An example PHP file must contain a `return` statement which returns an array if the
the file is included.

{{{
<?php
return array(
	'postalCode' => '\d+',
	'phone' => '\d+\-\d+'
);
?>
}}}

The adapter works with a directory structure below. The example shows the structure
for the directory as given by the `'path'` configuration setting. It is similar to
the one used by the the `Gettext` adapter.

{{{
resources/g11n/php
├── <locale>
|   ├── message
|   |   ├── default.php
|   |   └── <scope>.php
|   ├── validation
|   |   └── ...
|   └── ...
├── <locale>
|   └── ...
├── message_default.php
├── message_<scope>.php
├── validation_default.php
├── validation_<scope>.php
└── ...
}}}