Re: RFC: Traits for PHP

Hello Stefan, any dynamic aspect of a class has brought us to problems in inheritance and required us to design the objct/compile model in a way that inheritance often is done at run time. Imo traits are a way out of this. In fact I'd love to issue a deprecated message as soon as class is found outside of a main block. marcus Tuesday, February 19, 2008, 12:36:32 AM, you wrote: >> So it's just like an include for a re-used body of 'class' code. >> >> Hmmmm. >> >> Why not just allow 'include' here instead? > Well, think this would be a Mixin mechanism like in Ruby. >> Forgive me if I'm missing something subtle/complex here, but I wonder >> if a Trait is really the "right answer"... >> >> Yes, the ability to add/exclude specific functions from two Traits is >> "gone" with a simple 'include'... But so is the complexity of yet >> another language construct... > The problem here is that we will need a way to handle conflicts i.e. > methods defined in more than one of the includes. > The mixin way is to apply one include at a time. So conflicts are > solved by overriding already defined methods. But this solution is not > perfect at all since there exist situations where you can not find an > order for the includes which provides you with the needed method > implementations. Additionally you will not notice when a method in an > included hierarchy will break your semantics by overriding other > methods unexpectedly. > The Traits way is to enable the developers to decide on such conflicts > and give them the power to re-use the methods exactly needed in this > special situation, instead of doing some "magic"/linearization to > solve conflicts. > Kind Regards > Stefan Best regards, Marcus