hi Joe,

No problem, great it's fixed before 7.0.6 release.

I think this change might be introduced only together with nullable or union 
types.

Otherwise it makes a problem, described by Levi, that doesn't allow running the 
same code in PHP-7.0 and 7.1, and even doesn't allow an ease fix.


Thanks. Dmitry.


________________________________
From: Joe Watkins <pthre...@pthreads.org>
Sent: Thursday, April 28, 2016 8:20:12 PM
To: Dmitry Stogov
Cc: Levi Morrison; internals; Tom Worster
Subject: Re: Request to withdraw RFC's for nullable types for only return values

Evening Dmitry,

This was discussed at length with bob, and I think nikita also, it seemed like 
a bug fix rather than a feature.

Happy for it to be moved into 7.1 ... sorry for dropping the ball there ...

Cheers
Joe

On Thu, Apr 28, 2016 at 6:07 PM, Dmitry Stogov 
<dmi...@zend.com<mailto:dmi...@zend.com>> wrote:
Thanks for catching the BC break.
Fortunately, we didn't release 7.0.6 with this problem.

I see some sense in introducing that check, but changing behaviour requires RFC 
and definitely not allowed in minor versions.

I'm not going to withdraw https://wiki.php.net/rfc/nullable_return_types
It doesn't prohibit usage of nullable for arguments, and even sets additional 
question.

Thanks. Dmitry.

________________________________________
From: morrison.l...@gmail.com<mailto:morrison.l...@gmail.com> 
<morrison.l...@gmail.com<mailto:morrison.l...@gmail.com>> on behalf of Levi 
Morrison <le...@php.net<mailto:le...@php.net>>
Sent: Thursday, April 28, 2016 6:40:59 PM
To: internals
Cc: Dmitry Stogov; Tom Worster
Subject: Request to withdraw RFC's for nullable types for only return values

I have discovered through a [bug report][1] a case where having
explicitly nullable parameters would be of value.

<?php

interface Foo {
    public function bar(array $baz = null);
}

class Hello implements Foo {
    public function bar(array $baz = array())  {}
}

?>

You can theoretically change the default value in a sub-type, but in
this case moving away from the default value of null breaks because
the subtype no longer permits null. It is important to realize that we
previously *allowed* this behavior since PHP 5.1 but was fixed in
7.0.6.

If instead we had nullable types separately from default values of
null this could change to:

<?php

class Hello implements Foo {
    public function bar(array | null $baz = [])  {}
}

?>

(or a short-form `?array $baz = []` if short-form passes)

This preserves the ability to be null but changes the default value.
Of course, there may be other code changes necessary to future-proof
their code but there current code would now work without having to
rewrite any method bodies (just signatures).

In light of this I kindly request that RFCs that add nullable types
for only return values be withdrawn. So that [Union Types][2] and
[Nullable Types][3] can go forward unhindered.


  [1]: https://bugs.php.net/bug.php?id=72119
  [2]: https://wiki.php.net/rfc/union_types
  [2]: https://wiki.php.net/rfc/nullable_types

Reply via email to