Re: Add is_vectorlike($array) function

On 2 May 2017 at 11:55, Rowan Collins <rowan.collins@gmail.com> wrote: > On 02/05/2017 10:13, Jesse Schalken wrote: > >> Related to the optimisation made by Sara Golemon here: >> >> https://github.com/php/php-src/commit/c74bc87c74f48bc55541b3 >> bf2fc67d595f58a3b5 >> >> I often define a function like this, which checks if an array is "vector >> like" i.e. has keys 0,1,2..N: >> >> function is_vectorlike(array $a): bool { >> $i = 0; >> foreach ($a as $k => $v) { >> if ($k !== $i++) { >> return false; >> } >> } >> return true; >> } >> >> > +1, I've been thinking of making a similar suggestion. We can bikeshed the > name (it should certainly start with "array_"), but I think there's a very > good case for having an optimised implementation built in, given the > opportunities for short-cutting based on representation details. > > Wouldn't be better to introduce a new native type "vector"? I know it sounds obnoxious introducing a new basic data type, but I think having a workaround like is_vectorlike() wouldn't completely address the problem. Other than serializations I also felt, many many times, the need to also type-hint the input parameters with vector: function do_something(array $a) { if (!is_vectorlike($a)) throw new Exception("I don't like the input"); // do something with $a } I feel like going back to the dark ages when I had to manually check for is_string(), is_int() on the input parameters. Think how much better it would be to be able to: function do_something_ex(vector $a) { // do something with $a } Also it would be perfectly acceptable to implicitly cast a vector to an array, since a vector is basically a packed array. How does it sound? Complete madness? $a = [ "a", "b", "c" ]; is_vector($a); // true is_array($a); // true unset($a[1]); is_vector($a); // false is_array($a); // true