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Date: Mon, 31 Oct 2016 08:25:56 +0900
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To: "internals@lists.php.net" <internals@lists.php.net>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [PHP-DEV] Allow Iterator to be used with current, next, reset,
 key functions
From: yohgaki@ohgaki.net (Yasuo Ohgaki)

Hi, Fleshgrinder


On Mon, Oct 31, 2016 at 8:10 AM, Fleshgrinder <php@fleshgrinder.com> wrote:
> On 10/30/2016 11:59 PM, Yasuo Ohgaki wrote:
>> There should be delete option. It's more useful if there is this option.
>>
>> mixed array_first(array $arr [,bool $get_key = FALSE [, bool
>> $remove_entry=FALSE]]);
>> mixed array_last(array $arr [,bool $get_key = FALSE [, bool
>> $remove_entry=FALSE]]);
>>
>> Problem with this is error condition. When array is empty, what should
>> be returned from these with default option?  Returning NULL for empty
>> array would be enough. IMO.
>>
>
> Flags are usually a bad design decision, it's better to make it fully
> explicit and provide dedicated APIs for everything. This is much easier
> for the reader and reading is more important than anything else.

It depends. Defining specific functions for a task could be bad design
also. We do design basic functions with flags usually, too.

That said, dedicated functions for getting first/last key/value sounds
good to me.

>
> ```
> /** Get the first element in the array. */
> function array_first(array $array);
>
> /** Get the key of the first element in the array. */
> function array_first_key(array $array);
>
> /** Get the last element in the array. */
> function array_last(array $array);
>
> /** Get the key of the last element in the array. */
> function array_last_key(array $array);
>
> /** Get and remove the first element from the array. */
> function array_take_first(array $array);
>
> /** Get the key of the first element in the array and remove it. */
> function array_take_first_key(array $array);
>
> /** Get and remove the last element from the array. */
> function array_take_last(array $array);
>
> /** Get the key of the last element in the array and remove it. */
> function array_take_last_key(array $array);
> ```
>
> Returning `null` is imho the most sensible thing we can do if the array
> is empty.

A agree. That's the reason why I state return value is problem. However,

if (empty($arr)) {
  // Do something
} else {
  $first = array_first($arr);
}

shouldn't be difficult.

We should raise error for nonsense usage. Programmers have to check
empty()/isset() all the time anyway.

Regards,

--
Yasuo Ohgaki
yohgaki@ohgaki.net