I don't see a point in repeating the discussion we've already had on that topic several weeks ago. There needs to be an overwhelmingly good reason to add a brand new syntax to the language, a whole branch of it in the case of annotations - and there simply isn't.
Zeev > -----Original Message----- > From: guilhermebla...@gmail.com [mailto:guilhermebla...@gmail.com] > Sent: Monday, November 15, 2010 7:08 PM > To: PHP internals > Subject: [PHP-DEV] PHP 5.4 - Meta attribute (aka. Annotations) support > discussion > > Hi folks, > > I'll start a series of topics (in this thread) about meta attribute (aka. > Annotations) discussion. > So as soon as we agree on each topic I'll open another point to be discussed. > Only when we reach some consensus I'll open another topic discussion. > I suggest to have a poll for each topic, so we can do some democratic > internals decision. I'd reduce the scope of voters to only people with PHP > karma. > > The first topic to be defined is: Does PHP need meta attribute support? > > Any language is built at the top of syntax, words, semantics and context. > We cannot define it as a language if we don't have these 4 parts well fit > together. > For a simple sentence like: I am all ears, we can easily identify these parts. > But the real meaning of this sentence (context) is only achieved with another > part of the language: signifier-significate. > A signifier is an atomic form, material element, visible, sensitive. > A significate is an idea, semantic content, conceptual element, not sensitive > perceptive. > > This important part is only reminded when we get back to semantics, > specifically when talking about idiomatic expressions, a metaphor in our > sample. The meaning will only work if we have the context, a known > information. Our sentence would mean that spoker person only have ears, > while the true meaning is that he/she is paying attention. > A computer language doesn't differ from a language by any means. We have > tokens (words), a syntax, semantic. But the lack of contextualization brings a > hole on language and how your application should behave. This behavior can > be achieved by many different ways; the simplest way is known as meta > information. > > Considering you have a lack of idiomatic expressions knowledge of someone > that is reading. He'd think person only have ears, but if you meta notify him > that it is a metaphor, he'd try to find a different meaning. Example: > (Metaphor) I am all ears. > > Now that we find how meta-information can benefit languages, it is time to > understand how meta-information can benefit a computer language. > > A good example is define a Service that validates Domain Objects. > Imagining a scenario where you have a User class that holds email and > password. Email and password fields must be validated, for example, email > as an email and password with at least 6 chars. A generic validation service > could not have the User validation hardcoded inside the service, so the > solution would be an external factor that explains to service how to validate > the DO. One of the possible implementations would be a UserValidator class > that contains validation rules for each field. This external factor is a good > sample of meta-information. But how would a meta attribute would solve > this situation? > A Service could simple retrieve the validation instructions by Reflecting the > class which instance is going to be validated. > Basically, to validate a Domain Object, it is simply required to add > validation > rules on desired attributes. Example: > > class User { > <Email Meta Information> > protected $email; > > <At least 6 chars Meta Information> > protected $password; > } > > *NOTE*: Please understand that this do not enter in any implementation > details. It is not time (yet) to talk baout docblock, new syntax, etc. > Scope now is simpler than that. > > Now that is possible to see how meta attribute support could benefit a > language, I compiled a simple list of known projects and how can they > benefit of meta support: > - phpUnit Providing meta functionality for test cases, examples: > @dataProvider for test data iteration, @expectedException for catching > exceptions, etc. > - Doctrine For Object-Relational mapping, examples: @Entity, @OneToOne, > @Id, etc. > - Zend Framework Server classes Used to automate mappings for XML-RPC, > SOAP, etc. > - FLOW3 for dependency injection and validation > - Symfony2 for validation and routing rules > - Others: Validation, Functional Behavior injection (which could take > advantage of Traits), etc. > > > Poll will be opened for voting for 7 days (1 week) starting from now. > Poll will be closed next Monday at 5pm GMT. > Question: Does PHP need meta attribute support? > > Happy voting! > > -- > Guilherme Blanco > Mobile: +55 (16) 9215-8480 > MSN: guilhermebla...@hotmail.com > São Paulo - SP/Brazil > > -- > PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: > http://www.php.net/unsub.php
