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To: Larry Garfield <larry@garfieldtech.com>, php internals
	<internals@lists.php.net>
Thread-Topic: [PHP-DEV] [RFC] Add is_list(mixed $value): bool to check for
 list-like arrays
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Date: Sun, 20 Dec 2020 20:09:39 +0000
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Subject: Re: [PHP-DEV] [RFC] Add is_list(mixed $value): bool to check for
 list-like arrays
From: tysonandre775@hotmail.com (tyson andre)

Hi Larry Garfield,=0A=
=0A=
> Well, since I'm quoted... :-)=0A=
> =0A=
> I'm fine with this, but have one question and one correction:=0A=
> =0A=
> * If we do eventually end up with list/vec types, would the naming here c=
onflict at all?=A0 Or would it cause confusion and name collision?=A0 (Inse=
rt name bikeshedding here.)=0A=
> =0A=
> * The last quote, from me, has a small error.=A0 The last sentence should=
n't be a bullet point but its own paragraph, after the list is complete.=0A=
=0A=
Yes, there's definitely the potential for naming conflicts if the type is c=
alled `list`=0A=
but not if it's called `vec`/`vector`/`varray` similar to https://docs.hhvm=
.com/hack/built-in-types/arrays - I'd prefer the latter if there was a viab=
le implementation.=0A=
I should note that in the discussion section.=0A=
=0A=
If the type is named `list` instead of `vector` and ends up incompatible wi=
th arrays,=0A=
there'd need to be an `is_list_type($val)` or `$val is list` =0A=
or some other new type check with a less preferable name.=0A=
If it's compatible with arrays/lists =0A=
(e.g. only checked during property assignment, passing in arguments, and re=
turning values), then it wouldn't be an issue.=0A=
=0A=
- is_array_list() or is_array_and_list() or is_values_array() would avoid s=
ome of that ambiguity but would be much more verbose=0A=
=0A=
Providing objects with APIs similar to the external PECL https://www.php.ne=
t/manual/en/class.ds-vector.php and the SPL may be easier to adopt because =
it can be polyfilled,=0A=
but there's the drawback that there aren't the memory savings from copy-on-=
write and that there's the performance overhead of method calls to offsetGe=
t(), etc.=0A=
=0A=
I'd expect the addition of a separate/incompatible vec type to be a massive=
 undertaking, and possibly unpopular if it splits the language.=0A=
In Hack/HHVM, it was practical for users to adopt because HHVM is bundled w=
ith a typechecker that checks that the uses=0A=
are correct at compile time - because PHP has no bundled type checker, a ne=
w type would potentially cause a lot of unintuitive behaviors.=0A=
=0A=
I fixed the formatting of the quote.=0A=
=0A=
-- Tyson=