Edit report at http://bugs.php.net/bug.php?id=51280&edit=1
ID: 51280
Comment by: olamedia at gmail dot com
Reported by: olamedia at gmail dot com
Summary: Calculate expression before using it as argument
Status: Bogus
Type: Feature/Change Request
Package: *General Issues
PHP Version: 5.3.2
New Comment:
Precalculation can be useful for ORM, for example, giving ability to use
this
construction:
$users->where($group->id = 2)
Also, this can be used for named parameters emulation:
class parameter{
var $name;
var $value;
function __construct($name, $value){
$this->name = $name;
$this->value = $value;
}
}
class parameters{
var $data = array();
function __set($name, $value){
$this->data[$name] = new parameter($name, $value);
}
function __get($name){
return $this->data[$name];
}
}
function a(){
var_dump(func_get_args());
}
$arg = new parameters();
a($arg->id = 3, $arg->x = 'some', $arg->y = 5);
Previous Comments:
------------------------------------------------------------------------
[2010-03-22 10:18:40] johan...@php.net
The order of the evaluation of function parameters is "undefined". (It
actually changed with 5.2 or so due to performance reasons)
------------------------------------------------------------------------
[2010-03-22 09:51:47] olamedia at gmail dot com
Sorry, my bad. This was an incomplete example. In first message there
was a good
example, when $a->x is an object, and in both cases: a($a->x) and
a($a->x = 3) - I
'm expecting object $a->x instead of assigned value because of __set()
function,
which converts value to an object.
------------------------------------------------------------------------
[2010-03-22 09:43:51] olamedia at gmail dot com
> the value of "$a = 3" is 3
Here I'm talking about function arguments, not a simple assignments.
function b($a){
// here expected resulting object $a, not just int(3)
var_dump($a);
}
class a{}
$a = new a();
b($a->x = 3); // outputs int(3)
$a->x = 3
b($a); // outputs object(a)#2 (1) { ["x"]=> int(3) }
------------------------------------------------------------------------
[2010-03-21 21:07:08] hholz...@php.net
Expected behavior, see:
http://php.net/manual/en/language.operators.assignment.php
[...]
The value of an assignment expression is the value assigned.
That is, the value of "$a = 3" is 3.
[...]
------------------------------------------------------------------------
[2010-03-12 08:45:19] olamedia at gmail dot com
Description:
------------
Calculate expression before using it as argument in function and with
echo.
Test script:
---------------
class p{
protected $_name = null;
protected $_value = null;
public function __construct($name, $value){
$this->_name = $name;
$this->_value = $value;
}
public function is($value){
$this->_value = $value;
return $this;
}
public function __toString(){
return "$this->_name = $this->_value";
}
}
class a{
protected $_a = null;
public function __set($name, $value){
$this->_a[$name] = new p($name, $value);
return $this->_a[$name];
}
public function __get($name){
if (!isset($this->_a[$name])){
$this->_a[$name] = new p($name, null);
}
return $this->_a[$name];
}
}
class q{
public function where($var){
echo $var;
}
}
$a = new a();
echo $a->x = 2; // "2" (Expected: "x = 2")
echo "\r\n";
echo $a->x; // "x = 2"
echo "\r\n";
$q = new q();
$q->where($a->x = 2); // "2" (Expected: "x = 2")
echo "\r\n";
$q->where(($a->x = 2)); // "2" (Expected: "x = 2")
Expected result:
----------------
x = 2
x = 2
x = 2
x = 2
Actual result:
--------------
2
x = 2
2
2
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/bug.php?id=51280&edit=1
