> De : Ryan Pallas [mailto:[email protected]]
>
> With all the new typing and strict mode in PHP7, I'm wondering if there is
> any planned support for typing of properties in a future version. IE
> something like:
>
> class Foo {}
> class Bar {
> public Foo $foo;
>
> public function __construct(Foo $foo) {
> $this->foo = $foo;
> }
> }
>
> This seems really useful to me. If its not something that was considered
> before I can try to write up an RFC for this, however I'm not sure if this
> was already considered and denied. Any feedback would be greatly
> appreciated.
Hi,
I proposed this as an addition to scalar type hinting when we were discussing
the STH RFC some months ago. Zeev and Dmitry, like Rasmus today, thought it was
probably not possible to implement it without huge changes to the engine. After
thinking more about it, I think they're absolutely right. What you want to
implement is not an additional compile-time check, it's attaching type hints to
object properties. That's a runtime check *and* a possible conversion *each*
time a property is assigned. The problem is that the current engine makes it
impossible to trap every zval assignments, let alone the question of
performance. If you look at parameter type hints, argument types are checked
only once, when they are received by the function. Then, in the function body,
you can assign any value/type to every received argument, that's impossible to
check.
Rewriting your example to show the feature has nothing to do with compile-time
checks :
public function __construct(Foo $foo) {
manage($foo);
$this->foo=$foo; /* Compile-time OK, Runtime error */
}
/* In another file, somewhere... */
public function manage(&$obj)
{
...
$obj='bar';
}
Regards
François
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