Hey #PHP folks 👋🏼 got a little twisty thing to noodle on:
If a class and an enum can equally implement an interface, does that mean it's safe to use them interchangeably when your method type-hints the interface that they both implement?
@Crell it's that funny syntax a d blocked features I'm worried about... like there might be some hidden edge-cases where if I assume it's a class and behaves like a class but I've got an enum and for some reason it doesn't behave the way I expect
I'm honestly struggling to think of a solid example, but I can't shake the thought that it's a possibility... I just haven't encountered it yet
@simonhamp@Crell I would wager that any such use, with a class or an enum, would be a violation of the interface. The contract in the interface is all you are promised. Nothing more.
@cabbey@Crell the only problem case I can see—and why I've decided against using the same interface on my enum as I would on a normal class—is the lack of support for clone
There will be some cases where it is necessary to clone the given object... if it's an enum, that's not possible
Unfortunately, the contract of the interface doesn't protect us there
@simonhamp@cabbey If your API design specifically depends on cloning, then yes, enums won't work. In practice, though, I find that unusual. Enums are value objects without associated values. It's like trying to clone the number 5.
@Crell@simonhamp@cabbey I used an interface on an enum this one time which had __toString. That didn't work because __toString doesn't work on enums. Interface in question was for colors so __toString pretty printed it.
@simonhamp@Crell@cabbey yeah the use of __toString is questionable. I was using it as a "debug representation" method. It was deliberately not supported on enums for reasons.
Hm, though that seems blocked on enums, too. That may make sense to unblock, maybe? Though an enum's var_dump() output is already pretty self-explanatory.
@Crell@simonhamp@cabbey that returns an array tho. this is "format this object as a string in a human way" for logging, debugging, whatever... and tbh I don't even care about casting to string. But somehow the ubiquitousness of __toString() and made it appealing for this case.
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