Hey:
On Sat, Jan 17, 2015 at 12:37 PM, Rasmus Lerdorf <ras...@lerdorf.com> wrote:
> On Jan 16, 2015, at 19:18, Xinchen Hui <larue...@php.net> wrote:
>>
>> Hey:
>>
>>
>>> On Sat, Jan 17, 2015 at 8:20 AM, Rasmus Lerdorf <ras...@lerdorf.com> wrote:
>>>> On 01/16/2015 03:54 PM, Simon J Welsh wrote:
>>>> That’s an invalid comparison function. It causes the current usort to
>>>> reverse sort the array and I see no problem with that changing (you’re
>>>> saying that a value for $a less than $b is in fact greater than it, and a
>>>> value of $b less than or equal to $a is equal to it).
>>>
>>> Your didn't make much sense. But yes, I am aware it is a weird
>>> comparison function taken from an existing app which is now broken under
>>> PHP7 but it only breaks if the array grows beyond 16 elements.
>>> If we are going to make a BC change here, it shouldn't be in a way that
>>> is dependent on the size of the array being sorted.
>>
>> I suggest you use :
>>
>> function cmp($a,$b) {
>> return strtotime($a['date']) - strtotime($b['date']);
>> }
>>
>> as our usort doc said:
>>
>> "The comparison function must return an integer less than, equal to,
>> or greater than zero if the first argument is considered to be
>> respectively less than, equal to, or greater than the second."
>>
>> otherwise, it's not a defined behavior
>
> Yes, like I said, I am aware that the comparison function is flaky but it is
> still code that has worked for 15 years so we have to be clear about the BC
> break. The fact that it works up until the array gets more than 16 elements
> makes it a tricky one to track down for people. With the massive volume of
> legacy code out there we have to be careful with changes like this that can
> break existing code, even if that code is questionable.
>
> At the very least we need a clear note in the upgrading doc reminding people
> to check all their user comparison functions.
Hey:
hmm, I am not sure about "BC break previous undefined behavior"
but okey, I agree we need write some note(actually I noted in UPGRADE
of we are using hybrid sorting algo now)..
but what kindof note I mean how details it should be? I am not a
native english speaker, could anyone here to help me to write that ?
thanks
>
> -Rasmus
--
Xinchen Hui
@Laruence
http://www.laruence.com/
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