well, i do not feel very comfortable with grammars yet - you'll note this when my explanations start to get wacky ;) (to be honest, i hope i get some upvotes for formatting reasons ...)

the rule 'ip' nicely encloses a key=value pair, the same sort of rule can be applied to the mask. further, the name 'ip' is IMO not very well chosen, i rename it to 'ip_def'. finally, break the first regexp into its pieces, so you can specify whitespaces. the first rule gets:

network_object: 'network' ':' /(\w+)/ '=' '{' ip_def mask_def host(s) 
+'}'

[download]

your problem with hosts_or_range is that you want to do too much within one rule. at first, it is irrelevant if a host has one ip or a whole range. so you can pull 'host:' one level up.

host        : 'host' ':' /\w+/ '=' '{' ip_or_range '}'

[download]

if a host has an ip, it starts with the string 'ip'. if a host has an associated ip range, it starts with 'range' - and your problem disappears

ip_or_range : 'ip' '=' ip ';'
            | 'range' '=' ip '-' ip ';'

[download]

in your grammar, the rule 'hosts_or_range' tries to do two jobs:

the whole thing gets (plus added return values): 
my $grammar = <<'GRAMMAR';
parse: network_object(s)
network_object: 'network' ':' /(\w+)/ '=' '{' ip_def mask_def host(s) 
+'}'
    { $return = {
        NETWORK => $item[3],
        SUBNET => $item[6],
        NETMASK => $item[7],
        HOSTS => $item[8],
    }; }

mask_def    : 'mask' '=' ip ';'
    { $return = $item[3]; }

ip_def      :     'ip' '=' ip ';'
    { $return = $item[3]; }

host        : 'host' ':' /\w+/ '=' '{' ip_or_range '}'
    { $return = [$item[3], $item[6]]; }

ip_or_range : 'ip' '=' ip ';' { $return = $item[3]; }
            | 'range' '=' ip '-' ip ';'
    { $return = {RANGE_START => $item[3], RANGE_END => $item[5]}; }

ip          : /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/
    { $return = $item[1]; }
GRAMMAR

[download]

fed with your example, this eventually returns:

$VAR1 = [
          {
            'NETMASK' => '255.255.255.0',
            'HOSTS' => [
                         [
                           'asterix',
                           '10.1.1.10'
                         ],
                         [
                           'obelix',
                           '10.1.1.11'
                         ],
                         [
                           'idefix',
                           '10.1.1.12'
                         ],
                         [
                           'ix_13_20',
                           {
                             'RANGE_START' => '10.1.1.13',
                             'RANGE_END' => '10.1.1.20'
                           }
                         ]
                       ],
            'NETWORK' => 'north',
            'SUBNET' => '10.1.1.0'
          }
        ];

[download]
HTH

In reply to Re: Parse::RecDescent and <score: ...> directive by kabel
in thread Parse::RecDescent and <score: ...> directive by orrence

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