Re: [RFC] Add is_list(mixed $value): bool to check for list-like arrays

> On Dec 20, 2020, at 9:09 PM, Ben Ramsey <ben@benramsey.com> wrote: > >> On Dec 19, 2020, at 19:43, tyson andre <tysonandre775@hotmail.com> >> wrote: >> >> It can be useful to verify that the assumption that array keys are >> consecutive integers is correct, both for data that is being passed >> into a module or for validating data before returning it from a >> module. However, because it's currently inconvenient to do that, this >> has rarely been done in my experience. > > I think there are some places where is_list() could be > unintuitive to > those who don’t understand some of the idiosyncrasies of PHP. > > For example, with > > $a = ['foo', 'bar', 'baz’]; > > is_list() will return true, but > if you run $a through asort(), > is_list() will return false > because the keys are no longer > consecutive integers, but is there any doubt this is still a list? > Maybe in a pure sense, it’s not, but I think this could be confusing. > > But now, if we do > > $b = array_merge($a, ['qux', 'quux']); > > $b is now back to being a list, so > is_list($b) returns true. > > While I understand the convenience is_list() provides--I myself > have > implemented the opposite of this numerous times (e.g., > is_dict())--it comes close to implying a data type that PHP > doesn’t > have, and I think this could give a false sense of type-safety-ness > when using this function to check whether something is a 0-indexed > array. > > Cheers, > Ben > Would either is_zero_based() or is_zero_indexed() be a reasonable name instead? -Mike P.S. See https://en.wikipedia.org/wiki/Zero-based_numbering <https://en.wikipedia.org/wiki/Zero-based_numbering>