Hi internals, Library developers sometimes plan for extensibility of their code, but not all pieces are able to be extended and unexpected usage can lead to unpredictable behavior. Based on that, I consider it may be a good addition to PHP to add class visibility support and enhance existing modifiers' support.
First, we should discuss about possible enhancements on current existing class modifiers' support (abstract and final). Currently, just as an example, I can create a trait with abstract methods, but I cannot declare an abstract trait. My proposed enhancements are: - abstract traits: Currently we only add implicit abstract. We should allow explicit declarations too. Nothing to change in the overall support, seems just a scanner inclusion. - final traits: prevent to be composed in other traits - final interfaces: prevent to be extended in other interfaces By adding these minor additions, we may likely simplify the scanner a bit. This would also make easier to support class visibility in the scanner. Unfortunately, PHP does not support nested classes. Personally speaking, I feel that the language can live happy without it, as soon as we can have class visibility support. Now what I mean by class visibility, it requires a better discussion on how it could behave, since any other language relies on nested classes to expose this support. Nevertheless, PHP's lack of Open/Close principle support could be addressed easily. This is my POV on how it could behave: - private classes: Can only be extended and instantiated inside of the same namespace it sits. This is the similar to private-package support in Java. - protected classes: I can't determine any similarity to any other language in this one, but it could behave somehow like: can be extended and instantiated anywhere within the root namespace. - public classes: same as current PHP support What do you think about it? Cheers, -- Guilherme Blanco MSN: guilhermebla...@hotmail.com GTalk: guilhermeblanco Toronto - ON/Canada
