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Date: Wed, 22 Aug 2012 05:00:29 +0900
Message-ID: <CAGa2bXYpyStxy=XstOiA1HLvx11naWB1kciX08o0kLKcptheEg@mail.gmail.com>
To: Andrew Faulds <ajf@ajf.me>
Cc: Tjerk Anne Meesters <datibbaw@php.net>, Rasmus Schultz <rasmus@mindplay.dk>, internals@lists.php.net
Content-Type: text/plain; charset=ISO-8859-1
Subject: Re: [PHP-DEV] re: removing an item from an array
From: yohgaki@ohgaki.net (Yasuo Ohgaki)

Hi

2012/8/22 Andrew Faulds <ajf@ajf.me>:
> On 21/08/12 10:36, Yasuo Ohgaki wrote:
>>
>> Int would be better and callable should be accepted like array_walk().
>> It's better to have array_delete_recursive(), too.
>> I updated the page.
>
> Callable? What? This is to remove a single value, like a set. If you want to
> remove based on a function, array_walk() is always available. And allowing a
> callable would prevent you from removing closures or strings! D:

Original proposal was to delete all value that matches.
It's not delete a single value.

We could choose to remove only 1st element, but is it useful?
People may do

while (array_delete($array, "do not needed"));

This is stupid O(n^2) code.

>
>>
>> array_add() needs more discussion.
>> What we should do with array value, accept callable or not, etc.
>
> Why accept a callable?
> I don't think it needs more discussion, I can't see how it could be made any
> better than it currently is.

What's the point of adding NEW feature with less extensible against competitor?
Take a look at Ruby's delete_if()

With callable, one could do

$array = [1,2,3,4,5,6,7,8];
$cnt = array_delete($array, function($v) { if ($v <== 4) return true; });
var_dump($cnt, $array); // $cnt = 4, $array = [5,6,7,8]

With array_walk()

$array = [1,2,3,4,5,6,7,8];
$cnt = 0;
array_walk($array, function($v) use (&$array, &$cnt) { if ($v <== 4)
{$cnt++; return true;) });
var_dump($cnt, $array); // $cnt = 4, $array = [5,6,7,8]

As I mentioned earlier, array_walk() is the best way to delete elements with PHP
more than a decade. It should be mentioned the Stack Overflow page,
but it's not.

It's just like adding
array_pop()/array_push()/array_shift()/array_unshift() while
we have array_slice()/array_splice().

Regards,

--
Yasuo Ohgaki
yohgaki@ohgaki.net