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Date: Mon, 31 Mar 2014 12:54:50 +0200
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To: Nikita Nefedov <inefedor@gmail.com>
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Subject: Re: [PHP-DEV] usort callback should always return integer (not float)
From: cryptocompress@googlemail.com (Crypto Compress)

Am 31.03.2014 11:00, schrieb Nikita Nefedov:
> Hi,
>
> I've just stumbled upon this limitation in sorting (compare) 
> callbacks. Is there any
> reason why we can't handle floats in this case?
>
> I think it would be nice to be able to return float from the callback
> because it's often happens that all it does is just `return
> $a->someMethod() - $b->someMethod();` (where someMethod() returns 
> float) or `return $a["something"] -
> $b["something"];` and to make it work I need to write additional if 
> statement. I think the reasoning could be complex behavior of doubles? 
> Especially comparing doubles. But will we see any double-related 
> pitfalls when all our code does with it is `return retval < 0 ? -1 : 
> retval > 0 ? 1 : 0;` (so essentially - compares them to zero)?
>
>
> I made a PR [1] on github for 5.6 version. I think this change is 
> pretty small and could go into 5.6 not breaking our release process 
> rules? Though it WILL introduce some BC breaks for userland code that 
> uses floats. But this code was already broken when it was relying on 
> old behavior.
>
> [1] https://github.com/php/php-src/pull/638
>

Hi,

try this:

<?php
$retval = 1.0 - 0.7 - 0.3;
var_dump($retval < 0 ? 'lt' : $retval > 0 ? 'gt' : 'equal'); // result 
is *not* equal

cryptocompress