Re: [Proposal] Introduce is operator

On Wed, Jun 21, 2023, at 5:44 PM, Удальцов Валентин wrote: > Hi internals, > > Today PHP is more typed than ever, however, one feature is still missing: > ability to check complex variable types using standard type declarations. > > For example, to check that $var is a nullable string one has to do > assert($var === null || is_string($var)). To check that $var is > false or > a countable iterator, one has to write `assert($var === false || ($var > instanceof Countable && $var instanceof Iterator))`. > > I propose to add a new "is" operator that allows to have `assert($var is > ?string) and assert($var is false|(Countable&Iterator))`. > So it is > similar to instanceof, but accepts any valid PHP type declaration on the > right side. > > WDYT? > > Regards, > Valentin There's already an RFC for that in the works, from Ilija and I: https://wiki.php.net/rfc/pattern-matching "In the works" in this case means it's been designed and some preliminary code written a while ago, but nothing submittable yet. We're hoping to get back to it in 8.4, as it's going to be a prerequisite for ADTs being usable. (cf: https://wiki.php.net/rfc/tagged_unions, though the design there is out of date.) So... hopefully stay tuned. --Larry Garfield