Type hints revisited [IllegalArgumentException instead of E_ERROR] View as Markdown

At 05:16 PM 3/27/2003 +0100, Timm Friebe wrote:

I've implemented an additional feature for type hints that will throw an
exception instead of bailing out in case an incorrect type is passed.

I don't see any major advantage in doing this. I think we should keep PHP
error handling the same as in PHP 4 and leave exceptions in user-land.
Otherwise we'll end up having an unmanageable hybrid because there's no way
we're going to change the error-handling of the existing internal
functions. The majority of our user base is still functional, please don't
forget this. I feel that people here tend to forget that.

Andi

Test script:

<?php
class Date { }
class Article {
public function setCreated_at(Date $date) {
echo CLASS, '::', FUNCTION, ' called with ';
var_export($date);
echo "\n";
}

public function setLastchange([Date] $date) {
  echo __CLASS__, '::', __FUNCTION__, ' called with ';
  var_export($date);
  echo "\n";
}

}

$a= new Article();
$a->setLastchange(new Date());
$a->setLastchange(NULL); // Passes
$a->setCreated_at(new Date());

try {
$a->setCreated_at(NULL); // Fails
} catch (IllegalArgumentException $e) {
echo "Caught: "; var_dump($e);
}

$a->setCreated_at(1); // Fails
echo "Alive"; // Will not show up
?>

Output:

thekid@friebes:~/devel/php > ./php5/sapi/cli/php hints.php
article::setlastchange called with class date {
}
article::setlastchange called with NULL
article::setcreated_at called with class date {
}
Caught: object(illegalargumentexception)#2 (3) {
["message"]=>
string(38) "Argument 1 must be an instance of date"
["file"]=>
string(36) "/usr/home/thekid/devel/php/hints.php"
["line"]=>
int(4)
}

Fatal error: Uncaught exception! in Unknown on line 0

A unified diff is attached.

• Timm

Has type hinting for functions been implemented in ZE2?

Brian.
dealnews.com

----- Original Message -----
From: "Timm Friebe" thekid@thekid.de
To: engine2@lists.zend.com
Cc: internals@lists.php.net
Sent: Thursday, March 27, 2003 10:16 AM
Subject: [PHP-DEV] Type hints revisited [IllegalArgumentException instead of
E_ERROR]

| I've implemented an additional feature for type hints that will throw an
| exception instead of bailing out in case an incorrect type is passed.
|
| Test script:
|
| <?php
| class Date { }
| class Article {
| public function setCreated_at(Date $date) {
| echo CLASS, '::', FUNCTION, ' called with ';
| var_export($date);
| echo "\n";
| }
|
| public function setLastchange([Date] $date) {
| echo CLASS, '::', FUNCTION, ' called with ';
| var_export($date);
| echo "\n";
| }
| }
|
| $a= new Article();
| $a->setLastchange(new Date());
| $a->setLastchange(NULL); // Passes
| $a->setCreated_at(new Date());
|
| try {
| $a->setCreated_at(NULL); // Fails
| } catch (IllegalArgumentException $e) {
| echo "Caught: "; var_dump($e);
| }
|
| $a->setCreated_at(1); // Fails
| echo "Alive"; // Will not show up
| ?>
|
| Output:
| ---------------------------------------------------------------------
| thekid@friebes:~/devel/php > ./php5/sapi/cli/php hints.php
| article::setlastchange called with class date {
| }
| article::setlastchange called with NULL
| article::setcreated_at called with class date {
| }
| Caught: object(illegalargumentexception)#2 (3) {
| ["message"]=>
| string(38) "Argument 1 must be an instance of date"
| ["file"]=>
| string(36) "/usr/home/thekid/devel/php/hints.php"
| ["line"]=>
| int(4)
| }
|
| Fatal error: Uncaught exception! in Unknown on line 0
| ---------------------------------------------------------------------
|
| A unified diff is attached.
|
| - Timm
|

| --
|
|

I've implemented an additional feature for type hints that will throw an
exception instead of bailing out in case an incorrect type is passed.
[...LONG disussion...]

After reading through a bunch of mails this generated, I get the idea
that most people here would be happier with an E_WARNING and the
function not being executed.

That gives:

• the OOP purist the possibility to throw an exception (in a userland
  error handler)
• the SOAP server a way to nicely recover
• the API designer a way to tell the user (s)he's messed up
• the "standard" programmer what (s)he's used to (PHP is quite
  forgiving in the way it handles incorrect argument types and
  usually warns about this)

Attached is the E_WARNING variant, an example script and its output.

• Timm

At 07:15 29/03/2003, Timm Friebe wrote:

I've implemented an additional feature for type hints that will throw an
exception instead of bailing out in case an incorrect type is passed.
[...LONG disussion...]

After reading through a bunch of mails this generated, I get the idea
that most people here would be happier with an E_WARNING and the
function not being executed.

?!

How the heck can we even think about such a thing? When you call a
function, you expect it to run. The code that follows it may rely on stuff
that it has done. Not running it is simply not an option, I can't even
begin to imagine the possible consequences of such an approach!

Type hints are shortcuts for instanceof. If you want to handle a situation
where the function is passed the wrong arguments, don't use type hints, use
instanceof. Or use the errors-for-exceptions mode that we may have.

Zeev