On Mon, Sep 5, 2022 at 9:57 AM Nicolas Grekas <nicolas.grekas+...@gmail.com> wrote: > > >Hi Marco, > > > > > >IMO good as-is: can be relaxed later (8.3 or later), if anybody believes > > >> it's a show-stopper. > > >> > > >Readonly classes don't really need to be lazy. > > >> > > > > > >"Break things and move slow" doesn't feel right to me for the language. > > > > It's a new keyword that you have to opt into. So it's not breaking > > anything. It just means you might not be able to use it for your use case > > yet. > > > > (and before you say that third party code might add it, you can just say > > you don't support it yet). > > > > It's not like it wouldn't be supported *yet*. It won't be supported *by > design of the language*. > > Readonly classes introduce a new concept that isn't backed by any language > theory I've read about. > Of course it doesn't break until you use it, but conceptually, it breaks a > universal design pattern: inheritance-based proxy decorators. > What I'm asking for is: what is the justification for this limitation? If > there is none, we should drop it. Preemptively breaking universal concepts > (decoration) by introducing a never-seen concept might be innovation for > sure. Or it might be a mistake. E.g. do we know any other language that > provides something like readonly classes? How do they deal with inheritance? > Can anyone answer those questions? > > If we come to the conclusion that there is no backing theory to support > propagating the readonly flag to child classes, then we might decide if we > want to fix this in 8.2 or 8.3. I know I would prefer acting in 8.2, but > that's a separate discussion. > > Nicolas
> do we know any other language that provides something like readonly classes? > How do they deal with inheritance? C# has readonly structs, but inheritance isn't allowed with structs so they slightly side-step this problem. (https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/struct#readonly-struct) They also have "records" which are immutable class-like objects with language support for cloning using `with().` https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/record ... these "records" can inherit from each other, but a regular class cannot inherit from a record and vice-versa. Robert Landers Software Engineer Utrecht NL -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
