Re: RFC proposal: Invokable interface

Hi! On 30/03/2026 00:42, Osama Aldemeery wrote:

It follows the Stringable pattern: auto-implemented for any class defining __invoke(), explicitly implementable with enforcement, and covariant to callable in return type checks.

Stringable is just a normal interface that can be used directly as any other regular interface, it's just also applied magically. Invokable cannot be a regular interface because the signature for __invoke is not fixed, so it's a "weird" interface with magic behavior like Throwable and Iterable. What is common about these weird interfaces is that they can't be directly implemented by user. I don't feel like breaking this rule is a good idea for something with no clear benefits. Second thing is that magic methods are not supposed to be used directly, so having __invoke is just an implementation detail, the consumer code should not check for that, that's a code smell. Anton