Parse::EBNF::Rule

The Parse::EBNF::Rule is a Perl module that is designed to parse a single EBNF production into a tree of Parse::EBNF::Token objects. This feature is particularly useful for those who are working with complex EBNF productions and need to have an organized structure to manage them.

To utilize the module, the SYNOPSIS is as follows:
```
use Parse::EBNF::Rule;
my $input = "[1] MyRule ::= 'foo' | 'bar'";

# parse a rule
my $rule = Parse::EBNF::Rule->new();
$rule->parse($input);

# OR

my $rule = Parse::EBNF::Rule->new($input);

# check if parsing succeed
die $rule->error() if $rule->has_error();

# get the root token for this rule
my $token = $rule->base_token();
```
One can seamlessly integrate the Parse::EBNF::Rule module into their workflow to make the parsing of EBNF productions effortless. If an error occurs during parsing, the error message is provided with the `error()` method. Additionally, the `base_token()` method allows one to retrieve the root token of the given EBNF rule.

Overall, the Parse::EBNF::Rule module is a reliable and powerful tool for parsing EBNF productions into a manageable structure. Its ease of use and error handling capability make it a valuable addition to any developer's toolkit.