Re: Type hinting

On Tue, Jun 1, 2010 at 10:11 PM, Stas Malyshev <smalyshev@sugarcrm.com>wrote: > Hi! > > > Also, it never makes sense to convert one object type into another, and >> >>> almost never this operation can be defined. >>> >> >> >> array and ArrayObject? >> > > This is a good example because strict typing would probably reject > ArrayObject passed as array, thus defeating the whole purpose of having > ArrayObject. Yeah, I know, this is why I said. > That's exactly why we have to be very careful with strict types in dynamic > language - because it makes excellent dynamic extensions line ArrayObject, > __toString, etc. useless - since you can not really use one type instead of > another as they intend, strict typing kills that. > Coercive typing, on the other hand, would work just fine with those. Agree. > > > I mean it's too late to argue about that the current type hinting triggers >> an error in case of type mismatch. >> > > Actually we could change it if we wanted to, I don't believe there's really > some code that relies on it being error for some functionality. The question > is what we'd change it to, for which I have no good answer. > > As I mentioned, I think that we have to inform the caller about the problem (be either a type or a conversion mismatch), so the only options to trigger an error, or throw an exception. I like the exception idea better, because it can be easily handled localy (no need to register a global error handler), but as the core devs said, it isn't allowed to throw exceptions from the core, so this is why I think, that the weak type hinting should be implemented as an spl interface. This way we could even support array - ArrayObject conversion too. http://wiki.php.net/rfc/splweaktypehintingwithautoboxing The rfc name sucks, but I couldn't come up with a better one. Tyrael