On 01.01.21 20:22, Go Kudo wrote:
> Hi Marc, and sorry for the late reply. Email has been marked as spam...
>
>> I would expect the Random number generator to implement from Iterator
> using an integer for current() value
>> and providing utility functions (simple functions or methods of another
> class) for shuffle, random array entry like this:
>
> Thank you very much. This suggestion makes sense and looks very structured.
>
> However, I feel that in the PHP world, this structuring is a bit too much.
> Ease of use is very important in PHP.
One important reason for a PRNGInterface is (at least how I understand
it) to allow implementing PRNG algorithms in userland but there would be
no performant way to use this for shuffle and friends that's why I think
such functions should consume any PRNGInterface instead of building it
directly into the PRNG class.
-> If you really want these as PRNG methods - one possibility could be a
Trait providing these methods but this is very exotic for core
functionalities.
Another thing with the proposed `next*` methods is
* How to get the current value? retrieving the next value only seems to
be out of sync with the current PHP way (Iterator, Generator)
* `nextByte(int $length)` How much values does this consume? How much
random bytes can be generated with one value (4 bytes, 8 bytes, platform
dependent). Does this consume multiple values to generate 1 byte 4/8 times?
* same for `nextDouble()` on 32 bit platforms
* Btw. it should be called `nextFloat()` as there is no double type in
PHP and the float type is equivalent to C double precision
>
> Nevertheless, I am satisfied with this proposal. I'd like to hear from
> someone who is more familiar with the PHP context about the form of the
> implementation.
>
> But, it may be faster to actually hold a vote to ask this question. I'm not
> sure how much support this proposal has at this point, but do you think
> it's worth a try?
I'm don't have voting rights and I'm not very active in discussions so I
would be better to get some reasonable thoughts from someone more involved.
Cheers
Marc
>
>
> 2020年12月29日(火) 18:26 Marc <marc@mabe.berlin>:
>
>> Hi zeriyoshi,
>> On 23.12.20 14:41, zeriyoshi wrote:
>>
>> Thanks tyson.
>>
>>
>> This would also make it easier to use those generators in brand new
>>
>> algorithms that weren't in the ionitial RFC.
>>
>> (or in algorithms written by users in PHP)
>>
>> This suggestion seems to make sense. Maybe the RNG should only focus on
>> generating random numbers and not anything else.
>> However, the fact that array and string manipulation functions are no
>> longer native to C may have a speed disadvantage.
>>
>> So I came up with the idea of minimizing the interface definition as RNG.
>>
>> ```
>> interface PRNGInterface
>> {
>> public function nextInt(?int $min = null, ?int $max = null): int;
>> public function nextDouble(): double; // maybe, non-needed.
>> public function nextByte(int $length): string;
>> }
>> ```
>>
>> The methods for array and string operations are defined separately as
>> interfaces that inherit from the interface.
>>
>> ```
>> interface RandomInterface extends PRNGInterface
>> {
>> public function shuffle(array &$array): bool;
>> public function arrayRand(array $array, int $num = 1): int|string|array;
>> public function strShuffle(string $string): string;
>> }
>> ```
>>
>> This can be overly structured, but it will serve all purposes.
>>
>> Personally I feel the interfaces still looking a bit off to me.
>>
>> I would expect the Random number generator to implement from Iterator
>> using an integer for `current()` value
>>
>> and providing utility functions (simple functions or methods of another
>> class) for shuffle, random array entry like this:
>>
>> ```php
>>
>> interface RNG extends Iterator {
>> public function rewind();
>> public function next();
>> public function current(): int;
>> public function key(): int;
>> public function valid();
>> }
>>
>>
>> interface PRNG extends RNG {
>> public function __current(int $seed);
>> public function getSeed(): int;
>> }
>>
>> class RNGUtil {
>> public static function shuffleArray(int $randomNumber, array $arr):
>> array;
>> public static function randomArrayElement(int $randomNumber, array
>> $arr): mixed;
>> public static function between(int $randomNumber, int $min =
>> PHP_INT_MIN, int $max = PHP_INT_MAX): int;
>> public static function bytes(RNG $rng, int $length): string;
>> }
>>
>> ```
>>
>>
>> Regards,
>> Go Kudo
>>
>>
>> 2020年12月23日(水) 0:40 tyson andre <tysonandre...@hotmail.com>
>> <tysonandre...@hotmail.com>:
>>
>>
>> Hi Go Kudo,
>>
>> **A possible alternative that is widely used in other programming
>> languages is to limit the interface API to only generating bytes/integers,**
>> and to provide global functions that would use generic random number
>> generator objects (from internal or user-provided code) in their algorithms.
>>
>> This would also make it easier to use those generators in brand new
>> algorithms that weren't in the initial RFC.
>> (or in algorithms written by users in PHP)
>>
>> This alternative is similar to
>> Javahttps://docs.oracle.com/javase/7/docs/api/java/util/Collections.html#shuffle(java.util.List,%20java.util.Random)
>> and https://docs.oracle.com/javase/7/docs/api/java/util/Random.html
>> and C++ https://www.cplusplus.com/reference/algorithm/shuffle/
>> where the algorithms accept a random number generator conforming to some
>> interface
>> and Python https://docs.python.org/3/library/random.html#random.shuffle
>>
>> ```
>> interface PRNGInterface {
>> public function random[Signed]Int(): int; // between PHP_INT_MIN and
>> PHP_INT_MAX (4 bytes or 8 bytes)
>> public function randomBytes(int $length): string // $length bytes of
>> raw data
>> // possibly randomByte(): int // between 0 and 255
>> // public function randomIntInRange(int $min, int $max)
>> // __serialize(), __unserialize() may be provided, but may be
>> counterproductive for classes that wrap /dev/urandom or random_bytes()?
>> }
>> // possibly provide a trait that provides defaults based on abstract
>> function randomInt
>>
>> function whateverprefixornamespace_rand(PRNGInterface $rng, [int $min, int
>> $max]): int {}
>> // If this is intended to be secure, whateverprefix_array_rand may need to
>> avoid the optimizations used by array_rand for sparse arrays
>> function whateverprefixornamespace_array_rand(PRNGInterface $rng, array
>> $array, ...): int {}
>> function whateverprefixornamespace_shuffle(PRNGInterface $rng, array
>> &$array): bool;
>> // alternately might be possible by extending existing global functions
>> with an optional parameter
>> ```
>>
>> Thanks,
>> - Tyson
>>
>>
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