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	<1294276068.10675.3.camel@guybrush>
Date: Wed, 5 Jan 2011 18:51:51 -0700
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To: =?ISO-8859-1?Q?Johannes_Schl=FCter?= <johannes@php.net>
Cc: Martin Scotta <martinscotta@gmail.com>, internals@lists.php.net
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Subject: Re: [PHP-DEV] RFC: about class names as values
From: john.lesueur@gmail.com (John LeSueur)

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2011/1/5 Johannes Schl=FCter <johannes@php.net>

> On Wed, 2011-01-05 at 21:53 -0300, Martin Scotta wrote:
> > $obj =3D newInstance( MyClass ); // notice. undefined constant MyClass
>
> This describes the major change with your idea.
>
> What happens if a constant MyClass exists?
>
> Another question is something like this:
>
> <?php
> function  factory($class) {
>    return new $class();
> }
>
> factory( SomeClass );
> ?>
>
>
> To proper support this we'd have to make classes first class elements.
> For making this consistent it would make sense to make functions first
> class elements. And best drop the $ in front of variables and create a
> new language. Everything else becomes a mess.
>
> johannes
>
>
>
> --
> PHP Internals - PHP Runtime Development Mailing List
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>
>
I think he's actually proposing creating for each class the magic class
constant CLASS, so your example becomes:

<?php

function factory($class) {
    return new $class();
}

factory( SomeClass::CLASS );

?>

This is actually doable without a magic class constant, but requires a
function or class constant to be declared in each class.

<?php
class SomeClass {
    const CLASS =3D __NAMESPACE__ . '\' . __CLASS__;
    static function getNameWithNSPath()
    {
        return __NAMESPACE__ . '\' . __CLASS__;
    }
}


factory( SomeClass::getNameWithNSPath() );
?>

Perhaps this could be simplified with traits, if __NAMESPACE__ and __CLASS_=
_
work in traits that way. In fact, that's an interesting question, what is
__NAMESPACE__ in a trait defined in one namespace, then used in a class in =
a
different namespace?

I think the point is that the factory function could exist without any
knowledge of the namespaces of the classes it would work on. Then, somewher=
e
else where the class has been aliased or is otherwise accessible without th=
e
full namespace path, the developer wouldn't need to specify the full
namespace path to the factory, but could ask the class itself what it's ful=
l
namespace path was. I don't know that I agree with the idea, but I don't
think it requires making classes first class elements.

John

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