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Date: Sun, 17 Jan 2021 20:02:51 +0900
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Subject: Re: [RFC] Object-scope RNG implementation
From: zeriyoshi@gmail.com (Go Kudo)

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Updated the RFC and fixed the implementation.
Also made some additions to the RFC about when this feature might be useful=
.

RFC: https://wiki.php.net/rfc/object_scope_prng
Implementation PR: https://github.com/php/php-src/pull/6568 (All CI passed)

The main points are as follows:

- The implementation now meets all requirements. (maybe)
- Implemented MT19937, which is compatible with PHP standard MT. The
consistency of these is ensured by tests.
- The implementation is now what we used to call TypeII.
- All RNG implementations can now be inherited like regular classes. Use
faster calls only if the class is an internal class.
- The implementation has been heavily modified and the quality of the code
has been improved.

Currently, there are a few concerns:

- MT19937 returns a signed 32bit number as a result of the `next()` method;
the mt_rand() function returns a bit-shifted unsigned 31bit number, so the
results are not identical.
    - You can get the equivalent result with `$rng->next() << 1 &
PHP_INT_MAX`, but maybe you should have a `nextUnsigned31()` method.
    - Currently, the test uses `$rng->next() << 1 & PHP_INT_MAX`.
- The implementation of MT19937 is redundant. This can be merged.

Anyway, I think the code is finally ready for review.
Once that is done, we will start voting on RFCs.

Regards,
Go Kudo

2021=E5=B9=B41=E6=9C=889=E6=97=A5(=E5=9C=9F) 19:00 Go Kudo <zeriyoshi@gmail=
.com>:

> Hi internals.
>
> I think I'm ready to discuss this RFC.
> https://wiki.php.net/rfc/object_scope_prng
>
> Previous internals thread: https://externals.io/message/112525
>
> Now is the time to let me know what you think.
>
> Regards,
> Go Kudo
>

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