Re: [PHP-DEV] [RFC] array_search_range() function

On سه‌شنبه ۱۸ اوت ۲۰۲۶، ۲۰:۳۴ Rowan Tommins [IMSoP] <[email protected]>
wrote:

> On 18 August 2026 16:08:58 BST, "Rowan Tommins [IMSoP]" <
> [email protected]> wrote:
> >In fact, the simplest starting point would be no functions at all, just
> an optimised ArraySliceIterator. The actual search part is fairly easy to
> write in user code.
> >
> >Then in a separate RFC, add a new set of functions like "iter_search",
> "iter_any", etc, which would be useful with *any* iterator, not just this
> specific one.
>
>
> Just to add, both ArraySliceIterator and iter_search can be implemented in
> less than twenty lines of code each: <https://3v4l.org/HmYZV>
>
> Which is great for adding them natively: users of older versions or who
> need to support multiple versions can "polyfill" them to start using
> straight away, and then get more optimised versions when they upgrade.
>
> To be fair, the same is true of array_search_range: a memory-efficient
> user implementation is simple, but can't be quite as time-efficient as an
> internal one because it can't use optimisations based on the memory layout
> of the array. Only lightly tested, but covers all of the proposed signature
> in about 30 lines: <https://3v4l.org/VAsXY>
>
> For the archive, here's the sample implementations:
>
> ```
> class ArraySliceIterator implements IteratorAggregate {
>         private LimitIterator $backingIterator;
>
>         public function __construct(array $array, int $offset, int $limit)
> {
>                 $this->backingIterator = new LimitIterator(
>                         new ArrayIterator($array),
>                         $offset,
>                         $limit
>                 );
>         }
>
>         public function getIterator(): Traversable
>         {
>                 return $this->backingIterator;
>         }
> }
>
> function iter_search(mixed $needle, iterable $haystack, bool $strict =
> false): int|string|false
> {
>         foreach ( $haystack as $key => $value ) {
>                 if (
>                         ( $strict && $value === $needle )
>                         ||
>                         ( ! $strict && $value == $needle )
>                 ) {
>                         return $key;
>                 }
>         }
>         return false;
> }
>
> function array_search_range(
>     mixed $needle,
>     array $haystack,
>     int $offset = 0,
>     ?int $length = null,
>     bool $strict = false,
> ): int|string|false {
>         if ( $offset < 0 ) {
>                 $offset = count($haystack) + $offset;
>         }
>         if ( $length < 0 ) {
>                 $length = count($haystack) + $length - $offset;
>         }
>
>         $currentOffset = -1;
>         foreach ( $haystack as $key => $value ) {
>                 $currentOffset++;
>                 if ( $currentOffset < $offset ) {
>                         continue;
>                 }
>                 if ( $length !== null && $currentOffset >= $offset +
> $length ) {
>                         break;
>                 }
>                 if (
>                         ( $strict && $value === $needle )
>                         ||
>                         ( ! $strict && $value == $needle )
>                 ) {
>                         return $key;
>                 }
>         }
>         return false;
> }
> ```
>
> Regards,
>
> Rowan Tommins
> [IMSoP]
>


‐--------

Hey Rowan,

Man, I owe you one — seriously, thanks a lot for this!

Your point about the polyfill was genuinely brilliant. It actually made

me realize I was overcomplicating things. I went ahead and added a

“Polyfill” section to the RFC, so anyone on an older PHP version can

just copy-paste it and start using the function right away. No blockers

for adoption anymore.

And you hit the nail on the head about the memory layout thing — that’s

exactly why the native version still matters. The userland polyfill is

memory-friendly, but it walks element-by-element through the iterator.

The internal one goes straight at the HashTable and stops the moment it

finds a match. That’s the whole story in one sentence, honestly.

Here’s the updated RFC:

https://wiki.php.net/rfc/array_search_range

Would love to hear what you think of the new section.

Cheers,

Sepehr

>