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Date: Thu, 13 Sep 2012 16:41:57 -0500
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To: Stas Malyshev <smalyshev@sugarcrm.com>
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Subject: Re: [PHP-DEV] Re: [VOTE] ::class feature to resolve namespaced class
 names to scalars
From: ralph@ralphschindler.com (Ralph Schindler)

Hey Stas,

>> * Here are the edge cases / implementation details that need a decision:
>>
>>     - $variable::class (should it even be supported?)

> I don't see it doing anything useful.

I generally agree.

In the current patch, this does not work and would need another run in 
the parser.

>>     - self, static, parent::class not in a class definition
>>     - self, static, parent::class in a method signature
>>     - self, static, parent::class in a method body
>
> In constant context, self:: may work, but static:: can't work for
> obvious reasons. parent:: can be made work too I think - though the
> class may not be known at the run time, its name should be.

self works in compile-time in the current patch.

static::class and parent::class work in the current patch in run-time, 
but they are effectively doing a get_called_class() and 
get_parent_class() respectively.

This part of my implementation can be cleaned up to remain in runtime 
but utilize zend_do_fetch_class() instead.

> As for runtime context, static:: can be made work too but I wonder why
> bother if we have perfectly good get_called_class()...

For some people, I think it's a matter of completeness, regardless if it 
is a compile-time name resolution or a runtime class lookup. 
Personally, (I am not the majority here I feel), I'd rather see 
zend_error(E_FATAL) for any runtime lookups, forcing people to use the 
runtime-lookup-isms (like get_called_class(), or get_parent_class()). 
For the latter, returning "false" there seems more likely, where as 
parent::class returning false when not in an inherited class seems odd 
to me.

-ralph