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

use Marpa::R2;
my $grammar_spec    = get_grammar();
my $test_input      = test_input();

my $grammar = Marpa::R2::Scanless::G->new({ source => \$grammar_spec, });
my $recce = Marpa::R2::Scanless::R->new({ grammar => $grammar });

$recce->read(\$test_input);

my $val = $recce->value;


sub get_grammar {
    return <<'END_GRAMMAR';
    :start              ::= Alias
    :discard            ~ ws

    Alias               ::= 'User_Alias'  User_Alias (':' User_Alias)*
    User_Alias          ::= NAME '=' User_List
    User_List           ::= User
                        | User ',' User_List

    User                ::= <user name>
    NAME                ~ [A-Z]([A-Z][0-9]_)*
    ws                  ~ [\s]+
    <user name>         ~ [a-z]([a-z][0-9]_)*

END_GRAMMAR
}

sub test_input {
    return <<'END_INPUT';
User_Alias FOO = abc, def
END_INPUT
}