Visibility for classes

[ghost]

Hi, at his talk on LARACON EU, Roman Pronskiy asked to throw ideas here.

My idea is to have a visibility for classes like it is in languages such as Java or C#. I think this would result in better and safer code that doesn't end up as spaghetti monolith. Let's protect developers from themselves. Right now one has to depend on other developer programming ethic which is a very naive approach 😄

The private visibility would be the default.

However I have no idea how this can be introduce with the PHP namespaces. Which namespace would be a root one and as such considered "a module"? Would it be configurable somehow and all the subnamespaces will be considered the part of this "package"/"module"?

[pronskiy]

@javaDeveloperKid, this has been discussed and even implemented in the past php/php-src#947.

Later there was an RFC for sealed classes, which is a similar concept https://wiki.php.net/rfc/sealed_classes.

Not sure if anyone is currently interested in reviving this idea as the RFC above failed to pass voting.

Meanwhile, @internal annotation and static analysis tools can help https://docs.phpdoc.org/3.0/guide/references/phpdoc/tags/internal.html#internal.

[pronskiy]

It seems like @azjezz is working on a new sealed classes implementation 🙌
https://twitter.com/azjezz/status/1781960006608290143

[ghost]

Thank you for the response.
I can see the PR dates back to 2014. It's been 10 years so revisiting this topic could bring new attitude and new approach.

About sealed classes, it's not that similar concept. Visibility is about calling a class from other namespace and sealed classes is about inheritence. Correct me if I'm wrong.

[azjezz]

Yes, sealed classes is mainly about inheritence. if a class is sealed within a namespace, e.g:

namespace Lib;

sealed class Foo permits Bar, Baz { ... }

final class Bar extends Foo { ... }
final class Baz extends Foo { ... }

It can still be used in other namespaces, e.g:

namespace App;

use Lib\{Foo, Bar, Baz};

$foo = new Foo();
$bar = new Bar();
$baz = new Baz();