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Date: Mon, 20 Aug 2012 12:05:42 -0600
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To: Andrew Faulds <ajf@ajf.me>
Cc: Herman Radtke <hermanradtke@gmail.com>, Yasuo Ohgaki <yohgaki@ohgaki.net>, 
	Etienne Kneuss <colder@php.net>, Rasmus Lerdorf <rasmus@lerdorf.com>, 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: morrison.levi@gmail.com (Levi Morrison)

Some major points to consider for `array_delete`'s behavior:

1. Should items be compared with `==`, `===`, or custom comparison? If
we use `==` or `===` we'd probably add `array_udelete` to allow a
custom comparator.
2. Should it stop when it encounters the first value that matches?  If
it does, should we add a function that searches in the reverse
direction?
3. Should it modify the array in-place? If so, should we have another
function that returns a copy of the array that does not include the
removed value(s) instead?

If someone wants to go through and define all of these cases and
propose a patch, more power to them.

-----

Here are some reasons that aren't related to the above as to why I'm
against adding `array_delete`:

1. PHP arrays are not sets. PHP arrays are meant to be a list and an
associative array. As such, a PHP array can act as any* data structure
that can be built from a list or associative array.  A data structure
that removes something by value is typically associated with a set and
therefore does not belong in an array.
2. Using other array functions cover this use case AND do a better
job.  Want to remove the first instance of the value? Use
`array_search` to find the index and unset it. If you want to reorder
the array you can use `array_search` to find the index and use
`array_slice`.  Want to remove all instances of the value in the
array? Use `array_filter`.