#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

use Data::Dump;
use Marpa::R2;

my $dsl = <<'__DSL__';
lexeme default = latm => 1
:default ::= action => ::first

Entry      ::= op Hostaddr4        action => entry
Hostaddr4  ::= Hostname            action => add_hostname
             | Ipv4
Hostname   ::= Domains '.' ext     action => concat
Domains    ::= domain '.' Domains  action => concat
             | domain
Ipv4       ::= number ('.') number ('.') number ('.') number
                                   action => add_ip

op           ~ 'add' | 'remove'
domain       ~ [\d\w]+
ext          ~ 'org' | 'net'
number       ~ [\d]+
:discard     ~ whitespace
whitespace   ~ [\s]+


__DSL__

my $input = << '__INPUT__';
add example.org
add www.perl.org
add 42.perl.net
add 192.0.2.1
remove 192.0.2.2

__INPUT__

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

open my $in, '<', \$input;
while (<$in>) {
    chomp;
    next unless length;
    say "PARSING: $_";
    my $recce = 'Marpa::R2::Scanless::R'->new({
        grammar           => $grammar,
        semantics_package => 'main',
    });
    # Uncomment for debugging:
    # warn $recce->show_progress(0);
    $recce->read(\$_);
    dd ${ $recce->value };
}

sub add_ip       { { type => 'ip', ip => join '.', @_[1 .. $#_] } }
sub concat       { shift; join "", @_ }
sub add_hostname { { type => 'hostname', hostname => $_[1] } }
sub entry        { { operator => $_[1], %{ $_[2] } } }

__DATA__
PARSING: add example.org
{ hostname => "example.org", operator => "add", type => "hostname" }
PARSING: add www.perl.org
{ hostname => "www.perl.org", operator => "add", type => "hostname" }
PARSING: add 42.perl.net
{ hostname => "42.perl.net", operator => "add", type => "hostname" }
PARSING: add 192.0.2.1
{ ip => "192.0.2.1", operator => "add", type => "ip" }
PARSING: remove 192.0.2.2
{ ip => "192.0.2.2", operator => "remove", type => "ip" }
[download]