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Date: Tue, 11 Jul 2023 16:04:21 +0200
Message-ID: <CAPzBOBN+Ny9Cfyyjeq2NH1sZqupbbt1HbOdP=cg4A0uxD0Dttg@mail.gmail.com>
To: =?UTF-8?Q?Micha=C5=82_Marcin_Brzuchalski?= <michal.brzuchalski@gmail.com>
Cc: Deleu <deleugyn@gmail.com>, Andreas Heigl <andreas@heigl.org>, internals@lists.php.net
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [PHP-DEV] [VOTE] Interface Default Methods
From: landers.robert@gmail.com (Robert Landers)

> Not exactly, How you wanna solve by abstract class two interfaces
> which can be implemented using let's say two traits - let's say
>
> interface Foo {
>     public function foo(): string;
> }
> trait HasFoo {
>     public function foo(): string { return 'foo'; }
> }
> interface Bar {
>     public function bar(): bool;
> }
> traitHasBar {
>     public function bar(): bool { return true; }
> }
>
> Now I can need to implement Foo or Bar separately or together.
> Using abstract class that would require 3 abstract classes: Foo, Bar, and FooWithBar.
> With this RFC that would require just two interfaces with default methods.

This seems like a software design issue, not a language issue...

But 3 abstract classes vs. 2 interfaces + 2 traits seems like a better
tradeoff if you're going to need the coupling anyway. It's more
obvious that you want/require FooWithBar when you want it. If you're
expecting these exact implementations, moving them to the interface
makes it even more confusing.

I want FooWithBar (iow, I want these exact implementations)

I want Foo&Bar (iow, I don't care about the implementation)

You can pass a FooWithBar to Foo&Bar, but you can't pass a Foo&Bar to
a FooWithBar.

If the default implementation is on the interface ... who knows what
you have, you'll have to check you /vendor folder.