On Mon, 24 Feb 2025 at 14:45, Nicolas Grekas <nicolas.grekas+...@gmail.com> wrote:
> > > Am 2025-02-24 12:08, schrieb Nicolas Grekas: >> > The situation I'm telling about is when one will accept an argument >> > described as >> > function (\Uri\WhatWg\Url $url) >> > >> > If the Url class is final, this signature means only one possible >> > implementation can ever be passed: the native one. Composition cannot >> > be >> > achieve because there's no type to compose. >> >> Yes, that's the point: The behavior and the type are intimately tied >> together. The Uri/Url classes are representing values, not services. You >> wouldn't extend an int either. For DateTimeImmutable inheritance being >> legal causes a ton of needless bugs (especially around serialization >> behavior). >> > > DatetimeImmutable is a good example of community-proven usefulness for > inheritance: > the carbon package has a huge success because it does add a ton of nice > helpers (that are better maintained in userland) while still providing > compatibility with functions that accept the native type. > > The fact that the native implementation had bugs when inheritance was used > doesn't mean inheritance is a problem. It's just bugs that need to be > fixed. Conceptually nothing makes those bugs inevitable. > > Closing the class would have hindered community-innovation. The same > applies here. > > TBH, data-point from someone that spends time removing Carbon usages here :-P The `DateTimeImmutable` type should've been `final` from the start: it is trivial to declare a userland interface, and then use the `DateTimeImmutable` type as an implementation detail of a userland-provided interface. PSR-7, for example, will benefit greatly from this new RFC, without ever having to expose the underlying value type to userland. Inheritance is a tool to be used when there is LSP-compliant divergence from the original type, and here, the PHP RFC aims at modeling something that doesn't have alternative implementations: it's closed for modification, and that's good. Marco Pivetta https://mastodon.social/@ocramius https://ocramius.github.io/
