#!/usr/bin/env perl
use warnings;
use strict;

use Data::Dumper;
use Marpa::R2;

my $rules = <<'END_OF_GRAMMAR';
    lexeme default  = latm => 1
    
	:default        ::= action => [values]
    <entry>         ::= <op> (SP) <hostaddr4> 
    <op>            ::= 'add' | 'remove'
    
    <ipv4>          ::= NUMBER ('.') NUMBER ('.') NUMBER ('.') NUMBER
    <hostname>      ::= NAME
    
    <hostaddr4>     ::= <ipv4> | <hostname> 
    
    SP              ~ [\s]+    
    NAME            ~ [\S]+
    NUMBER          ~ [\d]+
END_OF_GRAMMAR

my $input = <<'END_OF_INPUT';
add 192.0.2.1
add www.example.org
remove 192.0.2.2
END_OF_INPUT

my $grammar = Marpa::R2::Scanless::G->new({source => \$rules});

for (split /^/m, $input) {
    chomp;
    if (length $_) {
        print "\nPARSING: $_\n";
        
        my $recce = Marpa::R2::Scanless::R->new({
            grammar => $grammar, 
        });
        
        my $value_ref = $grammar->parse( \$_);
		print Dumper $$value_ref;
    }
}

__OUTPUT__

PARSING: add 192.0.2.1
$VAR1 = [
          [
            'add'
          ],
          [
            [
              '192.0.2.1'
            ]
          ]
        ];

PARSING: add www.example.org
$VAR1 = [
          [
            'add'
          ],
          [
            [
              'www.example.org'
            ]
          ]
        ];

PARSING: remove 192.0.2.2
$VAR1 = [
          [
            'remove'
          ],
          [
            [
              '192.0.2.2'
            ]
          ]
        ];