Req->Bug #72903 [Opn->Csd]: Spec does not allow $objInstance->memberObj::$staticVar syntax

Edit report at https://bugs.php.net/bug.php?id=72903&edit=1

 ID:                 72903
 Updated by:         [email protected]
 Reported by:        dliebner at gmail dot com
 Summary:            Spec does not allow
                     $objInstance->memberObj::$staticVar syntax
-Status:             Open
+Status:             Closed
-Type:               Feature/Change Request
+Type:               Bug
-Package:            Scripting Engine problem
+Package:            PHP Language Specification
 PHP Version:        7.0
-Assigned To:        
+Assigned To:        nikic
 Block user comment: N
 Private report:     N

 New Comment:

The spec @ https://github.com/php/php-langspec/blob/master/spec/10-expressions.md#scope-resolution-operator now specifies the syntax correctly.


Previous Comments:
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[2016-08-20 02:58:29] [email protected]

PHP 5.6 does not support that syntax, and I don't think {}s can help with it. PHP 7 does. https://3v4l.org/ad03D


Looking at the spec [1], I see two problems with "$obj->childClass::$var":

1. $obj->childClass would be classified as a scope-resolution-qualifer > expression, which "must be a value of type string [...] that contains the name of a class or interface type". This is not true: objects are supported, as seen in

  class Example { static $foo = "bar"; }
  $e = new Example();
  echo $e::$foo; // bar

2. $var must be a member-selection-designator, however that is defined [2] as either a name (without a '$') or "a value of type string [...] that contains the name of an instance property (without the leading $) [or a method]". Neither of those cover the static property usage (which the prose for the scope-resolution operator calls "otherwise"), thus referencing member-selection-designator is insufficient; I think adding a ":: $ name" covers this case.

So I'm repurposing this bug to deal with the spec.


[1] https://github.com/php/php-langspec/blob/master/spec/10-expressions.md#scope-resolution-operator
[2] https://github.com/php/php-langspec/blob/master/spec/10-expressions.md#member-selection-operator

------------------------------------------------------------------------
[2016-08-19 22:51:29] dliebner at gmail dot com

Description:
------------
---
From manual page: http://www.php.net/language.oop5.static
---

Code sample below yields 'unexpected T_PAAMAYIM_NEKUDOTAYIM' syntax error.

Test script:
---------------
<?php 

class MyClass {
	
	public static $var = 'yay!';
	public $childClass;
	
	public function __construct() {
		
		$this->childClass = new ChildClass();
		
	}
	
}

class ChildClass {
	
	public static $var = 'yay?';
	
}

$obj = new MyClass();

echo $obj::$var; // works
echo $obj->childClass::$var; // syntax error

?>

Expected result:
----------------
yay!yay?

Actual result:
--------------
Parse error: syntax error, unexpected '::' (T_PAAMAYIM_NEKUDOTAYIM), expecting ',' or ';' in __FILE__ on line 25


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Edit this bug report at https://bugs.php.net/bug.php?id=72903&edit=1