Add func_get_named_args()

[alexandre-daubois]

I'm not entirely sure this would require a RFC. That's why I'm proposing this PR first, and I'll gladly write an RFC if someone requires it.

Allows to write the following code:

<?php

function hello(string $name, int $age, ...$args): array {
  return func_get_named_args();
}

var_dump(hello('World', 30, 'extra1', 'extra2'));

Output:

array(4) {
  ["name"]=>
  string(5) "World"
  ["age"]=>
  int(30)
  [2]=>
  string(6) "extra1"
  [3]=>
  string(6) "extra2"
}

I think this would be a nice addition. With named arguments being more and more popular and the possibility to leverage arrays spreading operator, adding this function feels natural. There's no easy way to do so currently without using reflection.

They differ a bit on they behavior with spread operator and variadic argument:

function hello(string $name, int $age, ...$args): array {
  return func_get_args();
}

var_dump(hello(...[
    'age' => 30,
    'name' => 'John',
    'extra' => 'data',
]));

/*
array(2) {
  [0]=>
  string(4) "John"
  [1]=>
  int(30)
}

-> 'extra' is missing in this output
*/

function hello_named(string $name, int $age, ...$args): array {
  return func_get_named_args();
}

var_dump(hello_named(...[
    'age' => 30,
    'name' => 'John',
    'extra' => 'data',
]));

/*
array(3) {
  ["name"]=>
  string(4) "John"
  ["age"]=>
  int(30)
  ["extra"]=>
  string(4) "data"
}
*/

Adding this function instead of updating func_get_args() seems better to me, which avoids any breaking change.

[iluuu1994]

Not too much of a fan of further expanding this kind of argument handling, but just my personal opinion. The name sounds a bit ambiguous due to "named args", makes it sound like only arguments that were passed by name would be returned. Maybe func_get_args_by_name() would be less ambiguous.

[alexandre-daubois]

An additional use case is that we often use this args handling in Symfony to add new args to methods without breaking backward compatibility between minor versions.

About the naming: your proposition would also suit me fine.

[nielsdos]

Slightly related to #11517 (patch also included)

[NickSdot]

I'd love to see this!