----- Original Message -----
> From: "Gabriel Caruso" <carusogabriel34@gmail.com>
> To: "internals" <internals@lists.php.net>
> Sent: Monday, April 2, 2018 11:17:43 AM
> Subject: [PHP-DEV] [RFC][Discussion] Make compact function reports undefined passed variables
> Hello dear internals, how are you?
>
> I'd like to propose a new RFC to PHP's core, but as this one contains a BC
> Break, let's discussed it before making anything official.
>
> A couple of days ago, while discussing some [Coding Standards rules for
> Doctrine, forbidden the `compact` function](
> https://github.com/doctrine/coding-standard/pull/49), an argument caught my
> attention:
>
>> The `compact` function var does not report undefined variables.
>
> Looking in [the `compact` documentation](https://secure.php.net/compact),
> this is even emphasizes:
>
>> Any strings that are not set will simply be skipped.
>
> I couldn't figure out why this is done this way, but, here's what I'd like
> to propose: make the `compact` function starts to report undefined passed
> variables for it.
>
> With [only 2 lines of code](
> https://github.com/php/php-src/compare/master...carusogabriel:warning-unknow-compact-variable),
> this is possible, but, of course, this is a BC Break.
>
> Let me know your opinion on that, and perhaps, make it happen!
>
> Regards,
> --
> Gabriel Caruso
Hey Gabriel,
What I am missing here is the reason why we should break well defined behavior of existing functions.
How is the BC break for all existing code justified?
Pieter