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Date: Fri, 17 Oct 2025 10:10:46 +0200
To: Larry Garfield <larry@garfieldtech.com>
Cc: php internals <internals@lists.php.net>
Subject: Re: [PHP-DEV] [RFC] Partial Function Application v2
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From: tim@bastelstu.be (=?UTF-8?Q?Tim_D=C3=BCsterhus?=)

Hi

Am 2025-10-13 20:23, schrieb Larry Garfield:
> OK, there was a miscommunication between Arnaud and I.  It is using the 
> variable name, not "args" already.  Just with no _ and 0-based.  I've 
> updated the RFC accordingly.

Thank you! I noticed a small typo in one of the updated examples:

$c = fn(int $i1, ?float $f3, Point $points0, Point $points`): string => 
things($i1, $f3, $points0, $points1);

The second points parameter is misnamed.

> We talked a bit more, and decided to tighten the rules further.  I've 
> updated the RFC accordingly.  Essentially, the first example is 
> correct, the second has been changed.
> 
> If the underlying function is variadic, and ... is used in the PFA, 
> then it will accept an arbitrary number of arguments.  In any other 
> case, only explicitly-specified arguments will be passed through.

The RFC still says:

// Whereas strictly speaking, a variadic placeholder is equivalent to 
this:
$f = foo(1, ...);
$f = fn(int $b, int $c): int => foo(1, $b, $c, $d, 
...array_slice(func_get_args(), 3));

Did you miss updating that? This also makes me realize that this means 
that PFA will not actually be a strict superset of FCC, no? FCC always 
passes through all the extra arguments, whereas PFA will not (at least 
based on your reply).

Best regards
Tim Düsterhus