The "pipe operator"
|> allows you to chain multiple function calls in a more convenient way.
This RFC proposes a way to have multi-line short closures — closures that don't need explicit
use statements, but can still have multiple lines and a return statement.
Interface Default Methods improves backwards compatibility when changing interfaces, but also add a way to have multi-inheritance in PHP.
As written this feels too close to multiple inheritance. We already have traits. Why not allow an interface to reference a trait as the default implementation and then allow a class to optionally use that trait through the interface reference.