Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:30683
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain zend.com designates 212.25.124.162 as permitted sender)
To: <internals@lists.php.net>
Date: Mon, 9 Jul 2007 20:36:43 +0400
Message-ID: <000501c7c247$56a551d0$6e02a8c0@thinkpad>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
Importance: Normal
Subject: FW: Simple Namespace Proposal
From: dmitry@zend.com ("Dmitry Stogov")

I am going to commit this patch on Wednesday.

Thanks. Dmitry.

> -----Original Message-----
> From: Dmitry Stogov [mailto:dmitry@zend.com] 
> Sent: Wednesday, July 04, 2007 4:46 PM
> To: 'internals@lists.php.net'
> Subject: Simple Namespace Proposal
> 
> 
> Hi,
> 
> Please review the following concept and patch for php6...
> 
> http://dev.daylessday.org/diff/ns-06.diff.txt
> http://dev.daylessday.org/diff/tests.tar.gz
> 
> Main assumption of the model is that the problem that we are 
> to solve is the problem of the very long class names in PHP 
> libraries. We would not attempt to take autoloader's job or 
> create packaging model - only make names manageable. 
> 
> Namespaces are defined the following way: 
> 
> Zend/DB/Connection.php: 
> <?php 
> namespace Zend::DB;
> 
> class Connection {
> }
> 
> function connect() {
> }
> ?>
> 
> Namespace definition does the following: 
> All class and function names inside are automatically 
> prefixed with namespace name. Inside namespace, local name 
> always takes precedence over global name. It is possible to 
> use the same namespace in several PHP files. The namespace 
> declaration statement must be the very first statement in file.
> 
> Every class and function from namespace can be referred to by 
> the full name - e.g. Zend::DB::Connection or 
> Zend::DB::connect - at any time. 
> 
> <?php
> require 'Zend/Db/Connection.php';
> $x = new Zend::DB::Connection;
> Zend::DB::connect();
> ?>
> 
> Namespace or class name can be imported: 
> 
> <?php 
> require 'Zend/Db/Connection.php';
> import Zend::DB;
> import Zend::DB::Connection as DbConnection;
> $x = new Zend::DB::Connection();
> $y = new DB::connection();
> $z = new DbConnection();
> DB::connect();
> ?>
> 
> import statement only defines name aliasing. It may create 
> name alias for namespace or class. The simple form of 
> statement "import A::B::C::D;" is equivalent to "import 
> A::B::C::D as D;". Import statement can be used at any time 
> in global scope (not inside function/class) and takes effect 
> from the point of definition down to the end of file. It is 
> recommended however to place imports at the beginning of the 
> file. Import statements have effect only on file where they 
> are written.
> 
> The special "empty" namespace (:: prefix) is useful as 
> explicit global namespace qualification. All class and 
> function names started from :: interpreted as global. <?php 
> namespace A::B::C;
> 
> $con = ::mysql_connect(...);
> ?>
> 
> A special constant __NAMESPACE__ indicates the current 
> namespace. It can be used to construct fully-qualified names 
> to pass them as callbacks.
> 
> <?php
> namespace A::B::C;
> 
> function foo() {
> }
> 
> set_error_handler(__NAMESPACE__ . "::foo");
> ?>
> 
> In global namespace __NAMESPACE__ constant has value of empty string.
> 
> Names inside namespace are resolved according to the following rules.
> 
> 1) all qualified names are translated during compilation 
> according to current import rules. So if we have "import 
> A::B::C;" and then "C::D::e();" it is translated to "A::B::C::D::e()"
> 2) unqualified class names translated during compilation 
> according to current import rules. So if we have "import 
> A::B::C;" and then "new C();" it is translated to "new A::B::C()"
> 
> 3) calls to unqualified functions that are defined in current 
> namespace interpreted as calls to corresponding functions
> 4) calls to unqualified functions that are not defined in 
> current namespace are resolved in run-time. The call to 
> function foo() inside namespace (A::B) first tries to find 
> and call function from current namespace A::B::foo() and if 
> it doesn't exist PHP tries to call internal function foo(). 
> Note that using foo() in namespace you can call only internal 
> PHP functions, however using ::foo() you are able to call any 
> function from global namespace.
> 5) unqualified class names are resolved at run-time. E.q. 
> "new Exception()" first tries to use (end even __autoload()) 
> class from current namespace and in case of failure uses 
> internal PHP class. Note that using "new A" in namespace you 
> can call only create internal PHP class, however using "new 
> ::A" you are able to create any class from global namespace
> 6) Calls to qualified functions are resolved at run-time. 
> Call to "A::B::foo()" first tries to call function foo() from 
> namespace "A::B", then it tries to find class "A::B 
> (__autoload() it if necessary) and call its static function foo() 
> 7) qualified class names are interpreted as class from 
> corresponding namespace. So "new A::B::C()" creates class "C" 
> from namespace "A::B".
> 
> Thanks. Dmitry.
>