parser->list13_c($_)||['undef']}, "\n";
    print "\tlist13_s:\t", @{$parser->list13_s($_)||['undef']}, "\n";

    print "-----\n";
}

__DATA__

t
t,t
t,t,t
t,t,t,t
t
t/t
t/t//t
t/t///t/t