Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:120682
MIME-Version: 1.0
References: <CAAKU0umNOJ+6x44WRuzc2e9_5sDehAq5UB_aFn+cT4wxTny9wg@mail.gmail.com>
 <CA+p1FaYU58Z7UZuDNEHnOWefZyu6uoP+4iZ7rgOhQHaA+f+_AQ@mail.gmail.com>
 <CAAKU0ukt+rHchFhvcEUJcY8q9UNRjoF9BxQTiWUdOanffg012Q@mail.gmail.com>
 <CA+p1Fabw7We9XQNiSMKo34sZigyjnx6WF1yKXR3Xb66y_o4VYg@mail.gmail.com>
 <a9ee48c8-c1cb-8278-bdc1-22b19fbf15f3@gmail.com> <CA+p1FaZfjuh472ZmUajU46BENet-mPZQM9mBdSb3uJCN0-qRiw@mail.gmail.com>
 <CAFMT4NpPcciDmp5JNjeAzFYncEc9+7U3m4wabU85CHD2xRHFjw@mail.gmail.com>
 <CA+p1FabbzRLLBet_-3LzV5K6fA4Endbwmki7KjiWjQcue5wzgQ@mail.gmail.com> <CAFMT4NpkASAgwRoKsz7jLAQBY614fg7W4fP_jRJ8HBMBZJBn0A@mail.gmail.com>
In-Reply-To: <CAFMT4NpkASAgwRoKsz7jLAQBY614fg7W4fP_jRJ8HBMBZJBn0A@mail.gmail.com>
Reply-To: Levi Morrison <levi.morrison@datadoghq.com>
Date: Mon, 26 Jun 2023 09:43:46 -0600
Message-ID: <CAAKU0unFfbfq0NYA39t6yf9Y0BsszqKtF2Y0iY2KjaNybT2fSw@mail.gmail.com>
To: Levi Morrison <levim@php.net>
Cc: David Gebler <davidgebler@gmail.com>, PHP internals <internals@lists.php.net>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Subject: Re: [PHP-DEV] [RFC] Interface Default Methods
From: internals@lists.php.net ("Levi Morrison via internals")

On Tue, Jun 20, 2023 at 9:46=E2=80=AFPM Levi Morrison <levim@php.net> wrote=
:
>
> On Tue, Jun 20, 2023 at 6:29=E2=80=AFAM David Gebler <davidgebler@gmail.c=
om> wrote:
> >
> > On Tue, 20 Jun 2023, 04:10 Levi Morrison, <levim@php.net> wrote:
> >
> > > > I like the idea of this RFC - in fact it's one which has been near =
top of
> > > > my wishlist for PHP language features for a long time - but I think=
 this
> > > is
> > > > an issue with the proposed implementation which at the very least
> > > warrants
> > > > highlighting and discussion.
> > >
> > > I understand your concern but personally believe it's overblown. This
> > > problem already exists with abstract classes, but doesn't seem to be
> > > that much of an issue in practice. I hope static analysis can fill th=
e
> > > gap here, but don't think these checks are necessary to ship this
> > > feature.
> > >
> >
> >
> > Yeah I suppose I'm just saying "Interface default methods" can be
> > interpreted a few different ways and there's key differences between
> > Java-style, versus syntax sugar for mixing an interface and a trait in =
to
> > one unit, versus a user can effectively extend multiple abstract classe=
s
> > but with interface keyword.
>
> I will update the RFC soon. In my head it was so obvious that it would
> be similar to regular inheritance and less like traits, to the extent
> I didn't even realize I'd need to specify it. This is why discussion
> periods can be valuable; the RFC doesn't always say what's in the RFC
> author's head :)


I have significantly updated the RFC. There's one more topic that
needs to go in there, tentatively called 'default cancelling':

```php
interface Interface1 { function m1() { /* ... */ } }
interface Interface2 extends Interface1 {
    function m1(); // may or may not change signature
}
```

For various reasons which I'll put in the RFC, this will "cancel" the
default, meaning any class which implements Interface2 instead of
Interface1 will not receive that default.