Hi interns. The official PHP.net documentation of the "PHP at the Core: A Hacker's Guide" section (https://www.php.net/manual/en/internals2.php) is obsolete.
In that sense Python has good documentation to be extended in C / C ++. I think this is also one of the reasons why there are libraries like NumPy and others that have popularized Python for data science. I personally know that the project http://www.phpinternalsbook.com exists. While this book is not yet fully updated to PHP 7, the information it provides is wonderful! I think the "A Hacker's Guide" documentation should clarify that it is outdated and incomplete and at least reference the project http://www.phpinternalsbook.com What do you think? Regards!