[RFC] Implement scalar extensions (WIP)

[iluuu1994]

RFC draft: https://github.com/iluuu1994/scalar-extensions-rfc/pull/1/files
Based on https://github.com/nikic/scalar_objects

• Allow passing self by reference
• Multiple handlers
• Dump extensions in opcache dumper
• Get rid of extension keyword BC break
• Restruct use extension to top of file
• Implement __callStatic
• Clean up VM
• Provide basic standard library?

[HallofFamer]

Its an interesting idea, though I suggest bringing it to PECL first? I cant do this myself, and Nikita does seem to be interested in hosting it on PECL either. Maybe someone else can make this happen.

Anyway I think we can expand the idea into for not just scalars, but also classes. I feel that the approach is very similar to C#'s extension methods, using static methods and passing the value as the first argument in these methods:

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/classes-and-structs/extension-methods

[iluuu1994]

We're probably gonna take a different approach and implement a fixed API for scalar values.

[JWprogrammer]

Hi.
Thank you for your hard work in developing PHP.
@iluuu1994, is there any progress on this issue?
It's very inconvenient to write like this: trim(strrev(str_replace('_', '-', $string)));
$string->replace('_', '-')->reverse()->trim(); is much better.
Thank you