My full argument why const should be hoisted, while define() can't and shouldn't 
be:

const FOO = val; is a construct that doesn't depend on runtime conditions, much 
like class constants. It can't accept expressions, variables and can't be placed 
in conditional blocks, while define() is a function call that can accept 
variables and expressions and be placed in conditional blocks.

Therefore regardless of their opcode implementation, they are exposed in a 
fundamentally 
different way, and define() hoisting isn't expected while const hoisting is 
expected (as 
a static declaration, and similar to class const declaration, their position in 
the class DOES NOT matter).

Therefore I believe const should act like class constants, and not like 
define(), as this matches user expectations better.

You can still assign a define()d constant to const, so the argument is kind of 
moot imho. 

See example below:


<?php
namespace foo;

func(); // Warning, and prints "NOT_HOISTED"

define('XXX', 'asdf.'.rand(1,9));

const NOT_HOISTED = XXX;                                                                                                                                                                      

func(); // prints "123"

function func()
{
    echo NOT_HOISTED." ". XXX.PHP_EOL;
}
?>

which yields:

PHP Notice:  Use of undefined constant NOT_HOISTED - assumed 'NOT_HOISTED' in 
b62076.php on line 14
PHP Notice:  Use of undefined constant XXX - assumed 'XXX' in b62076.php on line 
14
NOT_HOISTED XXX
asdf.2 asdf.2