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Date: Fri, 10 Oct 2025 10:26:44 -0500
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Subject: Re: [PHP-DEV] [RFC] Partial Function Application v2
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From: larry@garfieldtech.com ("Larry Garfield")

On Thu, Oct 9, 2025, at 4:39 PM, Tim D=C3=BCsterhus wrote:

> I've given it another read. Remarks:
>
>> Positional placeholders that map to the variadic portion of the=20
>> underlying function will be named $args0, $args1, etc., and may be=20
>> called by name if desired.
>
> What will happen if the original function already has a parameter name=
d=20
> $args0?

It will skip over existing names.  I've updated the text accordingly.

>> Prefill all parameters, making a "delayed call" or "thunk"
>
> The example desugaring is inconsistent with the previously explained=20
> semantics: Here an arbitrary number of arguments is accepted, but=20
> previously it says "will result in a Closure with no parameters".

Hm, I think that should probably read "no required parameters".  It woul=
d only make a difference if the underlying function had an optional vari=
adic AND you called the thunk with extra, extraneous args.

*Various typos fixed along the way*

> ------
>
> Questions:
>
> - Are PFAs legal in constant expressions? e.g. does the following work=
:=20
> `const Foo =3D intval(?, 10);`?

At the moment no, though Arnaud says that should be doable, with some re=
asonable restrictions.  (No variables, no variable callable name, etc.)

> - The RFC says that it compiles down to the equivalent Closure. Can yo=
u=20
> add an example of a stack trace for completeness? Ideally one with=20
> SensitiveParameter working. That will then showcase the closure naming=
,=20
> SensitiveParameters and that there are two stack frames for the call.
>
> Best regards
> Tim D=C3=BCsterhus

I've asked Arnaud to generate one for the RFC.

--Larry Garfield