Re: [RFC] Combined Comparison Operator

On 2/12/14, 11:25 PM, Yasuo Ohgaki wrote:

Hi Davey, On Thu, Feb 13, 2014 at 12:58 PM, Davey Shafik <davey@php.net> wrote:

I've written up an RFC/Patch to gauge interest and get feedback on the addition of a combined comparison (aka: spaceship) operator. You can see the RFC at: https://wiki.php.net/rfc/ combined-comparison-operator This adds a new operator "(expr) <=> (expr)" that returns 0 if both operands are equal, 1 if the left is greater, and -1 if the right is greater. It works with all types (just as well as <, <=, >=, > work) and is great for usort() callbacks for example. Code available here (against 5.6): https://github.com/dshafik/ php-src/compare/add-spaceship-operator I'd love to get this into 5.6, not sure if we hit feature freeze yet. Also, not sure if it needs 2/3 majority, but assumed so as pow did? Thoughts? If there is interest, I'll start adding tests. They should be fairly trivial.

Interesting shortcut operator. I feel closure function is for the task. I would vote 0, but close to -1 since it's only useful for sorting. Is there any other use cases? Regards, -- Yasuo Ohgaki yohgaki@ohgaki.net

Yasuo, Sorting is definitely it's most compelling use. It cuts down on potentially quite a bit of code: function ($left, $right) {

    if ($left[1] == $right[1]) {
         return 0;
    }

    if ($left[1] > $right[1]) {
         return 1;
    }

    if ($left[1] < $right[1]) {
        return -1;
    }

} or (as per the RFC): function ($left, $right) {

    return $left[1] <=> $right[1];

}