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Date: Tue, 26 Nov 2013 16:15:42 +0100
Message-ID: <CADcGo3hYoKd074mPeXU5O1TnEXherDYghRQeKcamhXassY9acg@mail.gmail.com>
To: Chris London <me@chrislondon.co>
Cc: "internals@lists.php.net" <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=089e013a009e398e0804ec15f41a
Subject: Re: [PHP-DEV] [Proposal] Modification to ?: functionality
From: mats.lindh@gmail.com (Mats Lindh)

--089e013a009e398e0804ec15f41a
Content-Type: text/plain; charset=ISO-8859-1

On Tue, Nov 26, 2013 at 3:43 PM, Chris London <me@chrislondon.co> wrote:

> I believe these two statements are functionally equivalent:
>
> $foo = $foo ? $foo : 'default';
>
> $foo = $foo ?: 'default';
>

They are.


I would like to change it so it also checks for isset() so I propose the
> following would be functionally equivalent:
>
> $foo = isset($foo) && $foo ? $foo : 'default';
>
> $foo = $foo ?: 'default';
>

The would break the assumption that a reference to an uninitialized value
would generate a notice, unless explicitly handled in the logic.

While I also would like to have something similar to ?: to handle default
values for array keys, etc., this would change a fundamental assumption
that as been in place for many years now. I'm not sure if that's a BC break
that would be acceptable this late. An alternative operator may be more
suitable.

The change proposed has also been discussed several times since the
implementation of ?:. See the ifsetor-RFC:

https://wiki.php.net/rfc/ifsetor

It also contains links to the discussion around the feature back then.

--mats

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