On Thu, Sep 16, 2021 at 8:10 PM tyson andre <mailto:tysonandre...@hotmail.com> wrote: > > Hi internals, > > I've created a new RFC https://wiki.php.net/rfc/vector proposing to add > `final class Vector` to PHP. > > PHP's native `array` type is rare among programming language in that it is > used as an associative map of values, but also needs to support lists of > values. > In order to support both use cases while also providing a consistent internal > array HashTable API to the PHP's internals and PECLs, additional memory is > needed to track keys > (https://www.npopov.com/2014/12/22/PHPs-new-hashtable-implementation.html - > around twice as much as is needed to just store the values due to needing > space both for the string pointer and int key in a Bucket, for non-reference > counted values)). > Additionally, creating non-constant arrays will allocate space for at least 8 > elements to make the initial resizing more efficient, potentially wasting > memory. > > It would be useful to have an efficient variable-length container in the > standard library for the following reasons: > > 1. To save memory in applications or libraries that may need to store many > lists of values and/or run as a CLI or embedded process for long periods of > time > (in modules identified as using the most memory or potentially exceeding > memory limits in the worst case) > (both in userland and in native code written in php-src/PECLs) > 2. To provide a better alternative to `ArrayObject` and `SplFixedArray` for > use cases > where objects are easier to use than arrays - e.g. variable sized > collections (For lists of values) that can be passed by value to be read and > modified. > 3. To give users the option of stronger runtime guarantees that property, > parameter, or return values really contain a list of values without gaps, > that array modifications don't introduce gaps or unexpected indexes, etc. > > Thoughts on Vector? > > P.S. The functionality in this proposal can be tested/tried out at > https://pecl.php.net/teds (under the class name `\Teds\Vector` instead of > `\Vector`). > (That is a PECL I created earlier this year for future versions of iterable > proposals, common data structures such as Vector/Deque, and less commonly > used data structures that may be of use in future work on implementing other > data structures) > > Thanks, > Tyson > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php > I'm okay with a final Vector class in general. I don't love the proposed API but don't hate it either. Feedback on that at the end. What I would _love_ is a `vec` type from hacklang, which is similar to this but pass-by-value, copy-on-write like an array. Of course, this would require engine work and I understand it isn't as simple to add. Feedback on API: - `indexOf` returning `false` instead of `null` when it cannot be found. If we are keeping this method (which I don't like, because there's no comparator), please return `null` instead of false. The language has facilities for working with null like `??`, so please prefer that when it isn't needed for BC (like this, this is a new API). - `contains` also doesn't have a comparator. - Similarly but less strongly, I don't like the filter callable returning `mixed` -- please just make it `bool`. - I don't know what `setSize(int $size)` does. What does it do if the current size is less than `$size`? What about if its current size is greater? I suspect this is about capacity, not size, but without docs I am just guessing. -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
use SplFixedArray as vec; Done. ;) Olle
