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Reply-To: "Eugene Leonovich" <gen.work@gmail.com>
References: <4F89D4F1.8070009@ralphschindler.com>
Date: Fri, 13 Jul 2012 14:48:20 +0200
Lines: 73
Subject: Re: New Feature: Fully qualified class name resolution as scalar with class keyword
From: gen.work@gmail.com ("Eugene Leonovich")

I'm a bit confused by the "class" keyword in the syntax ClassName::class.
We already have the magic constant __CLASS__ which does exactly the same 
class name resolving, if you refer it within the class.

So why to introduce a new keyword instead of using __CLASS__, like 
ClassName::__CLASS__?

Eugene

"Ralph Schindler" <ralph@ralphschindler.com> wrote in message 
news:4F89D4F1.8070009@ralphschindler.com...
> Hi all,
>
> There are many different use cases were in code we expect classes names as 
> arguments to functions as fully qualified names.  We do this in ZF a lot 
> with our Service Location and DI components, but also with our code 
> reflection API, etc.  A more interesting use case I would like to call out 
> is with PHPUnit, for example in a test, you might find this:
>
>   $mock = $this->getMock('A\Namespaced\ClassName');
>
> This becomes cumbersome when you are dealing with lots of strings about 
> lots of class names.  This is also an area where, currently, namespace 
> declaration and use statements offer no real support.
>
> The patch located here:
>
> https://github.com/ralphschindler/php-src/commit/02210d51851a96d723fbedcfc64cde9f9ae2b22a
>
> ... implements the ability for a developer to leverage the file's 
> namespace declaration and use statements to be able to produce a scalar 
> (string) of the class name that can be then used, for example, as an 
> argument to a function elsewhere.
>
> This overloads the "class" keyword, and by virtue of the existing usage of 
> "class" this feature is completely backwards compatible.  All existing 
> tests pass.  For example, the above PHPUnit snipped would become:
>
>   use A\Namespaced\ClassName;
>   $mock = $this->getMock(ClassName::class);
>
> Another example with reflection:
>
>   use SomeOther\FullyNamespaced\ClassElsewhere as CE;
>   $r = new ReflectionClass(CE::class);
>
> More examples from the test file:
>
>   namespace Foo\Bar {
>     class Baz {}
>     var_dump(Moo::CLASS); // "Foo\Bar\Moo"
>   }
>
>   namespace {
>     use Bee\Bop as Moo,
>         Foo\Bar\Baz;
>
>     var_dump(Baz::class); // "Foo\Bar\Baz"
>     var_dump(Boo::class); // "Boo"
>     var_dump(Moo::CLASS); // "Bee\Bop"
>     var_dump(\Moo::Class); // "Moo"
>
>     $class = Baz::class; // assign class as scalar to var
>     $x = new $class;
>     var_dump($x);  object(Foo\Bar\Baz)#1 (0) {}
>   }
>
>
> What do you guys think?
>
> -ralph