On Wed, Oct 2, 2024 at 11:06 AM Rob Landers <rob@bottled.codes> wrote:
> On Wed, Oct 2, 2024, at 09:20, Alexandru Pătrănescu wrote: > > > On Wed, Oct 2, 2024 at 1:48 AM Juliette Reinders Folmer < > php-internals_nos...@adviesenzo.nl> wrote: > > L.S., > > After the earlier discussion [1] regarding this topic in August, it is our > pleasure to present the RFC to add a `get_declared_enums()` function to PHP > for discussion. > > https://wiki.php.net/rfc/get_declared_enums > > We look forward to your feedback and hope for a constructive discussion. > > > I'm all for `get_declared_enums()`. > However, I don't accept that enums are not classes and going with the > assumption that they are not will bring more problems than it solves. > > I noticed how you analyzed things internally, that everything is a class > internally, including an interface or a trait. > But this is an API for the userland, and in userland this is not true. > The 3 structures: classes, interfaces and traits and distinct things that > you can use in different ways in (generated) code. > > I believe that in userland, the common understanding is that enums are > just a specific type of class, final ones. > I would find it surprising if `get_declared_classes()` would not return > enums. > > Avoiding a BC break would be nice also if there is no reason for it. > One would be able to get only the enums by using something like: > ```php > function get_declared_enums_only() { > return array_diff(get_declared_classes(), get_declared_enums()); > } > ``` > > -- > Alex > > > Interesting observation Alexandru, > > I find it weird that class_exists("MyEnum") would return true, but there > is only one symbol table—you can’t name a class and enum with the same > name, so it makes some sense. However, while enums have “some” similarities > with classes in PHP, they are not the same. For example, you cannot > implement arbitrary interfaces (ie, Stringable), you cannot extend another > class, you cannot instantiate them with “new”, you cannot have state, you > cannot clone them, magic methods are forbidden, etc. > > You cannot build a “class” with these rules in PHP, so I don’t think enums > quack sufficiently like classes to be called a class. I would argue that it > is an object, however. I think it would be worth implementing a > get_declared_objects() that behaves like get_declared_classes() currently > does. > > — Rob > Yes, that's a good point as well. I think my view comes from when I initially dug (15+ years ago) into what an enum in Java is, and learned that it is just a syntactic sugar, and a final class would be generated implementing `Comparable` and extending an abstract class `Enum`. And I think in PHP that could be a similar view. And most of the limitations we have are not impossible to create with a standard class. I think in time we might get to remove some limitations. I, personally, don't agree with the `Stringable` related limitation. And also with the limitation on no state. In Java this is the simple way to create a singleton: an enum with one case; and we can't have this in PHP. If we remove the limitations, should we reclassify at that point enums as classes? -- Alex
