Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:91047
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: unknown (pb1.pair.com: domain php.net does not designate 212.27.42.2 as permitted sender)
To: Stanislav Malyshev <smalyshev@gmail.com>,
 Nikita Popov <nikita.ppv@gmail.com>
References: <56A3A01F.1020500@php.net>
 <CAF+90c-rh5uss4xTjbvvjr6PO5iAYaQ=DQRbVNr+h1kMm8HW9A@mail.gmail.com>
 <56AE8735.4070901@gmail.com>
Cc: Internals <internals@lists.php.net>
Message-ID: <56AF9426.5070107@php.net>
Date: Mon, 1 Feb 2016 18:21:42 +0100
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101
 Thunderbird/38.5.1
MIME-Version: 1.0
In-Reply-To: <56AE8735.4070901@gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Subject: Re: [PHP-DEV] [RFC] Generalize support of negative string offsets
From: francois@php.net (=?UTF-8?Q?Fran=c3=a7ois_Laupretre?=)

Le 31/01/2016 23:14, Stanislav Malyshev a écrit :
> Hi!
>
>> The only concern I have is that support of negative indexing will break
>> symmetry with (proper) arrays, where we cannot support negative indexing.
>
> I think that was the main source of objections to this proposal in the
> past. However, as one might say, string offsets are already not
> symmetrical to array offsets - e.g. you can do $array["foo"] but not
> $string["foo"].
>
>> However this is unlikely to be a significant issue. (I do however play with
>> the thought of reutilizing the obsolete {} indexing syntax to act as offset
>> indexing instead.)
>
> I think it may be a good idea to start recommending using {} for string
> offsets and [] for arrays. While both syntaxes may work for strings, the
> intent (and expected handling of negatives, in this case) is much
> clearer when different syntax is used.
>

Yes, authorizing array-related '[]' syntax on strings may look fine at 
first sight, but it only brings some unwanted ambiguity for no real 
benefit. And ambiguity increases with the support of negative string 
offsets.

So, I just added a chapter to the RFC, saying that documentation would 
be modified to recommend using the '{}' syntax for string offsets.

Regards

François