On 20/05/2021 05:59, Go Kudo wrote:
Thanks.
Deprecation will be done only to prevent unintended MT state dependent
code. We don't plan to go as far as removing the implementation for now.
I think every deprecation notice should mean a plan to remove. If you
just want to encourage people to discover the new functions, I'm not
sure a message in their logs every time mt_srand runs is the right way
to do it.
> Firstly, making these functions independent of mt_srand() is a
breaking change, so cannot happen until PHP 9.0 at the earliest.
To be honest, I don't understand how far PHP is willing to go to
accept disruptive changes.
The official policy is here: https://wiki.php.net/rfc/releaseprocess It
relies on the phrase "backwards compatibility", which is admittedly
quite hard to define.
You are right that the change from using rand() to using mt_rand() in
7.1 is arguably not backwards compatible. However, the following code
can be used to reproducibly shuffle two arrays in any version of PHP:
srand(123456);
shuffle($array1);
shuffle($array2);
The exact sequence returned will be different in 7.1 from 7.0, but
because srand() is now an alias of mt_srand(), it still affects the
shuffle() function in the expected way. If we switch shuffle() to an
algorithm that can't be seeded at all, this code will simply stop
working, and have to be completely rewritten.
A "polyfill" of sorts is possible, by storing an instance of the new
RNG\Randomizer in a global or static variable, but it's more than just a
find-and-replace, especially since many users will need to support
version 8.0 and 8.1 in the same code base.
As I said previously, I'm not convinced these functions need to stop
using the MT algorithm at all, and certainly see no reason to rush the
change.
Regards,
--
Rowan Tommins
[IMSoP]
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