Add new flag ARRAY_FILTER_PACK_RESULT

[DanielEScherzer]

No description provided.

[DanielEScherzer]

Requested by someone at PHPTek and seemed pretty simple to implement
Our current documentation notes that

Array keys are preserved, and may result in gaps if the array was indexed. The result array can be reindexed using the array_values() function.

This would eliminate the need for an extra method call and improve performance

Plenty of existing code would use this: https://github.com/search?q=language%3Aphp%20-is%3Afork%20-is%3Aarchived%20%2F%5C%5C%3Farray_values%5C(%5Cs*%5C%5C%3Farray_filter%2F&type=code

let me know if an RFC is needed, not sure if this is small enough or not

[alecpl]

Excuse my ignorance. Isn't technicly [12 => 'bar', 42 => 'baz'] array a "packed array"? array_values() "returns an indexed array of values", as the docs say.

Wouldn't ARRAY_FILTER_REINDEX make more sense?

[jorgsowa]

I was working on this topic in the past, and there are already some opinions about the proper direction. #18291

It would require discussion on the internals about the clear and consistent direction.

I would be happy for the list_* family functions for packed arrays.

[DanielEScherzer]

Excuse my ignorance. Isn't technicly [12 => 'bar', 42 => 'baz'] array a "packed array"? array_values() "returns an indexed array of values", as the docs say.

Wouldn't ARRAY_FILTER_REINDEX make more sense?

A packed array is one with consecutive integer indexes, basically an array that would pass https://www.php.net/manual/en/function.array-is-list.php - see

php-src/Zend/zend_hash.h

Lines 1612 to 1615 in 9898293

	if (HT_IS_PACKED(array)) {
	if (HT_IS_WITHOUT_HOLES(array)) {
	return 1;
	}

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@iluuu1994 @TimWolla you participated in the discussion on #18291 - thoughts on adding this as a new flag?

[alecpl]

A packed array is one with consecutive integer indexes, basically an array that would pass https://www.php.net/manual/en/function.array-is-list.php - see

php-src/Zend/zend_hash.h

Lines 1612 to 1615 in 9898293

	if (HT_IS_PACKED(array)) {
	if (HT_IS_WITHOUT_HOLES(array)) {
	return 1;
	}

This proves my point. A packed array can have holes, therefore using that name here is wrong and confusing. Also, if you search php documentation sources for "packed array" you'll find almost nothing. So, people don't know what a "packed array" really is.

If there's a vote I'd vote yes for this, but not with the proposed const name.

[iluuu1994]

The standard terminology is "preserve keys". You'd need the inverse, so maybe "discard keys".

Ergonomically, I'm not sure this is much better than array_values(array_filter(...)) (or now array_filter(...) |> array_values(...)). In terms of performance, it might be possible to transform this call sequence to more optimized function under the hood (i.e. one that performs the transformation without an intermediate array). This would help for everybody using the existing pattern without migrating their code.

But I don't have any strong feelings on adding the flag itself.