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Date: Wed, 5 Jun 2024 23:39:53 +0200
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Subject: Re: [PHP-DEV] [RFC] Asymmetric Visibility, v2
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From: tovilo.ilija@gmail.com (Ilija Tovilo)

Hi Tim

On Tue, Jun 4, 2024 at 7:54=E2=80=AFPM Tim D=C3=BCsterhus <tim@bastelstu.be=
> wrote:
>
> One thing that would get pretty wonky would be private-read properties:
> Private property names are currently internally "mangled" to include the
> class name. This allows to define the same private property in multiple
> classes of an inheritance chain, without those classes needing to know
> about the private properties of each other and making the addition and
> removal of a private property not a BC break. For all intents and
> purposes those private properties to not exist, unless you are the class
> itself.
>
> I have no idea what the semantics of a public-write, private-read
> property should be - and this problem is pretty similar to the
> sibling-discussion about making private-set properties implicitly final,
> because otherwise the semantics get wonky.
>
> I believe that the case of making a property public-write, private-read
> is best left to a virtual set-only hook.

Indeed. A private property with a more permissible set operation is
the wrong approach. What we'd want here is a public property with a
restricted get operation. This is not quite expressible with the
current syntax. We'd need something like `public private(get)`, or
`public $prop { private get; }` with the C# equivalent. However, this
is quite an edge case, and since it requires additional syntax I don't
think it's something we should support without a specific use-case.
You can emulate it with a set-only virtual property, if you really
want to.

Ilija