Re: PR 287 - added use_keys argument to array_filter() [Discussion]

On Tue, Jun 18, 2013 at 11:27 AM, Leigh <leight@gmail.com> wrote: > On 18 June 2013 00:20, Sherif Ramadan <theanomaly.is@gmail.com> wrote: > >> I'm starting up a thread for discussion on Pull Request 287 >> https://github.com/php/php-src/pull/287 (allowing array >> keys to be passed >> to the callback function of array_filter through a third optional boolean >> argument). >> > > Why not use array_filter_keys? > > That actually isn't a bad idea. I would consider going that route if this patch presents any real world problems that could be better solved with introducing a new function. I just don't see any reason for a new function now given that this patch does not present any BC and can still solve the same problem without adding a new function. > There are many other array functions that work with keys using this naming > pattern. This would make it clearer in the code what is being filtered, and > no need for the additional parameter. > > The problem with having one callback for just the keys and another for the array elements is that you're stuck in a situation where you can't possibly use both. We have that problem with array sort functions that allow a user defined callback. For example, we have usort and uksort, but there is no sort function that can offer both. It's plausible that a user may be relying on both in certain cases (for a example a map of maps). > In this case I think I would still prefer it if the callback took a single > parameter. Values can still be easily looked up with $array[$key] in user > defined callbacks, but all of the built-in functions that take a single > parameter are still available to use. > I would like to solve the problem without introducing new problems. If I can do that we get PHP to take a step forward and not a step side-ways.