Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:127080
Message-ID: <0f9bf0ec-6bf4-4ee2-8683-b774085136f5@gmail.com>
Date: Wed, 9 Apr 2025 00:26:31 +0200
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PHP-DEV] [RFC] [Discussion] array_first() and array_last()
To: PHP internals <internals@lists.php.net>
References: <51fcec92-b2ae-482e-920f-c6c991b526c5@gmail.com>
 <62C3AAC4-0D41-470B-AB26-8FC92B59E0EF@gmail.com>
Content-Language: en-US
In-Reply-To: <62C3AAC4-0D41-470B-AB26-8FC92B59E0EF@gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: dossche.niels@gmail.com (Niels Dossche)

On 4/8/25 8:46 PM, Claude Pache wrote:
> Hi,
> 
> I think that this argument is not convincing, and even counterproductive:
> 
> * NULL is a rare legitimate value, so the potential for clashing is low
> 
> First, it says that it is a “rare” legitimate value, which one can disagree with. (I do disagree.)
> 

I think it's a matter of phrasing, but I agree that it can be more nuanced.

> Second, the way it is formulated, it implies that, when `null` is used in array, there will be “clashing”, which is not necessarily the case. (I consider that there is almost never a clash, because it is rarely useful to make the difference between an explicit `null` and a missing value, and, when it is useful, you have almost surely already checked for an empty array upfront.)
> 
> I suggest to replace that argument with the two following ones, that doesn’t treat arrays with NULL as second class citizens:
> 
> * Semantically, NULL represents a missing value. Returning NULL from an empty array is not semantically incorrect, but it means that the function doesn’t differentiate between a implicit missing value (empty array) and an explicit missing value (array with NULL as its first/last element).
> 
> * In the relatively rare cases you do want to make the difference between an empty array and an array that starts/ends with NULL, you can (and should) just check for empty array upfront.
> 

That's indeed a bit better worded and more nuanced. I might adapt the RFC text a bit; although in the end it kinda means the same thing anyway.

> -------
> 
> One more thing. On https://www.php.net/, I read: “Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world.” (emphasis added). If we were to design some new perfect language, we might consider making `array_first()` (or equivalent) choke on empty arrays. But given the current state of the affairs, the pragmatic thing to do is to pave the cowpath.

I agree. I value consistency; we have too much inconsistency already in PHP anyway, let's not add more (unless we would have a very very good reason to do so; but that's not in this case IMO).