Re: [RFC] __exists(), a magic method for distinguishing "missing" from "set to null"

On Fri, May 1, 2026, at 4:37 AM, Nicolas Grekas wrote: > Dear internals, > > It's my pleasure to submit this new RFC to yours. > Please have a look and let me know: > https://wiki.php.net/rfc/exists-magic-method > > TL;DR: I'm proposing a new opt-in magic method: > > public function __exists(string $name): bool; > > It'd let userland tell "set to null" apart from "missing" on objects, > it'd restore > isset() <=> ?? equivalence on magic properties, and it'd fixe GH-12695 > as a > corollary. It's forward-compatible as a regular method on PHP <= 8.5 > (probeable > via method_exists()), and would be magic on 8.6+. > > Cheers, > Nicolas Thanks for the very detailed RFC! > If it returns false, the fetch produces “uninitialized” (treated as null by ??, so y is > evaluated). __get() is not called. What is y? Looks like a reference to a previous iteration of the text. The Sequencing section also doesn't describe the behavior when __exists() isn't defined. Does it just skip to step 4? (Please specify in the text.) Is the intent to eventually deprecate __isset()? The RFC it doesn't now, but do you feel that is the eventual end-game, in PHP 10 or whatever? The big one: Should any parallel changes or additions be made to property hooks? An exists() operation in addition to get/set, for instance? (I'm not sure at the moment, but it should be thought through and discussed, and if not, documented in the RFC.) --Larry Garfield