This is a new thread for John Bafford's RFC which he mentioned on another thread, see below:
https://wiki.php.net/rfc/foreach_void <https://wiki.php.net/rfc/foreach_void> > On Aug 31, 2020, at 5:50 PM, John Bafford <jbaff...@zort.net> wrote: > > Hi Riikka, > >> On Aug 31, 2020, at 14:13, Riikka Kalliomäki <riikka.kalliom...@riimu.net> >> wrote: >> >> A common pattern that I've seen that could dearly use PHP internal >> optimization, if possible, would be: >> >> foreach (array_keys($array) as $key) { >> } > > I have a draft RFC (https://wiki.php.net/rfc/foreach_void) and patch > (https://github.com/jbafford/php-src/tree/foreachvoid against php 7.0, I > think) that helps with this, by allowing the following syntax: > > foreach($iterable as $key => void) { ... } > > This would iterate over the keys of the iterable, and does not retrieve the > values at all. > > In theory, this should be a general performance win any time one needs to > iterate over only the keys of an iterable, because it does not require the > use of an O(n) iteration and building of the array that array_keys() would, > plus it works on non-array types (such as generators or iterators). It also > is more performant than foreach($iterable as $key => $_) {}, because it omits > the opcode that instructs the engine to retrieve the value. (Presumably, a > future direction could include using this request to inform generators or > iterators to only return keys, and not values, which could further improve > performance, especially if value generation is expensive. But that is out of > scope for this RFC.) > > If this is something we'd like for PHP 8.1 and there are no major objections > to the idea, then after 8.0 is released, I can move the RFC out of Draft and > into Under Discussion, and presuming a vote passes, I'll update the patch as > necessary to work against 8.0. But my time is limited and I'm not willing to > put further time into the code unless an RFC vote passes. > > Thoughts anyone? +1 from me. BTW, your RFC says "Next PHP 7.x" for Proposed Version; might need to update that? -Mike
