On 21/10/2024 14:20, Gina P. Banyard wrote:
This RFC does*NOT* change the by-ref parameter passing*NOR* the in-place sorting of these functions.
I don't see why people are thinking this would be changed, as I only ever talk about the return value.
But I added a sentence in the Unaffected PHP Functionality section.
I think maybe people are saying that the RFC *should* aim to do that, in some form.
I absolutely agree that the current design is unfortunate; but I worry that bugs will be introduced by people not realising that the function both modifies and returns its argument.
Take the classic example of why DateTimeImmutable exists:
$now = new DateTime;
$tomorrow = $now->modify('+1 day');
// $tomorrow has the expected value, but $now does not
And then compare to the proposed behaviour of sort():
$names_as_entered = explode(',', $_POST['names']);
$names_sorted = sort($names_as_entered);
// oops, we just lost our original order
If someone wants to write that code (i.e. make a sorted copy), they'd need to force a clone on the array somehow, e.g.
$names_as_entered = explode(',', $_POST['names']);
$names_sorted = sort(iterator_to_array($names_as_entered));
Which is probably less clear than the existing version:
$names_as_entered = explode(',', $_POST['names']);
$names_sorted = $names_as_entered;
sort($names_sorted);
The same bug can easily hide inside less obviously imperative code. This would remove the highest 10 numbers from a list, leaving others untouched:
$result = array_filter(
array: $data,
callback: fn($item) => !in_array($item, array_slice(rsort($data, SORT_NUMERIC), 0, 10))
);
This looks like a safe refactor for performance or readability, but would lose the original keys and order:
$top_10 = array_slice(rsort($data, SORT_NUMERIC), 0, 10);
$result = array_filter(
array: $data,
callback: fn($item) => !in_array($item, $top_10)
);
[Here's a demo: Online PHP editor | output for 9Nieo For anyone confused by this example, the first version works because the fn() closure captures $data by-value, effectively cloning it.]
Regards,
--
Rowan Tommins
[IMSoP]