[Question] Make MicroKernel a first-class citizen?

[javiereguiluz]

In previous Smyfony versions, microkernel was a questionable feature, added without much enthusiasm and implemented as a trait.

But in the new Symfony paradigm, the microkernel is a central part of it. Why not make it a real PHP class instead of a trait?

---

Before:

use Symfony\Component\HttpKernel\Kernel as BaseKernel;

class Kernel extends BaseKernel
{
    use MicroKernelTrait;

    // ...
}

After:

use Symfony\Component\HttpKernel\MicroKernel;

class Kernel extends MicroKernel
{
    // ...
}

[nicolas-grekas]

IMHO, because a MicroKernel is not a type, but a pure behavior. Making it a class would make it a type (ie one could do instanceof MicroKernel), which would be bad.

[fabpot]

I agree with @nicolas-grekas. That let's you have your own derivative of Kernel, but still have the behavior defined in the trait.