PHP RFC: Counting of non-countable objects

• Version: 0.3
• Date: 2016-10-04
• Author: Craig Duncan git@duncanc.co.uk
• Proposed version: PHP 7.2
• Status: Under Discussion
• ML thread: http://externals.io/thread/350

Calling count() on a scalar or object that doesn't implement the Countable interface (http://php.net/manual/en/class.countable.php) returns 1. There are no known use cases for this, and it can easily hide bugs, take the following example:

function handle_records(iterable $iterable)
{
    if (count($iterable) === 0) {
        return handle_empty();
    }
 
    foreach ($iterable as $value) {
        handle_value($val);
    }
}

Passing a Generator that yields nothing would not call handle_empty(), or handle_value(), or alert the developer to the issue.

This RFC proposes deprecating count with a parameter that is a scalar, null, or an object that doesn't implement Countable.

Note that the sizeof alias is also affected. http://php.net/manual/en/function.sizeof.php

None, deprecating features does not break BC.

PHP 7.2

Simple Yes/No vote that doesn't change the language itself so requires 50% + 1 votes to get 'accepted'.

Patch to handle the change: https://github.com/duncan3dc/php-src/commit/d253a1680361e63d070b324cf5a33493120f8050

Example tests: https://github.com/duncan3dc/php-src/commit/46a4f0061956f27ec195e3d497005a0a8c00ceb6

Initial discussion that led to this RFC's creation: https://github.com/php/php-src/pull/1672