Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:85330
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain zort.net designates 96.241.205.2 as permitted sender)
Content-Type: text/plain; charset=windows-1252
Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\))
In-Reply-To: <550C8879.70002@gmail.com>
Date: Fri, 20 Mar 2015 17:04:50 -0400
Cc: internals@lists.php.net
Content-Transfer-Encoding: quoted-printable
Message-ID: <A26C2DC6-9BF0-4A16-A99E-0F72524A73C9@zort.net>
References: <CAAn=CzWySWQU1D93WA7L2eHvd31zogekEHmDUOsN7P6kBK4VrA@mail.gmail.com> <550B5A81.1090706@gmail.com> <550C8879.70002@gmail.com>
To: Stanislav Malyshev <smalyshev@gmail.com>
Subject: Re: [PHP-DEV] RFC - Array slice syntactic sugar
From: jbafford@zort.net (John Bafford)


On Mar 20, 2015, at 16:52, Stanislav Malyshev <smalyshev@gmail.com> =
wrote:

> Hi!
>=20
>>> My proposal is something similar to Pythons slice, in PHP this would =
look
>>> like:
>>>=20
>>> $slided =3D $array[1:4]
>>>=20
>>> This will get the elements in positions 1,2,3,4. (1 through 4 =
inclusive),
>>> ignoring the actual key of the array. The result for an array will =
be an
>>> array with the keys preserved, in the same order.
>=20
> I'm not sure how such operation would be useful, and it definitely =
would
> not be intuitive, as $array[0] and $array[0:1] (assuming non-inclusive
> semantic, or [0:0] with inclusive semantics) would return completely
> different things. That would happen even if the array has only numeric
> keys! This is the main problem with this syntax - unlike most =
languages
> where it is used, PHP arrays are not vectors, they are ordered =
hashmaps.
> Sometimes this is very convenient, sometimes - like for this syntax - =
it
> is not. I think this is the major reason why such proposals failed in
> the past.

My interest in this proposal is mostly because it can potentially =
provide a convenient way to get the first element in an array, which is =
a not-infrequent need of mine.

I provided an array_key_first() implementation awhile ago that was first =
shot down because =93too many array_* functions=94, and then later =
ignored because I didn=92t want to go through the RFC process just to =
add a few functions. (PR here: https://github.com/php/php-src/pull/347)

If people are generally interested in having an =
array_key_(first|last|index) implementation, I can dust off that PR, =
update it for master, and if we really need an RFC, I=92ll prepare one =
for PHP 7.1.

-John