Re: com php-src: Faster sorting algo: UPGRADING Zend/Makefile.am Zend/tests/methods-on-non-objects-usort.phpt Zend/zend_API.c Zend/zend_hash.c
Zend/zend_hash.h Zend/zend_ini.c Zend/zend_llist.c Zend/zend_qsort.c Zend/zend_qsort.h Zend/zend_sort.c Zend/zend_sort.h Zend/zend_ts_hash.c
Zend/zend_types.h configure.in ext/ereg/ereg.c ext/intl/collator/collator_sort.c ext/phar/dirstream.c ext/phar/phar_internal.h ext/standard/array.c
ext/standard/info.c ex

From: Date: Sat, 17 Jan 2015 05:16:39 +0000
Subject: Re: com php-src: Faster sorting algo: UPGRADING Zend/Makefile.am Zend/tests/methods-on-non-objects-usort.phpt Zend/zend_API.c Zend/zend_hash.c
Zend/zend_hash.h Zend/zend_ini.c Zend/zend_llist.c Zend/zend_qsort.c Zend/zend_qsort.h Zend/zend_sort.c Zend/zend_sort.h Zend/zend_ts_hash.c
Zend/zend_types.h configure.in ext/ereg/ereg.c ext/intl/collator/collator_sort.c ext/phar/dirstream.c ext/phar/phar_internal.h ext/standard/array.c
ext/standard/info.c ex
References: 1 2 3 4 5 6  Groups: php.internals 
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Hey: On Sat, Jan 17, 2015 at 12:37 PM, Rasmus Lerdorf <rasmus@lerdorf.com> wrote: > On Jan 16, 2015, at 19:18, Xinchen Hui <laruence@php.net> wrote: >> >> Hey: >> >> >>> On Sat, Jan 17, 2015 at 8:20 AM, Rasmus Lerdorf <rasmus@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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