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Date: Tue, 07 Feb 2023 10:30:49 +0000
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Subject: Re: [PHP-DEV] RFC Proposal - Types for Inline Variables
From: me@wendelladriel.com (Wendell Adriel)

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Hey, thanks for the feedback Illia and Hans.



Illia, I think that the main motivation for having the support of typing in=
line variables is that with that we can have more safety in the code.

The code can be more shielded from bugs and easier to maintain.



I don't dislike the idea of having something like const on JS, but I think =
that adding the support to add types to inline variables at least IMO is a =
step further on all the typing that was already added in the language.

We have today the ability to add types to function arguments, return and in=
 class properties. So this is just another step towards adding support to o=
ptional typing on another place.



Types can bring more confidence when writing code, you can see that for exa=
mple a lot of people in the JS community is now using TypeScript because of=
 the types.

I love that PHP already added type support to a lot of places and adding th=
e support for typing inline variables would be a game changer for the langu=
age I think.



Hans, you sent a good example.

I think that in this case, it should throw a TypeError, yes.

I know this would add a lot of breaking changes.

But if we want to avoid some breaking changes we for example make use of th=
e declare(strict_types=3D1) to enforce this if this would means in less bre=
aking changes.



---

Best Regards,

Wendell Adriel.

Software Engineer=C2=A0| Investor | Amateur Photographer | Musician | INFP=
=E2=80=8B


https://wendelladriel.com










---- On Tue, 07 Feb 2023 08:34:07 +0000 Hans Henrik Bergan <divinity76@gmai=
l.com> wrote ---



function f(int $value){=20
 $value=3D"foo"; // should this be a TypeError? BC break all the things=20
}=20
=20
On Mon, 6 Feb 2023 at 22:15, someniatko <mailto:someniatko@gmail.com> wrote=
:=20
>=20
> Hi there,=20
>=20
> I am not a core PHP language developer, just a regular PHP programmer, an=
d=20
> cannot speak for the whole community, so I'll just share my opinion.=20
>=20
> I believe a new language feature suggestion should contain not only its=
=20
> description, but also motivation: i.e. what are we trying to achieve with=
=20
> it. Will the development experience be worse without it, or maybe it=20
> disallows some sneaky bugs to appear in your code, or maybe it acts as a=
=20
> native documentation for your code etc.=20
>=20
> Personally it's hard for me to see what kind of improvement will=20
> restricting a type of a variable bring. It may prevent repurposing the=20
> variable with the same name for a different use somewhere down the=20
> function, which can lead to bugs if a function is large enough. However,=
=20
> for such cases I think better idea would be to introduce `const` variable=
s=20
> like in JavaScript - which can only be set once and cannot be reassigned=
=20
> later. This way you'll also guarantee the type of the variable will be=20
> preserved.=20
>=20
> > We can add types in a lot of places, but we still don't have a way to a=
dd=20
> types to inline variables.=20
>=20
> > int $value =3D 10;=20
> > $value =3D 'foo'; // TypeError=20
>=20
> Can you describe some use cases where this feature will be useful? I see=
=20
> it's coming from statically typed / compiled languages like C++, but in=
=20
> such languages compiler must know variable type in order to manage memory=
=20
> properly. As PHP is an interpreted  language, it doesn't have this proble=
m.=20
>=20
> Regards,=20
> Illia / someniatko=20
=20
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