Edit report at https://bugs.php.net/bug.php?id=62076&edit=1
ID: 62076
Updated by: f...@php.net
Reported by: phplists at stanvassilev dot com
Summary: Global/namespace constants are not hoisted
-Status: Open
+Status: Wont fix
Type: Bug
Package: Scripting Engine problem
PHP Version: 5.4.3
Block user comment: N
Private report: N
New Comment:
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
Previous Comments:
------------------------------------------------------------------------
[2012-05-20 10:40:18] phplists at stanvassilev dot com
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.
------------------------------------------------------------------------
[2012-05-20 10:28:28] phplists at stanvassilev dot com
Description:
------------
"const" Declarations outside a class were introduced in PHP 5.3, and they only
support static "compile-time" expressions, unlike define().
Function and classes declarations are hoisted to the top of the file, so you
can
call them before the line they are defined in. This doesn't happen
with "const", although it's expected as a matter of consistency. This leads to
the following odd problem:
<?php
namespace foo;
func(); // Warning, and prints "NOT_HOISTED"
const NOT_HOISTED = 123;
func(); // prints "123"
function func()
{
echo NOT_HOISTED;
}
Please make "const" consistent with the rest of the language, and hoist it
together with function and class declarations.
Expected result:
----------------
To print "123" in both cases, no warning.
Actual result:
--------------
Referring to a const before the line it's declared in results in an error and
magical string casting (as if it doesn't exist).
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=62076&edit=1
