On 26/08/2024 08:28, Rowan Tommins [IMSoP] wrote:
As far as I can see, nobody has actually justified reading values out in this way, only said it's a side-effect of the current implementation.
It's pretty useful for testing.
Aside: one of those examples brings up an interesting question: is the value pulled out by "default" calculated only once, or each time it's mentioned? In other words, would this create 3 pointers to the same object, or 3 different objects?
foo(array|Something $x=new Something);
foo([default, default, default]);
Thanks for this interesting question. Here is the output from your (slightly modified) script:
class Something {}
function foo(array|Something $x=new Something) {return $x;}
var_dump($x = foo([default, default, default]));
var_dump($x[0] === $x[1]);
array(3) {
[0]=>
object(Something)#1 (0) {
}
[1]=>
object(Something)#2 (0) {
}
[2]=>
object(Something)#3 (0) {
}
}
bool(false)
As you can observe from the object hashes, each object is unique. That is, we fetch the default value each time the keyword appears, which in the case of objects, creates a new instance each time. I will update the RFC with this information.
Cheers,
Bilge