rfc:random_extension_improvement
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| rfc:random_extension_improvement [2022/06/17 19:52] – fix: array_rand replacement method vote zeriyoshi | rfc:random_extension_improvement [2022/07/22 09:55] (current) – reword two issues as the problem (VS the proposed solution) guilliamxavier | ||
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| ====== PHP RFC: Random Extension Improvement ====== | ====== PHP RFC: Random Extension Improvement ====== | ||
| - | * Version: 1.0 | + | * Version: 1.5.4 |
| * Date: 2022-06-16 | * Date: 2022-06-16 | ||
| * Author: Go Kudo < | * Author: Go Kudo < | ||
| - | * Status: | + | * Status: |
| * First Published at: http:// | * First Published at: http:// | ||
| ===== Introduction ===== | ===== Introduction ===== | ||
| - | There are several | + | Several |
| - | + | ||
| - | Key issues include: | + | |
| ==== Engine implementations are not final ==== | ==== Engine implementations are not final ==== | ||
| - | The Random Extension has classes that are natively implemented as RNG engines, but they are not marked as final. | + | The Random Extension has classes that are natively implemented as RNG engines, but they are not marked as <php>final</ |
| This allows classes to be created that inherit from native classes, but as stated in the previous RFC, user-implemented engines are inferior to native classes in terms of execution efficiency. This is true even for inheritance without method overrides, which often leads to confusion. | This allows classes to be created that inherit from native classes, but as stated in the previous RFC, user-implemented engines are inferior to native classes in terms of execution efficiency. This is true even for inheritance without method overrides, which often leads to confusion. | ||
| - | The extension already provides a Random\Engine interface with a single generate(): string method. | + | The extension already provides a '' |
| Even if the native classes are made final, it is easy for the user to create an alternative class using delegates. | Even if the native classes are made final, it is easy for the user to create an alternative class using delegates. | ||
| This is clearly an API design error, and the native implementations of the interface should be marked as final. | This is clearly an API design error, and the native implementations of the interface should be marked as final. | ||
| - | ==== Randomizer lacks array_rand() replacement method | + | ==== Random\SerializableEngine is not useful |
| - | array_rand() uses RNG internally, but there is no alternative method | + | This interface is a remnant from when the < |
| - | As per the previous RFC, this was the intent, but upon further investigation, | + | |
| - | However, the name of the method may need to be reconsidered. How about Randomizer:: | + | For this reason, remove '' |
| - | ==== " | + | This means that an Engine that implements SerializableEngine will no longer implement it. |
| + | However, serializability is determined by the implementation of the magic method in current PHP, so it has no effect. | ||
| - | In PHP, " | + | ==== Random\Engine\CombinedLCG |
| - | Therefore, it may be better to change the alternative method of str_shuffle(), Randomizer:: | + | The newly added '' |
| + | However, this algorithm | ||
| - | ==== PCG64 is ambiguous ==== | + | In order to preserve the implementation of the lcg_value() function, the internal implementation |
| - | The Random Extension has implemented PCG64 as a new PRNG, but it is officially one variant | + | ==== There is no equivalent |
| - | Therefore, change | + | < |
| + | As per the previous RFC, this was the intent, but upon further investigation, | ||
| - | ==== Mersenne Twister is ambiguous ==== | + | So add a method < |
| - | When PCG makes the choice to reflect a more detailed implementation in the name, Random\Engine\MersenneTwister is also an issue at the same time. | + | It may look incompatible with < |
| - | Random\Engine\MersenneTwister is precisely an implementation of the MT19937 algorithm. | + | <code php> |
| + | $array = [' | ||
| - | MT19937 also has an algorithm called MT19937_64 that generates 64-bit values. If for some reason MT19937_64 were to be implemented, the fact that the name Mersenne Twister is already in use could be problematic. | + | // Before: |
| + | mt_srand(1234, MT_RAND_PHP); | ||
| + | $single = array_rand($array); | ||
| + | $multiple = array_rand($array, | ||
| - | ==== PCG is not so famous ==== | + | // After: |
| + | $engine | ||
| + | $randomizer | ||
| + | $single | ||
| + | // or: [$single] | ||
| + | $multiple | ||
| + | </ | ||
| - | PCG is a very good algorithm, boasting great randomness and performance. | + | ==== " |
| - | However, I think its name recognition | + | In PHP, " |
| - | Therefore, | + | Therefore, |
| - | ==== Classnames | + | ==== Engine classnames |
| - | PHP applies strict PascalCase to class names. However, the previous RFC implementation does not properly meet the requirements. | + | To clearly identify the implemented algorithm, the PCG64 and MersenneTwister engines should be renamed to their canonical upstream name: |
| - | So, rename the class as follows: | + | * '' |
| + | * '' | ||
| - | * Random\Engine\CombinedLCG -> Random\Engine\CombinedLcg | + | ==== PCG is not so famous ==== |
| - | * Random\Engine\PCG64 -> Random\Engine\Pcg64 (or PcgOneseqXslRr64) | + | |
| - | * (Random\Engine\MT19937 | + | PCG is a very good algorithm, boasting great randomness and performance. |
| + | However, I think its name recognition is in some ways inferior to Vigna' | ||
| + | |||
| + | Therefore, I reimplement %%Xoshiro256**%%, which was previously mentioned as a candidate, and create the class '' | ||
| ===== Proposal ===== | ===== Proposal ===== | ||
| Line 73: | Line 87: | ||
| ==== Engine implementations are not final ==== | ==== Engine implementations are not final ==== | ||
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| </ | </ | ||
| - | ==== Randomizer lacks array_rand() replacement method | + | ==== Random\SerializableEngine is not useful |
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| </ | </ | ||
| - | ==== " | + | ==== Random\Engine\CombinedLCG is low quality |
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| </ | </ | ||
| - | ==== PCG64 is ambiguous | + | ==== There is no equivalent of array_rand() |
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| </ | </ | ||
| - | ==== Mersenne Twister is ambiguous | + | ==== " |
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| </ | </ | ||
| - | ==== PCG is not so famous | + | ==== Engine classnames are not precise |
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| </ | </ | ||
| - | ==== Classnames are not canonicalized | + | ==== PCG is not so famous |
| - | <doodle title=" | + | <doodle title=" |
| * Yes | * Yes | ||
| * No | * No | ||
| Line 122: | Line 136: | ||
| ===== Backward Incompatible Changes ===== | ===== Backward Incompatible Changes ===== | ||
| - | The following names have been reserved and will no longer be available | + | The following names have been reserved and will no longer be available: |
| + | |||
| + | * Random\Engine\Mt19937 | ||
| + | * Random\Engine\PcgOneseq128XslRr64 | ||
| + | * Random\Engine\Xoshiro256StarStar | ||
| + | |||
| + | The following class names will be made available again: | ||
| - | * Random\Engine\Pcg64OneseqXslRr64 | + | * Random\Engine\CombinedLCG |
| - | * Random\Engine\Xoshiro256StarStar (optional) | + | * Random\Engine\MersenneTwister |
| - | * Random\Engine\MT19937 | + | * Random\Engine\PCG64 |
| + | * Random\SerializableEngine | ||
| ===== Proposed PHP Version(s) ===== | ===== Proposed PHP Version(s) ===== | ||
| Line 148: | Line 169: | ||
| ===== Patches and Tests ===== | ===== Patches and Tests ===== | ||
| - | currently none | + | * https:// |
| ===== References ===== | ===== References ===== | ||
| * https:// | * https:// | ||
rfc/random_extension_improvement.1655495572.txt.gz · Last modified: 2022/06/17 19:52 by zeriyoshi