Re: Let's discuss enums!

On Sep 17, 2015, at 19:16, Bob Weinand <bobwei9@hotmail.com> wrote: > >> Am 18.09.2015 um 01:06 schrieb Rowan Collins <rowan.collins@gmail.com>: >> >> This has come up in passing a few times recently, but I'm not sure there's ever >> been a dedicated discussion of it: would it be useful for PHP to have a built-in Enumeration type, >> and if so, how should it look? > > I like enums in general, but I'd like to note that there's already a RFC in draft by > Levi: > > https://wiki.php.net/rfc/enum > <https://wiki.php.net/rfc/enum> > > As far as I know, the RFC is already fairly final and just lacks an implementation. > > So, I'd consider bikeshedding an actual RFC first. If we’re bikeshedding, one feature I would really like to see, with typehinting, is warnings if all cases of an enum aren’t handled in a switch. So, for example, given our example Weekdays enum, if I wrote this code: switch(Weekday $someWeekday) { case Weekday::MONDAY: break; case Weekday::TUESDAY: break; } By providing the typehint, I’m indicating that I want to get a warning/error that the switch does not cover all enum values. This would be very handy if an enum value is added after initial development and someone misses a switch statement in cleanup. The typehint would also allow generating a warning if someone did something like switch(Weekday $someWeekday) { //case … all the weekdays: break; case ‘I am not a Weekday’: echo ‘Generate a fatal error here because string is not a Weekday.’; } -John