> BC break Hm, do you really think so? I wouldn't say removing the final attribute from enums actually "breaks" any functionality.
It WOULD allow some potentially illicit hacking to the end users of our code, that's true. I'd say a minor possibility of impact. And anyway, isn't that what got you to fall in love with PHP in the first place? Some good ol' illicit hacking of some dude's library :) On Wed, 29 Mar 2023 at 12:22, Marco Pivetta <ocram...@gmail.com> wrote: > > Hey Rokas, > > The idea of declaring an enum `abstract` is potentially worth exploring (I'm > not convinced, but go for it), but beware that removing the implicit `final` > from ENUMs is a BC break, since it breaks the assumption that an ENUM is a > sealed type. > > If you design a proposal now, you need to consider that `final` as the > implicit default is an existing contract that really enables ENUM usage. > > Marco Pivetta > > https://mastodon.social/@ocramius > > https://ocramius.github.io/ > > > On Wed, 29 Mar 2023 at 11:05, Rokas Šleinius <rave...@gmail.com> wrote: >> >> > to restrict options within a certain range. >> Okay that's an aspect of enums that I never gave much thought to, but >> you're completely right. >> >> However to be explicit about that aspect of functionality one would >> then have to also be >> allowed to define final enums. >> >> That way you still have both options - to restrict the option set, but >> to also allow adding >> custom ones while benefiting from other enum advantages. >> >> Thus, rfc idea seems to be: >> * enums should be able to extend other enums; >> * abstract enums; >> * enums allowed to implement interfaces; >> * final enums (NEW!) >> >> >> >> > BackedEnum&MyCustomBehaviorInt >> That's a fascinating approach but to a different problem than illustrated in >> OP. >> >> Would you mind sharing (in private preferably to not distract from the >> discussion) the >> gist of the problem this solves? I'm really curious, as I've yet to >> use intersect types :)! >> >> On Wed, 29 Mar 2023 at 11:47, Robert Landers <landers.rob...@gmail.com> >> wrote: >> > >> > On Wed, Mar 29, 2023 at 10:31 AM Rokas Šleinius <rave...@gmail.com> wrote: >> > > >> > > Enums were a very useful addition to PHP, however one aspect of them is >> > > neither >> > > explicitly documented - or seemingly even talked about. >> > > >> > > Enums were implemented as final so they cannot be extended nor can extend >> > > anything else. >> > > >> > > From a user perspective it's surprising - and actually limiting. >> > > >> > > USAGE EXAMPLE: >> > > I am making an error management system: each error presented to the user >> > > must have a unique code visible. >> > > >> > > ```php >> > > class SystemError >> > > { >> > > public function __construct( >> > > private string $errorText, >> > > private ErrorCode $code >> > > ) { >> > > } >> > > >> > > public function __toString(): >> > > { >> > > return $this->errorText . ' ' . $this->code->toString(); >> > > } >> > > } >> > > // ... >> > > >> > > enum ErrorCode >> > > { >> > > case Code_1; >> > > case Code_2; >> > > >> > > public function toString(): string >> > > { >> > > return 'Error code:' . substr($this->name, strlen('Code_')); >> > > } >> > > } >> > > ``` >> > > >> > > Now I want to modify it to support different modules with different >> > > namespaces for >> > > errors, e.g. an ApiError, simple enough: >> > > >> > > ```php >> > > enum BaseErrorCode >> > > { >> > > // ... >> > > } >> > > >> > > enum ErrorCode extends BaseErrorCode >> > > { >> > > case Code_1; >> > > case Code_2; >> > > >> > > // ... >> > > } >> > > >> > > enum ApiErrorCode extends BaseErrorCode { >> > > // ... >> > > function toString(): string >> > > { >> > > return 'Error code:API-' . substr($this->name, strlen('Code_')); >> > > } >> > > } >> > > ``` >> > > >> > > This results in a syntax error. >> > > >> > > PROPOSAL: >> > > >> > > Enums should be able to extend other enums. >> > > >> > > For a complete wishlist, add: >> > > * abstract enums; >> > > * enums allowed to implement interfaces; >> > > >> > > However since I have no experience in PHP source code, I can only >> > > provide the test suite for a possible PR this might have :( >> > > >> > > Do you think this is likely to get implemented? >> > > >> > > -- >> > > PHP Internals - PHP Runtime Development Mailing List >> > > To unsubscribe, visit: https://www.php.net/unsub.php >> > > >> > >> > Hey Rokas, >> > >> > My approach has been to use an intersection type like: >> > BackedEnum&MyCustomBehaviorInterface >> > >> > This works for me but it'd be interesting if something like that >> > wouldn't work for you. >> >> -- >> PHP Internals - PHP Runtime Development Mailing List >> To unsubscribe, visit: https://www.php.net/unsub.php >> -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
