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

use Data::Dumper;
use Term::ANSIColor qw(:constants);
use Marpa::R2;

my $rules = <<'END_OF_GRAMMAR';
    lexeme default  = latm => 1
    :default        ::= action => [name,values]
    :start          ::= <entry>

    <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 $_) {
        print "\n\n$_\n";
        
        my $recce = Marpa::R2::Scanless::R->new({
            grammar => $grammar, 
            ranking_method => 'rule'
        });
        
        eval { $recce->read(\$_ ) };
        print ($@ ? (RED . "$@\n") : GREEN);
        print $recce->show_progress(), "\n";
        print Dumper($recce->value), "\n\n", RESET;
    }
}

##</code><code>##

<hostaddr4>     ::= <ipv4> | <hostname>

<hostaddr4>     ::= <ipv4> || <hostname>

<hostaddr4>     ::= <hostname> | <ipv4>

<hostaddr4>     ::= <hostname> || <ipv4>

<hostaddr4>     ::= <ipv4>      rank => 2
                  | <hostname>  rank => 1


<hostaddr4>     ::= <ipv4>      rank => 1
                  | <hostname>  rank => 2


<hostaddr4>     ::= <ipv4>      rank => 1
<hostaddr4>     ::= <hostname>  rank => 2

<hostaddr4>     ::= <hostname>  rank => 1
<hostaddr4>     ::= <ipv4>      rank => 2