thoemo/calc (1.2.3)
Installation
{
"repositories": [{
"type": "composer",
"url": "composer config repositories.thoemo composer composer require thoemo/calc:1.2.3About this package
thoemo/calc
Small combinatorics helpers: generate all k-element combinations of an array, and convert between a set of numbers and its position in the ordered list of all such sets (lottery style, e.g. 6 out of 49).
Requirements
- PHP >= 8.2, no extensions or other packages required
Installation
The package is served by the Forgejo Composer registry. Add the repository to your
composer.json:
"repositories": {
"packages.link.thoemo.net/thoemo": {
"type": "composer",
"url": "https://packages.link.thoemo.net/api/packages/thoemo/composer"
}
}
Then require the package:
composer require thoemo/calc
The PHP namespace is elnebuloso\Calc.
Overview
| Class | Description |
|---|---|
Combinations |
generate(array $elements, int $length): Generator yields every combination of $length elements. |
NumbersCombinations |
Maps a sorted set of numbers from a range to its 1-based combination number and back. |
Both classes only have static methods.
Usage
Generate combinations
Combinations::generate() yields each combination as an array, in the order of the input
elements. The input must be a list (keys 0..n-1).
use elnebuloso\Calc\Combinations;
foreach (Combinations::generate(["a", "b", "c", "d"], 2) as $combination) {
echo implode("", $combination), " ";
}
// ab ac ad bc bd cd
echo iterator_count(Combinations::generate([1, 2, 3, 4, 5, 6, 7], 5)); // 21
Number of a combination and back
Combinations of $length numbers out of $rangeMin..$rangeMax are numbered from 1 in
ascending order: for 6 out of 49, [1, 2, 3, 4, 5, 6] is 1, [1, 2, 3, 4, 5, 7] is 2 and
[44, 45, 46, 47, 48, 49] is 13983816.
use elnebuloso\Calc\NumbersCombinations;
NumbersCombinations::getCombination([2, 6, 12, 41, 47, 49], 1, 49); // 2217543
NumbersCombinations::getNumbers(2217543, 1, 49, 6); // [2, 6, 12, 41, 47, 49]
Pass the numbers to getCombination() in ascending order. A number outside the range throws an
InvalidArgumentException (Number not in range: 50).
Development
Tests and tools run through redo, the Docker-based CI wrapper; build.yml holds the project's
redo properties (default PHP version 8.2).
redo composer:install phpunit # PHPUnit with the PHP version from build.yml
redo composer:install phpunit -Dphp_version=8.4 # PHPUnit with another PHP version
redo phplint -Dphp_version=8.4
The coverage report is written to build/reports/phpunit/all/coverage/html.
Releases
Every push to main runs the GitLab pipeline (phplint, prettier, composer:validate:require
and PHPUnit on PHP 8.2 to 8.5), raises the patch version in VERSION and uploads that version
to the Forgejo registry. The released archive contains only README.md, composer.json and
src/.
Dependencies
Dependencies
| ID | Version |
|---|---|
| php | >=8.2 |